EvolGenomics Journal Club: Transcriptomes of asexual stick insects provide insights into the consequences of asexuality

In the study of Bast et al., we will discuss genomic patterns associated with the lack of recombination in asexual stick insects such as levels of polymorphisms, biased gene conversion and the effectiveness of purifying selection.

 

Study

Marie Leys selected:

Consequences of asexuality in natural populations: insights from stick insects

Molecular Biology and Evolution (2018) 35: 1668 –1677

Abstract

  • Recombination is a fundamental process with significant impacts on genome evolution. Predicted consequences of the loss of recombination include a reduced effectiveness of selection, changes in the amount of neutral polymorphisms segregating in populations, and an arrest of GC-biased gene conversion. Although these consequences are empirically well documented for nonrecombining genome portions, it remains largely unknown if they extend to the whole genome scale in asexual organisms.
  • We identify the consequences of asexuality using de novo transcriptomes of five independently derived, obligately asexual lineages of stick insects, and their sexual sister-species.
  • We find strong evidence for higher rates of deleterious mutation accumulation, lower levels of segregating polymorphisms and arrested GC-biased gene conversion in asexuals as compared with sexuals.
  • Taken together, our study conclusively shows that predicted consequences of genome evolution under asexuality can indeed be found in natural populations.

Organizer

Marie Leys
Published Nov. 1, 2018 11:08 PM - Last modified Jan. 2, 2019 3:35 PM