Walter Salzburger

• Fog, Lily G.; Isari, Stamatina; Barnes, Jonathan E.; Patel, Jagdish Suresh; Marshall, N. Justin & Salzburger, Walter [Show all 8 contributors for this article] (2026). Deep-sea fish reveal an alternative developmental trajectory for vertebrate vision. Science Advances. 12(7), p. 1–10. doi: 10.1126/sciadv.adx2596. Full text in Research Archive
• Costa, Vincenzo A.; Ronco, Fabrizia Nina; Mifsud, Jonathon C.O.; Harvey, Erin; Salzburger, Walter & Holmes, Edward C. (2024). Host adaptive radiation is associated with rapid virus diversification and cross-species transmission in African cichlid fishes. Current Biology. ISSN 0960-9822. 34(6), p. 1247–1257.e3. doi: 10.1016/j.cub.2024.02.008. Full text in Research Archive Show summary

  Adaptive radiations are generated through a complex interplay of biotic and abiotic factors. Although adaptive radiations have been widely studied in the context of animal and plant evolution, little is known about how they impact the evolution of the viruses that infect these hosts, which in turn may provide insights into the drivers of cross-species transmission and hence disease emergence. We examined how the rapid adaptive radiation of the cichlid fishes of African Lake Tanganyika over the last 10 million years has shaped the diversity and evolution of the viruses they carry. Through metatranscriptomic analysis of 2,242 RNA sequencing libraries, we identified 121 vertebrate-associated viruses among various tissue types that fell into 13 RNA and 4 DNA virus groups. Host-switching was commonplace, particularly within the Astroviridae, Metahepadnavirus, Nackednavirus, Picornaviridae, and Hepacivirus groups, occurring more frequently than in other fish communities. A time-calibrated phylogeny revealed that hepacivirus diversification was not constant throughout the cichlid radiation but accelerated 2–3 million years ago, coinciding with a period of rapid cichlid diversification and niche packing in Lake Tanganyika, thereby providing more closely related hosts for viral infection. These data depict a dynamic virus ecosystem within the cichlids of Lake Tanganyika, characterized by rapid virus diversification and frequent host jumping, and likely reflecting their close phylogenetic relationships that lower the barriers to cross-species virus transmission.

• Haefeli, Anja; Schedel, Frederic D.B.; Ronco, Fabrizia Nina; Indermaur, Adrian & Salzburger, Walter (2024). Revision of the cichlid fish genus Gnathochromis (Teleostei: Cichlidae) from Lake Tanganyika with the description of a new genus Jabarichromis gen. nov. Zootaxa. ISSN 1175-5326. 5410(3), p. 434–450. doi: 10.11646/zootaxa.5410.3.10. Full text in Research Archive Show summary

  The cichlid species flock from Lake Tanganyika is a well-studied system for evolutionary biology research because its species assemblage shows a high degree of endemism and is a product of adaptive radiation. While our understanding of the evolutionary history of Lake Tanganyika cichlids has advanced tremendously over the past decades, their taxonomy received considerably less attention, despite numerous taxonomic misplacements (e.g., polyphyletic genera and species) that have been revealed by phylogenetic studies. One prominent example of a polyphyletic genus is Gnathochromis, which includes two distantly related species, belonging to two different tribes. To resolve this issue, here we present a taxonomic revision based on an extensive morphological dataset obtained from a comprehensive taxon sampling including 587 specimens from 63 taxa. We introduce a new monotypic genus, Jabarichromis gen. nov. for ‘Gnathochromis’ pfefferi, a member of the tribe Tropheini, thereby separating it from the type species of Gnathochromis, G. permaxillaris. As a result, the genus Gnathochromis, which belongs to the tribe Limnochromini, is rendered monophyletic. Further, we provide an additional character to distinguish the recently described genus Shuja, which also belongs to the Tropheini, from its former mostly riverine congeners.

