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• Glenna, Susanne; Birkeland, Einar Elvbakken; Orr, Russell; Gilfillan, Gregor; Dalland, Marianne & Økstad, Ole Andreas Løchen [Show all 8 contributors for this article] (2026). Longitudinal analysis of the hand microbiome in response to chlorine-based antiseptic use during a military field exercise. Microbiology spectrum. 14(8). doi: 10.1128/spectrum.03771-25. Full text in Research Archive
• Orr, Russell; Brynildsrud, Ola Brønstad; Bøifot, Kari Oline; Gohli, Jostein; Skogan, Gunnar & Kelly, Frank J. [Show all 11 contributors for this article] (2026). Spatial and temporal patterns of public transit aerobiomes. Microbiome. 14(1), p. 1–22. doi: 10.1186/s40168-025-02303-7. Full text in Research Archive Show summary

  Background Aerobiome diversity is extensive; however, species-level community structure remains poorly resolved. Likewise, microbiomes of public transit systems are of public interest due to their importance for health, though few studies have focused on these ecosystems whilst utilising shotgun metagenomics. Aerosol studies have focused predominantly on individual cities, with limited between-city comparisons suggesting specific community structures. Longitudinal studies show aerobiome diversity as dynamic, fluctuating during seasonal and daily cycles, though interannual cycles remains to be considered. Further, a bacterial bias has limited fungal aerobiome studies, with few considering both fractions collectively. As such, the objective of this study was to examine spatial and temporal patterns in the species diversity of public transit aerobiomes, with an emphasis on bacteria and fungi. Results Air samples taken over a 3-year period (2017–2019) from six global cities were subjected to shotgun metagenomic sequencing. Improved classification databases, notably for fungi, applying stringent parameters for trimming, exogenous contamination removal and classification yielded high species-level resolution. Microbial diversity varied substantially among cities, while human and environmental factors, recorded in parallel, were of secondary significance. Bacteria dominated the public transit aerobiome with increased presence in cities with higher population densities. All aerobiomes had complex compositions, consisting of hundreds to thousands of species. Interannual variation had limited significance on the public transit aerobiome diversity and community structure. Conclusions Cities were the most important factor contributing to diversity and community structure, demonstrating specific bacterial and fungal signatures. Further, possible correlation between geographical distance and genetic signatures of aerobiomes is suggested. Bacteria are the most abundant constituent of public transit aerobiomes, though no single species is globally dominant, conversely indicating a large inter-city variation in community structure. The presence of a ubiquitous global species core is rejected, though an aerobiome sub-core is confirmed. For the first time, local public transit aerobiome cores are presented for each city and related to ecological niches. Further, the importance of a robust bioinformatics analysis pipeline to identify and remove exogenous contaminants for studying low-biomass samples is highlighted. Lastly, a core and sub-core definition of contaminant aerobiome species with taxon tables, to facilitate future environmental studies, is presented.

• Glenna, Susanne; Birkeland, Einar Elvbakken; Orr, Russell; Gilfillan, Gregor; Dalland, Marianne & Økstad, Ole Andreas [Show all 8 contributors for this article] (2025). Skin bacterial community dynamics of hands and forearms before and after military field exercise. Microbiology spectrum. 13(5). doi: 10.1128/spectrum.02953-24. Full text in Research Archive Show summary

  The human skin microbiome is crucial for health and immunity, especially under the extreme conditions military personnel face. Soldiers often encounter unique stressors and hygienic challenges that can alter their skin’s microbial composition, particularly in field environments. In this study, we aimed to investigate the impact of military field exercises on the diversity and composition of the skin bacterial microbiota using 16S rRNA sequencing. We conducted a longitudinal study of Norwegian soldiers (n = 19) participating in outdoor training operations during the NATO winter exercise Cold Response 2022. Skin swabs were taken from soldiers' hands and forearms before and after the 10-day military exercise, and following a 3-week post-exercise leave. Our results reveal hand- and forearm-specific shifts in bacterial populations associated with the exercise, likely influenced by environmental exposure, reduced hygiene, and heightened social contact. Alpha diversity increased on forearms while remaining stable on hands, which appeared more resilient to perturbations. Both sites exhibited temporal changes in composition, with soil- and water-associated bacteria enriched post-exercise; most being transient on hands but more sustained on forearms. The soldiers’ microbiomes converged during the exercise, then diverged in the post-exercise leave period, and neither skin site returned to baseline composition at follow-up. Our findings highlight the impact of collaborative outdoor activities on microbial communities and suggest that resilience and stability differ between skin sites. IMPORTANCE Optimizing soldier health and resilience is critical for maintaining military readiness and operational effectiveness. The skin, as the body’s first line of defense, is subjected to numerous challenges in military environments. Unique environmental and hygiene challenges can disrupt the skin microbiome and increase susceptibility to skin and soft tissue infections. This longitudinal research provides valuable insights into the effects of military service on the bacterial dynamics of the skin microbiome but can also inform hygiene management and disease prevention in comparable situations.

• Williamson, Kelsey; Eme, Laura; Baños, Hector; McCarthy, Charley G. P.; Susko, Edward & Kamikawa, Ryoma [Show all 11 contributors for this article] (2025). A robustly rooted tree of eukaryotes reveals their excavate ancestry. Nature. ISSN 0028-0836. 640, p. 974–981. doi: 10.1038/s41586-025-08709-5. Full text in Research Archive
• Williams, Shelby K.; Hultqvist, Jon Jerlström; Eglit, Yana; Salas-Leiva, Dayana E.; Curtis, Bruce & Orr, Russell [Show all 11 contributors for this article] (2024). Extreme mitochondrial reduction in a novel group of free-living metamonads. Nature Communications. 15(1). doi: 10.1038/s41467-024-50991-w. Full text in Research Archive Show summary

  Metamonads are a diverse group of heterotrophic microbial eukaryotes adapted to living in hypoxic environments. All metamonads but one harbour metabolically altered ‘mitochondrion-related organelles’ (MROs) with reduced functions, however the degree of reduction varies. Here, we generate high-quality draft genomes, transcriptomes, and predicted proteomes for five recently discovered free-living metamonads. Phylogenomic analyses placed these organisms in a group we name the ‘BaSk’ (Barthelonids+Skoliomonads) clade, a deeply branching sister group to the Fornicata, a phylum that includes parasitic and free-living flagellates. Bioinformatic analyses of gene models shows that these organisms are predicted to have extremely reduced MRO proteomes in comparison to other free-living metamonads. Loss of the mitochondrial iron-sulfur cluster assembly system in some organisms in this group appears to be linked to the acquisition in their common ancestral lineage of a SUF-like minimal system Fe/S cluster pathway by lateral gene transfer. One of the isolates, Skoliomonas litria, appears to have lost all other known MRO pathways. No proteins were confidently assigned to the predicted MRO proteome of this organism suggesting that the organelle has been lost. The extreme mitochondrial reduction observed within this free-living anaerobic protistan clade demonstrates that mitochondrial functions may be completely lost even in free-living organisms.