• Omelchenko, Dmytro; Bitja-Nyom, Arnold Roger; Matschiner, Michael; Malinsky, Milan; Indermaur, Adrian & Salzburger, Walter [Show all 8 contributors for this article] (2024). Haemoglobin Gene Repertoire in Teleost and Cichlid Fishes Shaped by Gene Duplications and Genome Rearrangements. Molecular Ecology. ISSN 0962-1083. doi: 10.1111/mec.17559. Full text in Research Archive Show summary

  Haemoglobin is a key molecule for oxygen transport in vertebrates. It exhibits remarkable gene diversity in teleost fishes, reflecting adaptation to various aquatic environments. In this study, we present the dynamic evolution of haemoglobin subunit genes based on a comparison of high-quality genome assemblies of 24 vertebrate species, including 17 teleosts (of which six are cichlids). Our findings indicate that teleost genomes contain a range of haemoglobin genes, from as few as five in fugu to as many as 43 in salmon, with the latter being the largest repertoire found in vertebrates. We find evidence that the teleost ancestor had at least four Hbα and three or four Hbβ subunit genes, and that the current gene diversity emerged during teleost radiation, driven primarily by (tandem) gene duplications, genome compaction, and rearrangement dynamics. We provide insights into the genomic organisation of haemoglobin clusters in different teleost species. We further show that the evolution of paralogous rhbdf1 genes flanking both teleost clusters (LA and MN) supports the hypothesis for the origin of the LA cluster by rearrangement within teleosts, rather than by the teleost specific whole-genome duplication. We specifically focus on cichlid fishes, where adaptation to low oxygen environment plays role in species diversification. Our analysis of six cichlid genomes, including Pungu maclareni from the Barombi Mbo crater lake, for which we sequenced a representative genome, reveals 18–32 copies of the Hb genes, and elevated rates of non-synonymous substitutions compared to other teleosts. Overall, this work facilitates a deeper understanding of how haemoglobin genes contribute to the adaptive potential of teleosts.

• Barth, Julia Maria Isis; Handley, Scott A.; Kintzl, Daniel; Leonard, Guy; Malinsky, Milan & Matschiner, Michael [Show all 10 contributors for this article] (2023). The history and organization of the Workshop on Population and Speciation Genomics. Evolution: Education and Outreach. ISSN 1936-6426. 16(1). doi: 10.1186/s12052-023-00182-w. Full text in Research Archive Show summary

  With the advent of high-throughput genome sequencing, bioinformatics training has become essential for research in evolutionary biology and related fields. However, individual research groups are often not in the position to teach students about the most up-to-date methodology in the field. To fill this gap, extended bioinformatics courses have been developed by various institutions and provide intense training over the course of two or more weeks. Here, we describe our experience with the organization of a course in one of the longest-running extended bioinformatics series of workshops, the Evomics Workshop on Population and Speciation Genomics that takes place biennially in the UNESCO world heritage town of Český Krumlov, Czech Republic. We list the key ingredients that make this workshop successful in our view, explain the routine for workshop organization that we have optimized over the years, and describe the most important lessons that we have learned from it. We report the results of a survey conducted among past workshop participants that quantifies measures of effective teaching and provide examples of how the workshop setting has led to the cross-fertilisation of ideas and ultimately scientific progress. We expect that our account may be useful for other groups aiming to set up their own extended bioinformatics courses.

• Ricci, Virginie; Ronco, Fabrizia; Boileau, Nicolas & Salzburger, Walter (2023). Visual opsin gene expression evolution in the adaptive radiation of cichlid fishes of Lake Tanganyika. Science Advances. 9(36). doi: 10.1126/sciadv.adg6568. Full text in Research Archive
• Muschick, Moritz; Jemmi, Eliane; Lengacher, Nicholas; Hänsch, Stephanie; Wales, Nathan & Kishe, Mary A. [Show all 12 contributors for this article] (2023). Ancient DNA is preserved in fish fossils from tropical lake sediments. Molecular Ecology. ISSN 0962-1083. 32(22), p. 5913–5931. doi: 10.1111/mec.17159. Full text in Research Archive Show summary

  Abstract Tropical freshwater lakes are well known for their high biodiversity, and particularly the East African Great Lakes are renowned for their adaptive radiation of cichlid fishes. While comparative phylogenetic analyses of extant species flocks have revealed patterns and processes of their diversification, little is known about evolutionary trajectories within lineages, the impacts of environmental drivers, or the scope and nature of now‐extinct diversity. Time‐structured palaeodata from geologically young fossil records, such as fossil counts and particularly ancient DNA (aDNA) data, would help fill this large knowledge gap. High ambient temperatures can be detrimental to the preservation of DNA, but refined methodology now allows data generation even from very poorly preserved samples. Here, we show for the first time that fish fossils from tropical lake sediments yield endogenous aDNA. Despite generally low endogenous content and high sample dropout, the application of high‐throughput sequencing and, in some cases, sequence capture allowed taxonomic assignment and phylogenetic placement of 17% of analysed fish fossils to family or tribe level, including remains which are up to 2700 years old or weigh less than 1 mg. The relationship between aDNA degradation and the thermal age of samples is similar to that described for terrestrial samples from cold environments when adjusted for elevated temperature. Success rates and aDNA preservation differed between the investigated lakes Chala, Kivu and Victoria, possibly caused by differences in bottom water oxygenation. Our study demonstrates that the sediment records of tropical lakes can preserve genetic information on rapidly diversifying fish taxa over time scales of millennia.

• Bista, Iliana; Wood, Jonathan M. D.; Desvignes, Thomas; McCarthy, Shane A.; Matschiner, Michael & Ning, Zemin [Show all 21 contributors for this article] (2023). Genomics of cold adaptations in the Antarctic notothenioid fish radiation. Nature Communications. 14(1). doi: 10.1038/s41467-023-38567-6. Full text in Research Archive
• Ronco, Fabrizia; Matschiner, Michael; Böhne, Astrid; Boila, Anna; Büscher, Heinz H & Taher, Athimed El [Show all 12 contributors for this article] (2020). Drivers and dynamics of a massive adaptive radiation in cichlid fishes. Nature. ISSN 0028-0836. 589, p. 76–81. doi: 10.1038/s41586-020-2930-4. Full text in Research Archive Show summary

  Adaptive radiation is the likely source of much of the ecological and morphological diversity of life1,2,3,4. How adaptive radiations proceed and what determines their extent remains unclear in most cases1,4. Here we report the in-depth examination of the spectacular adaptive radiation of cichlid fishes in Lake Tanganyika. On the basis of whole-genome phylogenetic analyses, multivariate morphological measurements of three ecologically relevant trait complexes (body shape, upper oral jaw morphology and lower pharyngeal jaw shape), scoring of pigmentation patterns and approximations of the ecology of nearly all of the approximately 240 cichlid species endemic to Lake Tanganyika, we show that the radiation occurred within the confines of the lake and that morphological diversification proceeded in consecutive trait-specific pulses of rapid morphospace expansion. We provide empirical support for two theoretical predictions of how adaptive radiations proceed, the ‘early-burst’ scenario1,5 (for body shape) and the stages model1,6,7 (for all traits investigated). Through the analysis of two genomes per species and by taking advantage of the uneven distribution of species in subclades of the radiation, we further show that species richness scales positively with per-individual heterozygosity, but is not correlated with transposable element content, number of gene duplications or genome-wide levels of selection in coding sequences.