• Gordon, Dennis P.; Quek, Randolph Z B; Orr, Russell John Scott; Waeschenbach, Andrea; Huang, Danwei & Strano, Francesca [Show all 8 contributors for this article] (2023). Morphological diversity and a ribosomal phylogeny of Rhabdopleura (Hemichordata: Graptolithina) from the Western Pacific (Singapore and New Zealand), with implications for a re-evaluation of rhabdopleurid species diversity. Marine Biodiversity. ISSN 1867-1616. 53. doi: 10.1007/s12526-022-01310-3. Full text in Research Archive Show summary

  Abstract The recent discovery of Rhabdopleura in Singapore and the chance collecting of fresh material from northern New Zealand (Three Kings Shelf) provided an opportunity to sequence the specimens with an aim to determine their species identity. Phylogeny reconstructions of two new Rhabdopleura taxa based on ribosomal and mitochondrial genes suggest a different identity from known samples, including putative Rhabdopleura annulata , first described from the Three Kings Shelf but sequenced from the Great Barrier Reef. Pairwise distances between rhabdopleurids for the 16S rRNA locus were several magnitudes larger than that of 18S rRNA, and might potentially be a suitable barcoding gene once sufficient samples of conspecifics are collected to determine the barcoding gaps. Type material of R. annulata was re-examined, as well as Rhabdopleura material from eight other New Zealand localities from north of subtropical Raoul Island (Kermadec Ridge) at ~29° S to the subantarctic Campbell Plateau at ~49° S. Six morphological characters, four of them new, were applied to all samples. The findings from morphology suggest (1) the holotype and cotype of R. annulata might not be conspecific; (2) there are 3–4 variants (species?) on the Three Kings Shelf; and (3) there are 2–3 additional variants (species?) elsewhere in the New Zealand region.

• Orr, Russell John Scott; Martino, Emanuela Di; Ramsfjell, Mali Hamre; Gordon, Dennis P.; Berning, Björn & Chowdhury, Ismael [Show all 34 contributors for this article] (2022). Paleozoic origins of cheilostome bryozoans and their parental care inferred by a new genome-skimmed phylogeny. Science Advances. 8(13). doi: 10.1126/sciadv.abm7452. Full text in Research Archive Show summary

  Phylogenetic relationships and the timing of evolutionary events are essential for understanding evolution on longer time scales. Cheilostome bryozoans are a group of ubiquitous, species-rich, marine colonial organisms with an excellent fossil record but lack phylogenetic relationships inferred from molecular data. We present genome-skimmed data for 395 cheilostomes and combine these with 315 published sequences to infer relationships and the timing of key events among c. 500 cheilostome species. We find that named cheilostome genera and species are phylogenetically coherent, rendering fossil or contemporary specimens readily delimited using only skeletal morphology. Our phylogeny shows that parental care in the form of brooding evolved several times independently but was never lost in cheilostomes. Our fossil calibration, robust to varied assumptions, indicates that the cheilostome lineage and parental care therein could have Paleozoic origins, much older than the first known fossil record of cheilostomes in the Late Jurassic.

• Orr, Russell John Scott; Martino, Emanuela Di; Gordon, Dennis P.; Ramsfjell, Mali Hamre; Mello, Hannah & Smith, Abigail M. [Show all 7 contributors for this article] (2021). A broadly resolved molecular phylogeny of New Zealand cheilostome bryozoans as a framework for hypotheses of morphological evolution. Molecular Phylogenetics and Evolution. ISSN 1055-7903. 161. doi: 10.1016/j.ympev.2021.107172. Full text in Research Archive Show summary

  Larger molecular phylogenies based on ever more genes are becoming commonplace with the advent of cheaper and more streamlined sequencing and bioinformatics pipelines. However, many groups of inconspicuous but no less evolutionarily or ecologically important marine invertebrates are still neglected in the quest for understanding species- and higher-level phylogenetic relationships. Here, we alleviate this issue by presenting the molecular sequences of 165 cheilostome bryozoan species from New Zealand waters. New Zealand is our geographic region of choice as its cheilostome fauna is taxonomically, functionally and ecologically diverse, and better characterized than many other such faunas in the world. Using this most taxonomically broadly-sampled and statistically-supported cheilostome phylogeny comprising 214 species, when including previously published sequences, and 17 genes (2 nuclear and 15 mitochondrial) we tested several existing systematic hypotheses based solely on morphological observations. We find that lower taxonomic level hypotheses (species and genera) are robust while our inferred trees did not reflect current higher-level systematics (family and above), illustrating a general need for the rethinking of current hypotheses. To illustrate the utility of our new phylogeny, we reconstruct the evolutionary history of frontal shields (i.e., a calcified body-wall layer in ascus-bearing cheilostomes) and ask if its presence has any bearing on the diversification rates of cheilostomes.

• Andresen, Ina J.; Orr, Russell John Scott; Shalchian-Tabrizi, Kamran & Bråte, Jon (2021). Compartmentalization of mRNAs in the giant, unicellular green alga Acetabularia acetabulum. Algal Research. ISSN 2211-9264. 59. doi: 10.1016/j.algal.2021.102440. Full text in Research Archive Show summary

  Acetabularia acetabulum is a single-celled green alga which has historically been an important model system in cell biology. Here, we attempt to re-introduce A. acetabulum as a model system through the investigation of the subcellular localization of mRNAs. A. acetabulum is a macroscopic single-celled alga with a highly complex cellular morphology. The cell is gigantic, and the single nucleus, which is located at the basal end, is several centimeters away from the umbrella-shaped tip. To better understand the genetic basis of the morphology of this alga, we aimed to characterize the mRNA composition in four different subcellular regions of adult cells. Analyses of the quantitative gene expression data revealed a high degree of differentially distributed gene products. Gene transcripts involved in photosynthesis were mainly accumulated in the apical cap structure, while the basal end carrying the nucleus was enriched for nuclear processes such as DNA replication and transcription. Cytoskeletal components, intracellular transport and protein translation was present throughout this highly elongated cell. An important observation was that some gene transcripts were distributed throughout the cell while others, often functionally related transcripts, were localized in large pools at distinct subcellular regions. This suggests that post-transcriptional regulation and specific cellular localization of gene products may be important mechanisms behind morphogenesis in this gigantic cell.