• Matschiner, Michael; Böhne, Astrid; Ronco, Fabrizia & Salzburger, Walter (2020). The genomic timeline of cichlid fish diversification across continents. Nature Communications. 11(1). doi: 10.1038/s41467-020-17827-9. Full text in Research Archive Show summary

  Cichlid fishes are celebrated for their vast taxonomic, phenotypic, and ecological diversity; however, a central aspect of their evolution — the timeline of their diversification — remains contentious. Here, we generate draft genome assemblies of 14 species representing the global cichlid diversity and integrate these into a new phylogenomic hypothesis of cichlid and teleost evolution that we time-calibrate with 58 re-evaluated fossil constraints and a new Bayesian model accounting for fossil-assignment uncertainty. Our results support cichlid diversification long after the breakup of the supercontinent Gondwana and lay the foundation for precise temporal reconstructions of the exceptional continental cichlid adaptive radiations.

• Musilova, Zuzana; Cortesi, Fabio; Matschiner, Michael; Davies, Wayne I. L.; Patel, Jagdish Suresh & Stieb, Sara M. [Show all 18 contributors for this article] (2019). Vision using multiple distinct rod opsins in deep-sea fishes. Science. ISSN 0036-8075. 364(6440), p. 588–592. doi: 10.1126/science.aav4632. Full text in Research Archive
• Malmstrøm, Martin; Britz, Ralf; Matschiner, Michael; Tørresen, Ole K.; Hadiaty, Renny Kurnia & Yaakob, Norsham [Show all 10 contributors for this article] (2018). The Most Developmentally Truncated Fishes Show Extensive Hox Gene Loss and Miniaturized Genomes. Genome Biology and Evolution (GBE). 10(4), p. 1088–1103. doi: 10.1093/gbe/evy058. Full text in Research Archive Show summary

  The world’s smallest fishes belong to the genus Paedocypris. These miniature fishes are endemic to an extreme habitat: the peat swamp forests in Southeast Asia, characterized by highly acidic blackwater. This threatened habitat is home to a large array of fishes, including a number of miniaturized but also developmentally truncated species. Especially the genus Paedocypris is characterized by profound, organism-wide developmental truncation, resulting in sexually mature individuals of <8 mm in length with a larval phenotype. Here, we report on evolutionary simplification in the genomes of two species of the dwarf minnow genus Paedocypris using whole-genome sequencing. The two species feature unprecedented Hox gene loss and genome reduction in association with their massive developmental truncation. We also show how other genes involved in the development of musculature, nervous system, and skeleton have been lost in Paedocypris, mirroring its highly progenetic phenotype. Further, our analyses suggest two mechanisms responsible for the genome streamlining in Paedocypris in relation to other Cypriniformes: severe intron shortening and reduced repeat content. As the first report on the genomic sequence of a vertebrate species with organism-wide developmental truncation, the results of our work enhance our understanding of genome evolution and how genotypes are translated to phenotypes. In addition, as a naturally simplified system closely related to zebrafish, Paedocypris provides novel insights into vertebrate development.

• Meyer, Britta S.; Hablützel, Pascal I.; Roose, Anna K.; Hofmann, Melinda J; Salzburger, Walter & Raeymaekers, Joost A. M. (2018). An exploration of the links between parasites, trophic ecology, morphology, and immunogenetics in the Lake Tanganyika cichlid radiation. Hydrobiologia. ISSN 0018-8158. 832(1), p. 1–19. doi: 10.1007/s10750-018-3798-2. Full text in Research Archive
• Stange, Madlen; Sanchez-Villagra, Marcelo R; Salzburger, Walter & Matschiner, Michael (2018). Bayesian divergence-time estimation with genome-wide single-nucleotide polymorphism data of sea catfishes (Ariidae) supports miocene closure of the Panamanian Isthmus. Systematic Biology. ISSN 1063-5157. 67(4), p. 681–699. doi: 10.1093/sysbio/syy006. Full text in Research Archive
• Baalsrud, Helle Tessand; Voje, Kjetil L.; Tørresen, Ole Kristian; Solbakken, Monica Hongrø; Matschiner, Michael & Malmstrøm, Martin [Show all 10 contributors for this article] (2017). Evolution of Hemoglobin Genes in Codfishes Influenced by Ocean Depth. Scientific Reports. 7, p. 1–10. doi: 10.1038/s41598-017-08286-2. Full text in Research Archive Show summary

  Understanding the genetic basis of adaptation is one of the main enigmas of evolutionary biology. Among vertebrates, hemoglobin has been well documented as a key trait for adaptation to different environments. Here, we investigate the role of hemoglobins in adaptation to ocean depth in the diverse teleost order Gadiformes, with species distributed at a wide range of depths varying in temperature, hydrostatic pressure and oxygen levels. Using genomic data we characterized the full hemoglobin (Hb) gene repertoire for subset of species within this lineage. We discovered a correlation between expanded numbers of Hb genes and ocean depth, with the highest numbers in species occupying shallower, epipelagic regions. Moreover, we demonstrate that the Hb genes have functionally diverged through diversifying selection. Our results suggest that the more variable environment in shallower water has led to selection for a larger Hb gene repertoire and that Hbs have a key role in adaptive processes in marine environments.

• Matschiner, Michael; Musilová, Zuzana; Barth, Julia Maria Isis; Starostová, Zuzana; Salzburger, Walter & Steel, Mike [Show all 7 contributors for this article] (2017). Bayesian phylogenetic estimation of clade ages supports trans-Atlantic dispersal of cichlid fishes. Systematic Biology. ISSN 1063-5157. 66(1), p. 3–22. doi: 10.1093/sysbio/syw076. Full text in Research Archive Show summary

  Divergence-time estimation based on molecular phylogenies and the fossil record has provided insights into fundamental questions of evolutionary biology. In Bayesian node dating, phylogenies are commonly time calibrated through the specification of calibration densities on nodes representing clades with known fossil occurrences. Unfortunately, the optimal shape of these calibration densities is usually unknown and they are therefore often chosen arbitrarily, which directly impacts the reliability of the resulting age estimates. As possible solutions to this problem, two non-exclusive alternative approaches have recently been developed, the “fossilized birth-death” model and “total-evidence dating”. While these approaches have been shown to perform well under certain conditions, they require including all (or a random subset) of the fossils of each clade in the analysis, rather than just relying on the oldest fossils of clades. In addition, both approaches assume that fossil records of different clades in the phylogeny are all the product of the same underlying fossil sampling rate, even though this rate has been shown to differ strongly between higher-level taxa. We here develop a flexible new approach to Bayesian age estimation that combines advantages of node dating and the fossilized birth-death model. In our new approach, calibration densities are defined on the basis of first fossil occurrences and sampling rate estimates that can be specified separately for all clades. We verify our approach with a large number of simulated datasets, and compare its performance to that of the fossilized birth-death model. We find that our approach produces reliable age estimates that are robust to model violation, on par with the fossilized birth-death model. By applying our approach to a large dataset including sequence data from over 1000 species of teleost fishes as well as 147 carefully selected fossil constraints, we recover a timeline of teleost diversification that is incompatible with previously assumed vicariant divergences of freshwater fishes. Our results instead provide strong evidence for trans-oceanic dispersal of cichlids and other groups of teleost fishes.

• Baalsrud, Helle Tessand; Tørresen, Ole Kristian; Solbakken, Monica Hongrø; Salzburger, Walter; Hanel, Reinhold & Jakobsen, Kjetill Sigurd [Show all 7 contributors for this article] (2017). De Novo Gene Evolution of Antifreeze Glycoproteins in Codfishes Revealed by Whole Genome Sequence Data. Molecular Biology and Evolution (MBE). ISSN 0737-4038. 35(3), p. 593–606. doi: 10.1093/molbev/msx311. Full text in Research Archive Show summary