• Andresen, Ina Jungersen; Orr, Russell John Scott; Krabberød, Anders Kristian; Shalchian-Tabrizi, Kamran & Bråte, Jon (2021). Genome sequencing and de novo assembly of the giant unicellular alga Acetabularia acetabulum using droplet MDA. Scientific Reports. 11. doi: 10.1038/s41598-021-92092-4. Full text in Research Archive
• Nilsson, Pernille; Solbakken, Monica Hongrø; Schmid, Boris Valentijn; Orr, Russell; Lv, Ruichen & Cui, Yujun [Show all 15 contributors for this article] (2020). The Genome of the Great Gerbil Reveals Species-Specific Duplication of an MHCII Gene. Genome Biology and Evolution (GBE). 12(2), p. 3832–3849. doi: 10.1093/gbe/evaa008. Full text in Research Archive Show summary

  Abstract The great gerbil (Rhombomys opimus) is a social rodent living in permanent, complex burrow systems distributed throughout Central Asia, where it serves as the main host of several important vector-borne infectious pathogens including the well-known plague bacterium (Yersinia pestis). Here, we present a continuous annotated genome assembly of the great gerbil, covering over 96% of the estimated 2.47-Gb genome. Taking advantage of the recent genome assemblies of the sand rat (Psammomys obesus) and the Mongolian gerbil (Meriones unguiculatus), comparative immunogenomic analyses reveal shared gene losses within TLR gene families (i.e., TLR8, TLR10, and the entire TLR11-subfamily) for Gerbillinae, accompanied with signs of diversifying selection of TLR7 and TLR9. Most notably, we find a great gerbil-specific duplication of the MHCII DRB locus. In silico analyses suggest that the duplicated gene provides high peptide binding affinity for Yersiniae epitopes as well as Leishmania and Leptospira epitopes, putatively leading to increased capability to withstand infections by these pathogens. Our study demonstrates the power of whole-genome sequencing combined with comparative genomic analyses to gain deeper insight into the immunogenomic landscape of the great gerbil and its close relatives.

• Orr, Russell; Sannum, Maja Margret; Boessenkool, Sanne; Martino, Emanuela Di; Gordon, Dennis & Mello, Hannah [Show all 10 contributors for this article] (2020). A molecular phylogeny of historical and contemporary specimens of an under‐studied micro‐invertebrate group. Ecology and Evolution. 11(1), p. 309–320. doi: 10.1002/ece3.7042. Full text in Research Archive Show summary

  Resolution of relationships at lower taxonomic levels is crucial for answering many evolutionary questions, and as such, sufficiently varied species representation is vital. This latter goal is not always achievable with relatively fresh samples. To alleviate the difficulties in procuring rarer taxa, we have seen increasing utilization of historical specimens in building molecular phylogenies using high throughput sequencing. This effort, however, has mainly focused on large‐bodied or well‐studied groups, with small‐bodied and under‐studied taxa under‐prioritized. Here, we utilize both historical and contemporary specimens, to increase the resolution of phylogenetic relationships among a group of under‐studied and small‐bodied metazoans, namely, cheilostome bryozoans. In this study, we pioneer the sequencing of air‐dried cheilostomes, utilizing a recently developed library preparation method for low DNA input. We evaluate a de novo mitogenome assembly and two iterative methods, using the sequenced target specimen as a reference for mapping, for our sequences. In doing so, we present mitochondrial and ribosomal RNA sequences of 43 cheilostomes representing 37 species, including 14 from historical samples ranging from 50 to 149 years old. The inferred phylogenetic relationships of these samples, analyzed together with publicly available sequence data, are shown in a statistically well‐supported 65 taxa and 17 genes cheilostome tree, which is also the most broadly sampled and largest to date. The robust phylogenetic placement of historical samples whose contemporary conspecifics and/or congenerics have been sequenced verifies the appropriateness of our workflow and gives confidence in the phylogenetic placement of those historical samples for which there are no close relatives sequenced. The success of our workflow is highlighted by the circularization of a total of 27 mitogenomes, seven from historical cheilostome samples. Our study highlights the potential of utilizing DNA from micro‐invertebrate specimens stored in natural history collections for resolving phylogenetic relationships among species.

• Orr, Russell; Haugen, Marianne Nilsen; Berning, Björn; Bock, Phil; Cumming, Robyn L. & Florence, Wayne [Show all 14 contributors for this article] (2019). A genome-skimmed phylogeny of a widespread bryozoan family, Adeonidae. BMC Evolutionary Biology. 19(235). doi: 10.1186/s12862-019-1563-4. Full text in Research Archive Show summary

  Background Understanding the phylogenetic relationships among species is one of the main goals of systematic biology. Simultaneously, credible phylogenetic hypotheses are often the first requirement for unveiling the evolutionary history of traits and for modelling macroevolutionary processes. However, many non-model taxa have not yet been sequenced to an extent such that statistically well-supported molecular phylogenies can be constructed for these purposes. Here, we use a genome-skimming approach to extract sequence information for 15 mitochondrial and 2 ribosomal operon genes from the cheilostome bryozoan family, Adeonidae, Busk, 1884, whose current systematics is based purely on morphological traits. The members of the Adeonidae are, like all cheilostome bryozoans, benthic, colonial, marine organisms. Adeonids are also geographically widely-distributed, often locally common, and are sometimes important habitat-builders. Results We successfully genome-skimmed 35 adeonid colonies representing 6 genera (Adeona, Adeonellopsis, Bracebridgia, Adeonella, Laminopora and Cucullipora). We also contributed 16 new, circularised mitochondrial genomes to the eight previously published for cheilostome bryozoans. Using the aforementioned mitochondrial and ribosomal genes, we inferred the relationships among these 35 samples. Contrary to some previous suggestions, the Adeonidae is a robustly supported monophyletic clade. However, the genera Adeonella and Laminopora are in need of revision: Adeonella is polyphyletic and Laminopora paraphyletically forms a clade with some Adeonella species. Additionally, we assign a sequence clustering identity using cox1 barcoding region of 99% at the species and 83% at the genus level. Conclusions We provide sequence data, obtained via genome-skimming, that greatly increases the resolution of the phylogenetic relationships within the adeonids. We present a highly-supported topology based on 17 genes and substantially increase availability of circularised cheilostome mitochondrial genomes, and highlight how we can extend our pipeline to other bryozoans.

• Orr, Russell; Zhao, Sen; Klaveness, Dag; Yabuki, Akinori; Ikeda, Keiji & Makoto, Watanabe M. [Show all 7 contributors for this article] (2018). Enigmatic diphyllatea eukaryotes: culturing and targeted PacBio RS amplicon sequencing reveals a higher order taxonomic diversity and global distribution. BMC Evolutionary Biology. 18(115), p. 1–13. doi: 10.1186/s12862-018-1224-z. Full text in Research Archive Show summary

  Background The class Diphyllatea belongs to a group of enigmatic unicellular eukaryotes that play a key role in reconstructing the morphological innovation and diversification of early eukaryotic evolution. Despite its evolutionary significance, very little is known about the phylogeny and species diversity of Diphyllatea. Only three species have described morphology, being taxonomically divided by flagella number, two or four, and cell size. Currently, one 18S rRNA Diphyllatea sequence is available, with environmental sequencing surveys reporting only a single partial sequence from a Diphyllatea-like organism. Accordingly, geographical distribution of Diphyllatea based on molecular data is limited, despite morphological data suggesting the class has a global distribution. We here present a first attempt to understand species distribution, diversity and higher order structure of Diphyllatea. Results We cultured 11 new strains, characterised these morphologically and amplified their rRNA for a combined 18S–28S rRNA phylogeny. We sampled environmental DNA from multiple sites and designed new Diphyllatea-specific PCR primers for long-read PacBio RSII technology. Near full-length 18S rRNA sequences from environmental DNA, in addition to supplementary Diphyllatea sequence data mined from public databases, resolved the phylogeny into three deeply branching and distinct clades (Diphy I – III). Of these, the Diphy III clade is entirely novel, and in congruence with Diphy II, composed of species morphologically consistent with the earlier described Collodictyon triciliatum. The phylogenetic split between the Diphy I and Diphy II + III clades corresponds with a morphological division of Diphyllatea into bi- and quadriflagellate cell forms. Conclusions This altered flagella composition must have occurred early in the diversification of Diphyllatea and may represent one of the earliest known morphological transitions among eukaryotes. Further, the substantial increase in molecular data presented here confirms Diphyllatea has a global distribution, seemingly restricted to freshwater habitats. Altogether, the results reveal the advantage of combining a group-specific PCR approach and long-read high-throughput amplicon sequencing in surveying enigmatic eukaryote lineages. Lastly, our study shows the capacity of PacBio RS when targeting a protist class for increasing phylogenetic resolution.

• Orr, Russell; Waeschenbach, Andrea; Enevoldsen, Emily; Boeve, Jeroen Pieter; Haugen, Marianne Nilsen & Voje, Kjetil L. [Show all 11 contributors for this article] (2018). Bryozoan genera Fenestrulina and Microporella no longer confamilial; multi-gene phylogeny supports separation. Zoological Journal of the Linnean Society. ISSN 0024-4082. p. 1–10. doi: 10.1093/zoolinnean/zly055. Full text in Research Archive Show summary

  Bryozoans are a moderately diverse, mostly marine phylum with a fossil record extending to the Early Ordovician. Compared to other phyla, little is known about their phylogenetic relationships at both lower and higher taxonomic levels. Hence, an effort is being made to elucidate their phylogenetic relationships. Here, we present newly sequenced nuclear and mitochondrial genes for 21 cheilostome bryozoans. Combining these data with existing orthologous molecular data, we focus on reconstructing the phylogenetic relationships of Fenestrulina and Microporella, two species-rich genera. They are currently placed in Microporellidae, defined by having a semicircular primary orifice and a proximal ascopore. Our six-gene phylogenetic analysis reveals that the genera Fenestrulina and Microporella are each monophyletic, with the sister clade to Microporella comprising non-microporellids. Our result hence supports the reinstatement of the family Fenestrulinidae Jullien, 1888 for Fenestrulina and genera with comparable frontal shield and ooecial morphologies. Our well-supported phylogeny, based on independent molecular data, lends credit to existing phylogenetic hypotheses based on morphological observations but does not conform to the current classification of these bryozoans. This illustrates the general need for a rethink of bryozoan higher level systematics, ideally based on both morphological and molecular data.

• Orr, Russell; Rombauts, Stephane; Peer, Yves Van de & Shalchian-Tabrizi, Kamran (2017). Draft genome sequences of two unclassified bacteria, Sphingomonas sp. strains IBVSS1 and IBVSS2, isolated from environmental samples. Microbiology Resource Announcements (MRA). 5:e00894-17(34), p. 1–3. doi: 10.1128/genomeA.00894-17. Full text in Research Archive
• Orr, Russell; Rombauts, Stephane; Peer, Yves Van de & Shalchian-Tabrizi, Kamran (2017). Draft genome sequences of two unclassified bacteria, Hydrogenophaga sp. strains IBVHS1 and IBVHS2, isolated from environmental samples. Microbiology Resource Announcements (MRA). 5(34). doi: 10.1128/genomeA.00884-17. Full text in Research Archive
• Orr, Russell; Rombauts, Stephane; Peer, Yves Van de & Shalchian-Tabrizi, Kamran (2017). Draft genome sequences of two unclassified Chitinophagaceae bacteria, IBVUCB1 and IBVUCB2, isolated from environmental samples. Microbiology Resource Announcements (MRA). 5(33), p. 1–3. doi: 10.1128/genomeA.00787-17. Full text in Research Archive
• Orr, Russell; Shalchian-Tabrizi, Kamran; Peer, Yves Van de & Rombauts, S (2017). Draft genome Sequences of two Unclassified Chitinophagaceae bacteria, IBVUCB1 and IBVUCB2, Isolated from Environmental Samples. Microbiology Resource Announcements (MRA). doi: 10.1128/genomeA.00787-17. Full text in Research Archive
• Orr, Russell; Shalchian-Tabrizi, Kamran; Peer, Yves Van de & Rombauts, S (2017). Draft Genome Sequences of Two Unclassified Bacteria, Sphingomonas sp. Strains IBVSS1 and IBVSS2, Isolated from Environmental Samples. Microbiology Resource Announcements (MRA). 5(34). doi: 10.1128/genomeA.00894-17. Full text in Research Archive
• Krabberød, Anders Kristian; Orr, Russell; Bråte, Jon; Kristensen, Tom; Bjørklund, Kjell Rasmus & Shalchian-Tabrizi, Kamran (2017). Single cell transcriptomics, mega-phylogeny and the genetic basis of morphological innovations in Rhizaria. Molecular Biology and Evolution (MBE). ISSN 0737-4038. doi: 10.1093/molbev/msx075. Full text in Research Archive Show summary