  New genes can arise through duplication of a pre-existing gene or de novo from non-coding DNA, providing raw material for evolution of new functions in response to a changing environment. A prime example is the independent evolution of antifreeze glycoprotein genes (afgps) in the Arctic codfishes and Antarctic notothenioids to prevent freezing. However, the highly repetitive nature of these genes complicates studies of their organization. In notothenioids, afgps evolved from an extant gene, yet the evolutionary origin of afgps in codfishes is unknown. Here, we demonstrate that afgps in codfishes have evolved de novo from non-coding DNA 13–18 Ma, coinciding with the cooling of the Northern Hemisphere. Using whole-genome sequence data from several codfishes and notothenioids, we find higher copy number of afgp in species exposed to more severe freezing suggesting a gene dosage effect. Notably, antifreeze function is lost in one lineage of codfishes analogous to the afgp losses in non-Antarctic notothenioids. This indicates that selection can eliminate the antifreeze function when freezing is no longer imminent. In addition, we show that evolution of afgp-assisting antifreeze potentiating protein genes (afpps) in notothenioids coincides with origin and lineage-specific losses of afgp. The origin of afgps in codfishes is one of the first examples of an essential gene born from non-coding DNA in a non-model species. Our study underlines the power of comparative genomics to uncover past molecular signatures of genome evolution, and further highlights the impact of de novo gene origin in response to a changing selection regime.

• Malmstrøm, Martin; Matschiner, Michael; Tørresen, Ole Kristian; Star, Bastiaan; Snipen, Lars-Gustav & Hansen, Thomas F [Show all 13 contributors for this article] (2016). Evolution of the immune system influences speciation rates in teleost fishes. Nature Genetics. ISSN 1061-4036. 48(10), p. 1204–1210. doi: 10.1038/ng.3645. Full text in Research Archive Show summary

  Teleost fishes constitute the most species-rich vertebrate clade and exhibit extensive genetic and phenotypic variation, including diverse immune defense strategies. The genomic basis of a particularly aberrant strategy is exemplified by Atlantic cod, in which a loss of major histocompatibility complex (MHC) II functionality coincides with a marked expansion of MHC I genes. Through low-coverage genome sequencing (9–39×), assembly and comparative analyses for 66 teleost species, we show here that MHC II is missing in the entire Gadiformes lineage and thus was lost once in their common ancestor. In contrast, we find that MHC I gene expansions have occurred multiple times, both inside and outside this clade. Moreover, we identify an association between high MHC I copy number and elevated speciation rates using trait-dependent diversification models. Our results extend current understanding of the plasticity of the adaptive immune system and suggest an important role for immune-related genes in animal diversification.

• Cortesi, Fabio; Musilová, Zuzana; Stieb, Sara M.; Hart, Nathan S.; Siebeck, Ulrike E. & Cheney, Karen L. [Show all 8 contributors for this article] (2016). From crypsis to mimicry: Changes in colour and the configuration of the visual system during ontogenetic habitat transitions in a coral reef fish. Journal of Experimental Biology. ISSN 0022-0949. 219(16), p. 2545–2558. doi: 10.1242/jeb.139501. Full text in Research Archive
• Meyer, Britta S.; Matschiner, Michael & Salzburger, Walter (2016). Disentangling Incomplete Lineage Sorting and Introgression to Refine Species-Tree Estimates for Lake Tanganyika Cichlid Fishes. Systematic Biology. ISSN 1063-5157. 66(4), p. 531–550. doi: 10.1093/sysbio/syw069. Full text in Research Archive Show summary