  The innovation of the eukaryote cytoskeleton enabled phagocytosis, intracellular transport and cytokinesis, and is responsible for the diversity of eukaryotic morphologies. Still, the relationship between phenotypic innovations in the cytoskeleton and their underlying genotype is poorly understood. To explore the genetic mechanism of morphological evolution of the eukaryotic cytoskeleton we provide the first single cell transcriptomes from uncultured, free-living unicellular eukaryotes: the polycystine radiolarian Lithomelissa setosa (Nassellaria) and Sticholonche zanclea (Taxopodida). A phylogenomic approach using 255 genes finds Radiolaria and Foraminifera as separate monophyletic groups (together as Retaria), while Cercozoa is shown to be paraphyletic. Analysis of the genetic components of the cytoskeleton and mapping of the evolution of these to the revised phylogeny of Rhizaria reveal lineage-specific gene duplications and neofunctionalization of α and β tubulin in Retaria, actin in Retaria and Endomyxa, and Arp2/3 complex genes in Chlorarachniophyta. We show how genetic innovations have shaped cytoskeletal structures in Rhizaria, and how single cell transcriptomics can be applied for resolving deep phylogenies and studying gene evolution in uncultured protist species.

• Murray, Shauna A.; Diwan, Rutuja; Orr, Russell; Kohli, Gurjeet S. & John, Uwe (2015). Gene duplication, loss and selection in the evolution of saxitoxin biosynthesis in alveolates. Molecular Phylogenetics and Evolution. ISSN 1055-7903. 92, p. 165–180. doi: 10.1016/j.ympev.2015.06.017. Full text in Research Archive
• Stø, Ida Myhrer; Orr, Russell; Fooyontphanich, Kim; Jin, Xu; Knutsen, Jonfinn Mordekai Blix & Fischer, Urs [Show all 9 contributors for this article] (2015). Conservation of the abscission signaling peptide IDA during Angiosperm evolution: Withstanding genome duplications and gain and loss of the receptors HAE/HSL2. Frontiers in Plant Science. 6(OCTOBER). doi: 10.3389/fpls.2015.00931. Full text in Research Archive
• Stensrud, Øyvind; Orr, Russell; Reier-Røberg, Kjetil; Schumacher, Trond & Høiland, Klaus (2014). Phylogenetic relationships in Cortinarius with focus on North European species. Karstenia. ISSN 0453-3402. 54(2), p. 57–71. doi: 10.29203/ka.2014.464. Full text in Research Archive Show summary

  Cortinarius is an ectomycorrhizal Agaricales genus with high diversity of which rDNA sequences of 86 species together with four outgroup taxa were investigated phylogenetically by aid of Maximum Likelihood and Bayesian analyses. The Cortinarius data set represents 81 taxa from the Northern Hemisphere showing the main variation spectrum among the species. In addition, five species from the Southern Hemisphere are included. The phylogenetic tree of Cortinarius gives statistical support to twelve monophyletic groups in the upper level. They are discussed in context of morphology, chemistry (secondary compounds), and ecology. The phylogenetic tree lacks, however, satisfactory support for its backbone. Several species could not be included in any group, especially those forming the basal framework of the tree. Of special interest is a “superclade” comprising eight of our monophyletic clades and two singletons. Here we find the majority of species with soluble pigments of octaketide origin, all species with compounds of nonaketide origin, the majority of species with hygrophaneous pileus, few species with viscid pileus, and no species with bulbous stipe base. Moreover, all species except one have duplex pileus cuticle. The morphological traits are not indicative for any clade, although some are more frequent in some clades than others. During the evolution they have been gained and lost several times. The chemical characteristics are – to a certain degree – more indicative for the clades. The evolution and ecological role of these compounds are discussed. Concerning the North European species, there are ecological differences between the clades, especially between clades specializing to rich or calcareous forests and clades specializing to poor forests or arctic-alpine environments.

• Murray, Shauna A.; Hoppenrath, Mona; Orr, Russell; Bolch, Christopher; John, Uwe & Diwan, Rutuja [Show all 11 contributors for this article] (2014). Alexandrium diversaporum sp. nov., a new non-saxitoxin producing species: Phylogeny, morphology and sxtA genes. Harmful Algae. ISSN 1568-9883. 31, p. 54–65. doi: 10.1016/j.hal.2013.09.005. Full text in Research Archive
• Orr, Russell; Stüken, Anke; Murray, Shauna A. & Jakobsen, Kjetill Sigurd (2013). Evolution and Distribution of Saxitoxin Biosynthesis in Dinoflagellates. Marine Drugs. 11(8), p. 2814–2828. doi: 10.3390/md11082814. Full text in Research Archive
• Orr, Russell; Stüken, Anke; Murray, Shauna A. & Jakobsen, Kjetill Sigurd (2013). Evolutionary Acquisition and Loss of Saxitoxin Biosynthesis in Dinoflagellates: the Second "Core" Gene, sxtG. Applied and Environmental Microbiology. ISSN 0099-2240. 79(7), p. 2128–2136. doi: 10.1128/AEM.03279-12. Full text in Research Archive Show summary

  Saxitoxin and its derivatives are potent neurotoxins produced by several cyanobacteria and dinoflagellate species. SxtA is the initial enzyme in the biosynthesis of saxitoxin. The dinoflagellate full mRNA and partial genomic sequences have previously been characterized, and it appears that sxtA originated in dinoflagellates through a horizontal gene transfer from a bacterium. So far, little is known about the remaining genes involved in this pathway in dinoflagellates. Here we characterize sxtG, an amidinotransferase enzyme gene that putatively encodes the second step in saxitoxin biosynthesis. In this study, the entire sxtG transcripts from Alexandrium fundyense CCMP1719 and Alexandrium minutum CCMP113 were amplified and sequenced. The transcripts contained typical dinoflagellate spliced leader sequences and eukaryotic poly(A) tails. In addition, partial sxtG transcript fragments were amplified from four additional Alexandrium species and Gymnodinium catenatum. The phylogenetic inference of dinoflagellate sxtG, congruent with sxtA, revealed a bacterial origin. However, it is not known if sxtG was acquired independently of sxtA. Amplification and sequencing of the corresponding genomic sxtG region revealed noncanonical introns. These introns show a high interspecies and low intraspecies variance, suggesting multiple independent acquisitions and losses. Unlike sxtA, sxtG was also amplified from Alexandrium species not known to synthesize saxitoxin. However, amplification was not observed for 22 non-saxitoxin-producing dinoflagellate species other than those of the genus Alexandrium or G. catenatum. This result strengthens our hypothesis that saxitoxin synthesis has been secondarily lost in conjunction with sxtA for some descendant species.

• Murray, Shauna A.; Wiese, Maria; Neilan, Brett A.; Orr, Russell; Salas, Miguel de & Brett, Steve [Show all 7 contributors for this article] (2012). A reinvestigation of saxitoxin production and sxtA in the 'non-toxic' Alexandrium tamarense Group V clade. Harmful Algae. ISSN 1568-9883. 18, p. 96–104. doi: 10.1016/j.hal.2012.05.001. Full text in Research Archive
• Dittami, Simon; Riisberg, Ingvild; John, Uwe; Orr, Russell; Jakobsen, Kjetill Sigurd & Edvardsen, Bente (2012). Analysis of Expressed Sequence Tags from the Marine Microalga Pseudochattonella farcimen (Dictyochophyceae). Protist. ISSN 1434-4610. 163(1), p. 143–161. doi: 10.1016/j.protis.2011.07.004. Full text in Research Archive
• Orr, Russell; Murray, Shauna A.; Stüken, Anke; Rhodes, Lesley & Jakobsen, Kjetill Sigurd (2012). When Naked Became Armored: An Eight-Gene Phylogeny Reveals Monophyletic Origin of Theca in Dinoflagellates. PLOS ONE. 7(11). doi: 10.1371/journal.pone.0050004. Full text in Research Archive Show summary

  The dinoflagellates are a diverse lineage of microbial eukaryotes. Dinoflagellate monophyly and their position within the group Alveolata are well established. However, phylogenetic relationships between dinoflagellate orders remain unresolved. To date, only a limited number of dinoflagellate studies have used a broad taxon sample with more than two concatenated markers. This lack of resolution makes it difficult to determine the evolution of major phenotypic characters such as morphological features or toxin production e.g. saxitoxin. Here we present an improved dinoflagellate phylogeny, based on eight genes, with the broadest taxon sampling to date. Fifty-five sequences for eight phylogenetic markers from nuclear and mitochondrial regions were amplified from 13 species, four orders, and concatenated phylogenetic inferences were conducted with orthologous sequences. Phylogenetic resolution is increased with addition of support for the deepest branches, though can be improved yet further. We show for the first time that the characteristic dinoflagellate thecal plates, cellulosic material that is present within the sub-cuticular alveoli, appears to have had a single origin. In addition, the monophyly of most dinoflagellate orders is confirmed: the Dinophysiales, the Gonyaulacales, the Prorocentrales, the Suessiales, and the Syndiniales. Our improved phylogeny, along with results of PCR to detect the sxtA gene in various lineages, allows us to suggest that this gene was probably acquired separately in Gymnodinium and the common ancestor of Alexandrium and Pyrodinium and subsequently lost in some descendent species of Alexandrium.

• Stüken, Anke Corinna; Orr, Russell; Kellmann, Ralf; Murray, Shauna A.; Neilan, Brett A. & Jakobsen, Kjetill Sigurd (2011). Discovery of Nuclear-Encoded Genes for the Neurotoxin Saxitoxin in Dinoflagellates. PLOS ONE. 6(5). doi: 10.1371/journal.pone.0020096. Full text in Research Archive Show summary

  Saxitoxin is a potent neurotoxin that occurs in aquatic environments worldwide. Ingestion of vector species can lead to paralytic shellfish poisoning, a severe human illness that may lead to paralysis and death. In freshwaters, the toxin is produced by prokaryotic cyanobacteria; in marine waters, it is associated with eukaryotic dinoflagellates. However, several studies suggest that saxitoxin is not produced by dinoflagellates themselves, but by co-cultured bacteria. Here, we show that genes required for saxitoxin synthesis are encoded in the nuclear genomes of dinoflagellates. We sequenced .1.26106 mRNA transcripts from the two saxitoxin-producing dinoflagellate strains Alexandrium fundyense CCMP1719 and A. minutum CCMP113 using high-throughput sequencing technology. In addition, we used in silico transcriptome analyses, RACE, qPCR and conventional PCR coupled with Sanger sequencing. These approaches successfully identified genes required for saxitoxin-synthesis in the two transcriptomes. We focused on sxtA, the unique starting gene of saxitoxin synthesis, and show that the dinoflagellate transcripts of sxtA have the same domain structure as the cyanobacterial sxtA genes. But, in contrast to the bacterial homologs, the dinoflagellate transcripts are monocistronic, have a higher GC content, occur in multiple copies, contain typical dinoflagellate spliced-leader sequences and eukaryotic polyA-tails. Further, we investigated 28 saxitoxin-producing and non-producing dinoflagellate strains from six different genera for the presence of genomic sxtA homologs. Our results show very good agreement between the presence of sxtA and saxitoxin-synthesis, except in three strains of A. tamarense, for which we amplified sxtA, but did not detect the toxin. Our work opens for possibilities to develop molecular tools to detect saxitoxin-producing dinoflagellates in the environment.

• Orr, Russell; Stüken, Anke; Rundberget, Thomas; Eikrem, Wenche & Jakobsen, Kjetill Sigurd (2011). Improved phylogenetic resolution of toxic and non-toxic Alexandrium strains using a concatenated rDNA approach. Harmful Algae. ISSN 1568-9883. 10(6), p. 676–688. doi: 10.1016/j.hal.2011.05.003. Full text in Research Archive
• Kellmann, Ralf; Stüken, Anke; Orr, Russell J. S.; Svendsen, Helene M. & Jakobsen, Kjetill S. (2010). Biosynthesis and Molecular Genetics of Polyketides in Marine Dinoflagellates. Marine Drugs. 8(4), p. 1011–1048. doi: 10.3390/md8041011. Full text in Research Archive
• Kumar, Surendra; Skjæveland, Åsmund; Orr, Russell; Enger, Pål; Ruden, Torgeir Andersen & Mevik, Bjørn-Helge [Show all 9 contributors for this article] (2009). AIR: A batch-oriented web program package for construction of supermatrices ready for phylogenomic analyses. BMC Bioinformatics. 10. doi: 10.1186/1471-2105-10-357. Full text in Research Archive Show summary