  Adaptive radiation is thought to be responsible for the evolution of a great portion of the past and present diversity of life. Instances of adaptive radiation, characterized by the rapid emergence of an array of species as a consequence to their adaptation to distinct ecological niches, are important study systems in evolutionary biology. However, because of the rapid lineage formation in these groups, and occasional gene flow between the participating species, it is often difficult to reconstruct the phylogenetic history of species that underwent an adaptive radiation. In this study, we present a novel approach for species-tree estimation in rapidly diversifying lineages, where introgression is known to occur, and apply it to a multimarker data set containing up to 16 specimens per species for a set of 45 species of East African cichlid fishes (522 individuals in total), with a main focus on the cichlid species flock of Lake Tanganyika. We first identified, using age distributions of most recent common ancestors in individual gene trees, those lineages in our data set that show strong signatures of past introgression. This led us to formulate three hypotheses of introgression between different lineages of Tanganyika cichlids: the ancestor of Boulengerochromini (or of Boulengerochromini and Bathybatini) received genomic material from the derived H-lineage; the common ancestor of Cyprichromini and Perissodini experienced, in turn, introgression from Boulengerochromini and/or Bathybatini; and the Lake Tanganyika Haplochromini and closely related riverine lineages received genetic material from Cyphotilapiini. We then applied the multispecies coalescent model to estimate the species tree of Lake Tanganyika cichlids, but excluded the lineages involved in these introgression events, as the multispecies coalescent model does not incorporate introgression. This resulted in a robust species tree, in which the Lamprologini were placed as sister lineage to the H-lineage (including the Eretmodini), and we identify a series of rapid splitting events at the base of the H-lineage. Divergence ages estimated with the multispecies coalescent model were substantially younger than age estimates based on concatenation, and agree with the geological history of the Great Lakes of East Africa. Finally, we formally tested the three hypotheses of introgression using a likelihood framework, and find strong support for introgression between some of the cichlid tribes of Lake Tanganyika.

• Gante, Hugo F; Matschiner, Michael; Malmstrøm, Martin; Jakobsen, Kjetill Sigurd; Jentoft, Sissel & Salzburger, Walter (2016). Genomics of speciation and introgression in Princess cichlid fishes from Lake Tanganyika. Molecular Ecology. ISSN 0962-1083. 25(24), p. 6143–6161. doi: 10.1111/mec.13767. Full text in Research Archive Show summary

  How variation in the genome translates into biological diversity and new species originate has endured as the mystery of mysteries in evolutionary biology. African cichlid fishes are prime model systems to address speciation-related questions for their remarkable taxonomic and phenotypic diversity, and the possible role of gene flow in this process. Here, we capitalize on genome sequencing and phylogenomic analyses to address the relative impacts of incomplete lineage sorting, introgression and hybrid speciation in the Neolamprologus savoryi-complex (the ‘Princess cichlids’) from Lake Tanganyika. We present a time-calibrated species tree based on whole-genome sequences and provide strong evidence for incomplete lineage sorting in the early phases of diversification and multiple introgression events affecting different stages. Importantly, we find that the Neolamprologus chromosomes show centre-to-periphery biases in nucleotide diversity, sequence divergence, GC content, incomplete lineage sorting and rates of introgression, which are likely modulated by recombination density and linked selection. The detection of heterogeneous genomic landscapes has strong implications on the genomic mechanisms involved in speciation. Collinear chromosomal regions can be protected from gene flow and harbour incompatibility genes if they reside in lowly recombining regions, and coupling can evolve between nonphysically linked genomic regions (chromosome centres in particular). Simultaneously, higher recombination towards chromosome peripheries makes these more dynamic, evolvable regions where adaptation polymorphisms have a fertile ground. Hence, differences in genome architecture could explain the levels of taxonomic and phenotypic diversity seen in taxa with collinear genomes and might have contributed to the spectacular cichlid diversity observed today.