  Background: Large multigene sequence alignments have over recent years been increasingly employed for phylogenomic reconstruction of the eukaryote tree of life. Such supermatrices of sequence data are preferred over single gene alignments as they contain vastly more information about ancient sequence characteristics, and are thus more suitable for resolving deeply diverging relationships. However, as alignments are expanded, increasingly numbers of sites with misleading phylogenetic information are also added. Therefore, a major goal in phylogenomic analyses is to maximize the ratio of information to noise; this can be achieved by the reduction of fast evolving sites. Results: Here we present a batch-oriented web-based program package, named AIR that allows 1) transformation of several single genes to one multigene alignment, 2) identification of evolutionary rates in multigene alignments and 3) removal of fast evolving sites. These three processes can be done with the programs AIR-Appender, AIR-Identifier, and AIR-Remover (AIR), which can be used independently or in a semi-automated pipeline. AIR produces user-friendly output files with filtered and non-filtered alignments where residues are colored according to their evolutionary rates. Other bioinformatics applications linked to the AIR package are available at the Bioportal (www.bioportal.uio.no), University of Oslo; together these greatly improve the flexibility, efficiency and quality of phylogenomic analyses. Conclusions: The AIR program package allows for efficient creation of multigene alignments and better assessment of evolutionary rates in sequence alignments. Removing fast evolving sites with the AIR programs has been employed in several recent phylogenomic analyses resulting in improved phylogenetic resolution and increased statistical support for branching patterns among the early diverging eukaryotes.

• Minge, Marianne Aastebøl; Silberman, Jeffrey; Orr, Russell; Cavalier-Smith, Thomas; Shalchian-Tabrizi, Kamran & Burki, Fabien [Show all 8 contributors for this article] (2009). Evolutionary position of breviate amoebae and the primary eukaryote divergence. Proceedings of the Royal Society of London. Biological Sciences. ISSN 0962-8452. 276(1657), p. 597–604. doi: 10.1098/rspb.2008.1358. Full text in Research Archive
• Riisberg, Ingvild; Orr, Russell; Kluge, Ragnhild; Shalchian-Tabrizi, Kamran; Bowers, HA & Vishwanath, Patil [Show all 8 contributors for this article] (2009). Seven Gene Phylogeny of Heterokonts. Protist. ISSN 1434-4610. 160(2), p. 191–204. doi: 10.1016/j.protis.2008.11.004. Full text in Research Archive
• Shalchian-Tabrizi, Kamran; Minge, Marianne Aastebøl; Espelund, Mari; Orr, Russell; Ruden, Torgeir Andersen & Jakobsen, Kjetill Sigurd [Show all 7 contributors for this article] (2008). Multigene Phylogeny of Choanozoa and the Origin of Animals. PLOS ONE. 3(5). Full text in Research Archive

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• Orr, Russell (2017). In Silico Prediction of Ligand-Binding Sites of Plant Receptor Kinases Using Conservation Mapping. Plant Receptor Kinases: Methods and Protocols. Humana Press. ISBN 9781493970636. 196 p. Full text in Research Archive

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• Bøifot, Kari Oline; Orr, Russell; Brynildsrud, Ola Brønstad; Skogan, Gunnar & Dybwad, Marius (2024). Spatiotemporal stability of the air microbiome: Implications for simulation of bioaerosol backgrounds in aerosol test chambers. Full text in Research Archive
• Orr, Russell John Scott; Zhao, Sen; Klaveness, Dag; Yabuki, Akinori; Ikeda, Keiji & Watanabe, Makoto M. [Show all 7 contributors for this article] (2018). Correction to: Enigmatic Diphyllatea eukaryotes: culturing and targeted PacBio RS amplicon sequencing reveals a higher order taxonomic diversity and global distribution. BMC Evolutionary Biology. 18(1). doi: 10.1186/s12862-018-1233-y. Full text in Research Archive
• Orr, Russell (2017). Genome dynamics in early eukaryote evolution, progress rapport! Full text in Research Archive
• Orr, Russell (2017). Genome Dynamics in early eukaryote evolution an update! Full text in Research Archive
• Orr, Russell (2017). Deep Genome Initiative. Full text in Research Archive
• Orr, Russell; Rombauts, S; Peer, Yves Van De & Shalchian-Tabrizi, Kamran (2017). Erratum to "Draft Genome Sequences of Two Unclassified Bacteria, Sphingomonas sp. Strains IBVSS1 and IBVSS2, Isolated from Environmental Samples" [Genome Announc., 2017, 5 (34):e00894-17.] Doi: 10.1128/genomeA.00894-17. Microbiology Resource Announcements (MRA). 5(41). doi: 10.1128/genomeA.01175-17. Full text in Research Archive
• Orr, Russell; Rombauts, Stephane; Peer, Yves Van de & Shalchian-Tabrizi, Kamran (2017). Erratum: "Draft genome sequences of two unclassified Chitinophagaceae bacteria, IBVUCB1 and IBVUCB2, isolated from environmental samples" [Genome Announc, 5, 33, (2017), (e00787-17)] DOI:10.1128/genomeA.00787-17. Microbiology Resource Announcements (MRA). 5(41:e01152-17), p. 1–1. doi: 10.1128/genomeA.01152-17. Full text in Research Archive
• Orr, Russell; Zhao, Sen; Yabuki, Akinori & Shalchian-Tabrizi, Kamran (2016). PacBio sequencing reveals the diversity and ecology of a deeply diverging eukaryote lineage. Full text in Research Archive
• Enevoldsen, Emily; Boeve, Jeroen; Orr, Russell; Waeschenbach, Andrea & Liow, Lee Hsiang (2016). Advancing bryozoan phylogenetics: mitochondrial and nuclear genes. Full text in Research Archive
• Orr, Russell (2016). Genome dynamics in early eukaryotic evolution. Importance of enigmatic lineages. Full text in Research Archive
• Orr, Russell (2016). PacBio sequencing reveals the diversity and ecology of a deeply diverging eukaryote lineage. Full text in Research Archive
• Orr, Russell (2016). Genome dynamics in early eukaryotic evolution. Importance of enigmatic lineages. Full text in Research Archive
• Orr, Russell (2015). Genome dynamics in early eukaryotic evolution. Importance of enigmatic lineages. Full text in Research Archive
• Orr, Russell (2015). Genome dynamics in early eukaryotic evolution. Importance of enigmatic lineages. Full text in Research Archive
• Orr, Russell (2014). Genome dynamics in early eukaryotic evolution: importance of enigmatic lineages. Full text in Research Archive Show summary