• Cortesi, Fabio; Musilováa, Zuzana; Stieb, Sara M.; Hart, Nathan S.; Siebeck, Ulrike E. & Malmstrøm, Martin [Show all 12 contributors for this article] (2015). Ancestral duplications and highly dynamic opsin gene evolution in percomorph fishes. Proceedings of the National Academy of Sciences of the United States of America (PNAS). ISSN 0027-8424. 112(5), p. 1493–1498. doi: 10.1073/pnas.1417803112. Full text in Research Archive
• Baldo, Laura; Riera, Joan Lluis; Tooming-Klunderud, Ave; Alba, M. Mar & Salzburger, Walter (2015). Gut microbiota dynamics during dietary shift in eastern African cichlid fishes. PLOS ONE. 10(5). doi: 10.1371/journal.pone.0127462. Full text in Research Archive Show summary

  The gut microbiota structure reflects both a host phylogenetic history and a signature of adaptation to the host ecological, mainly trophic niches. African cichlid fishes, with their array of closely related species that underwent a rapid dietary niche radiation, offer a particularly interesting system to explore the relative contribution of these two factors in nature. Here we surveyed the host intra- and interspecific natural variation of the gut microbiota of five cichlid species from the monophyletic tribe Perissodini of lake Tanganyika, whose members transitioned from being zooplanktivorous to feeding primarily on fish scales. The outgroup riverine species Astatotilapia burtoni, largely omnivorous, was also included in the study. Fusobacteria, Firmicutes and Proteobacteria represented the dominant components in the gut microbiota of all 30 specimens analysed according to two distinct 16S rRNA markers. All members of the Perissodini tribe showed a homogenous pattern of microbial alpha and beta diversities, with no significant qualitative differences, despite changes in diet. The recent diet shift between zooplantkon- and scale-eaters simply reflects on a significant enrichment of Clostridium taxa in scale-eaters where they might be involved in the scale metabolism. Comparison with the omnivorous species A. burtoni suggests that, with increased host phylogenetic distance and/or increasing herbivory, the gut microbiota begins differentiating also at qualitative level. The cichlids show presence of a large conserved core of taxa and a small set of core OTUs (average 13–15%), remarkably stable also in captivity, and putatively favoured by both restricted microbial transmission among related hosts (putatively enhanced by mouthbrooding behavior) and common host constraints. This study sets the basis for a future large-scale investigation of the gut microbiota of cichlids and its adaptation in the process of the host adaptive radiation.

• Colombo, Marco; Damerau, Malte; Hanel, Reinhold; Salzburger, Walter & Matschiner, Michael (2015). Diversity and disparity through time in the adaptive radiation of Antarctic notothenioid fishes. Evolutionary Biology. ISSN 0071-3260. 28, p. 376–394. doi: 10.1111/jeb.12570. Full text in Research Archive
• Meyer, Britta S.; Matschiner, Michael & Salzburger, Walter (2015). A tribal level phylogeny of Lake Tanganyika cichlid fishes based on a genomic multi-marker approach. Molecular Phylogenetics and Evolution. ISSN 1055-7903. 83, p. 56–71. doi: 10.1016/j.ympev.2014.10.009. Full text in Research Archive
• Matschiner, Michael; Colombo, Marco; Damerau, Malte; Ceballos, Santiago; Hanel, Reinhold & Salzburger, Walter (2015). The Adaptive Radiation of Notothenioid Fishes in the Waters of Antarctica. In Riesch, Rüdiger; Tobler, Michael & Plath, Martin (Ed.), Extremophile Fishes. Springer. ISSN 9783319133621. p. 35–57. doi: 10.1007/978-3-319-13362-1_3. Full text in Research Archive

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• Matschiner, Michael & Salzburger, Walter (2019). Evolution: Genomic Signatures of Mimicry and Mimicry of Genomic Signatures. Current Biology. ISSN 0960-9822. 29, p. R363–R365. doi: 10.1016/j.cub.2019.04.015. Full text in Research Archive
• Baalsrud, Helle Tessand; Tørresen, Ole Kristian; Malmstrøm, Martin; Salzburger, Walter; Jakobsen, Kjetill Sigurd & Jentoft, Sissel (2015). The hemoglobin repertoire in the order of Gadiformes linked to depth adaptation. Full text in Research Archive

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