  The origin of the eukaryotic cell from its bacterial ancestor is probably the most complex transition in evolution. Understanding the mechanisms of, and reasons for this major evolutionary transition is of fundamental importance for both cellular and evolutionary biology. To reconstruct the origin and evolution of the eukaryote cell one needs to study the changes that have occurred to an organisms hereditary information (genome) over time; from the most primitive to the most modern organisms. Recent improvements to the eukaryote tree of life have divided organisms it into a small number of so-called supergroups. These supergroups encompass the majority of living eukaryotes but there are still some enigmatic species that place external to these known groupings. Some of these species represent our earliest ancestors, and as such, are of major importance to understanding how the eukaryotic cell has evolved over time. Projects that map eukaryotic genomes are yet to study a species outside the known supergroups. Though, such a genome will give insight and resolution into how eukaryotes have evolved from a bacterial ancestor toward advanced eukaryotes. The overall objective of this project is therefore to explore the dynamics of genome changes that have occurred during evolution. This will be investigated by mapping the genomes from numerous enigmatic species that fall outside of the known supergroups. This information will then be compared with that of other eukaryotic organisms that place within the know groupings. The project builds on recent developments in techniques used for the extraction of genome information and comparison thereof, to focus on fundamental questions about the origin and evolution of eukaryotes. The project can therefore have significant bearing on central evolutionary issues and further our understanding of the developments that have occurred during eukaryotic evolution. The project will increase general understanding of processes that have form

• Orr, Russell (2014). Genome dynamics in early eukaryotic evolution: importance of enigmatic lineages. Full text in Research Archive
• Orr, Russell (2014). Genome dynamics in early eukaryotic evolution: importance of enigmatic lineages. Full text in Research Archive
• Enevoldsen, Emily; Liow, Lee Hsiang; Voje, Kjetil L.; Orr, Russell; Shalchian-Tabrizi, Kamran & Krabberød, Anders Kristian (2014). Macroevolution through molecular and morphological lenses: a history of microporellids. Full text in Research Archive
• Stüken, Anke; Figueroa, Rosa; Orr, Russell & Jakobsen, Kjetill Sigurd (2012). Is sxt gene copy number related to saxitoxin synthesis? Full text in Research Archive
• Stüken, Anke; Orr, Russell; Kellmann, Ralf; Murray, Shauna A.; Neilan, Brett A. & Jakobsen, Kjetill Sigurd (2011). Discovery of nucelar-encoded genes for the neurotoxin saxitoxin in dinoflagellates. Full text in Research Archive
• Stüken, Anke; Orr, Russell; Kellmann, Ralf; Murray, Shauna A.; Neilan, Brett A. & Jakobsen, Kjetill Sigurd (2011). Discovery of nucelar-encoded genes for the neurotoxin saxitoxin in dinoflagellates. Full text in Research Archive
• Stüken, Anke; Orr, Russell; Kellmann, Ralf; Murray, Shauna A.; Mihali, Troco Kaan & Neilan, Brett A. [Show all 7 contributors for this article] (2010). Saxitoxin gene identified in dinoflagellates. Full text in Research Archive
• Orr, Russell; Stüken, Anke; Rundberget, Thomas; Eikrem, Wenche & Jakobsen, Kjetill Sigurd (2010). Improved phylogenetic resolution of toxic and non-toxic Alexandrium strains using a concatenated rDNA approach. Full text in Research Archive
• Orr, Russell; Stüken, Anke; Rundberget, Thomas; Eikrem, Wenche & Jakobsen, Kjetill Sigurd (2010). Improved phylogenetic resolution of toxic and non-toxic Alexandrium strains using a concatenated rDNA approach. Full text in Research Archive
• Dittami, Simon; Riisberg, Ingvild; John, Uwe; Orr, Russell; Shalchian-Tabrizi, Kamran & Jakobsen, Kjetill Sigurd [Show all 7 contributors for this article] (2010). Analysis of expressed sequence tags from the ichtyotoxic dictyochophyte Pseudochattonella farcimen. Full text in Research Archive Show summary

  Pseudochattonella farcimen (Eikrem, Edvardsen, et Throndsen) is an ichthyotoxic alga within the Dictyochophyceae (Heterokonta), which has been shown to form blooms in Scandinavian waters every year since 1998. To improve our understanding of the biology of this alga and to facilitate future genomic studies, we report the sequencing and analysis of >10,000 expressed sequence tags (ESTs) corresponding to 8149 unique sequences from this species. A direct comparison with EST libraries from other heterokonts revealed several functional categories to be significantly overrepresented among the P. facimen ESTs, such as genes involved in cell communication, transporters, or genes targeted to cell organelles. Interestingly, P. farcimen ESTs also code for a high proportion (1.4%) of proteins related to fatty acid metabolism, including eight fatty acid desaturases and two phospholipase A2 genes. Three of the desaturases belong to a family of delta-4 desaturases, known so far only from haptophytes, where they catalyze the conversion of n3-docosapentaenoic (n3-DPA) acid to docosahexaenoic acid (DHA). These findings may partially explain the unusual fatty acid profiles observed in P. farcimen and are discussed both from an evolutionary point of view and in relation the ichthyotoxic effects of this alga.

• Minge, Marianne Aastebøl; Silberman, Jeffrey; Orr, Russell; Cavalier-Smith, Thomas; Shalchian-Tabrizi, Kamran & Burki, Fabien [Show all 8 contributors for this article] (2008). Breviata anathema - an unusual Amoebozoa. Full text in Research Archive
• Shalchian-Tabrizi, Kamran; Minge, Marianne Aastebøl; Espelund, Mari; Orr, Russell; Ruden, Torgeir A. & Jakobsen, Kjetill Sigurd [Show all 7 contributors for this article] (2008). The Choanozoan Ministeria vibrans: Multigene Phylogeny and the Origin of Animals. Full text in Research Archive Show summary

  Ministeria vibrans is a unicellular protozoan belonging to the phylum Choanozoa, the evolutionary closest related group to the animals. Ministeria is a minute bacteria-eating cell possessing slender radiating tentacles, that has recently been shown to be the most close relative to Capsaspora, another protozoan with thread-like (filose) tentacles. Forming the novel clade Filasterea, Ministeria/Capsaspora was shown to be sister to animals and choanoflagellates. Presumably, their last common ancestor evolved filose tentacles well before they were aggregated as a periciliary collar in the choanoflagellates. Several successive evolutionary innovations occurred among the unicellular closest relatives of the animals prior to the origin of multicellularity. We have analysed an EST library from this early branching choanozoan organism and have found many domains of key significance for animal cell biology. New domain combinations as well as domain duplications must have taken place along the path to multicellularity.

• Orr, Russell; Espelund, Mari; Kellmann, Ralf & Jakobsen, Kjetill Sigurd (2008). Evolution witihin the genus Alexandrium focusing on toxicity. Full text in Research Archive

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