Repeated Evolution of Asexuality Involves Convergent Gene Expression Changes

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DOI

  • Darren J Parker
    University of LausanneSwiss Institute of Bioinformatics, Geneva
  • Jens Bast
    University of Lausanne
  • Kirsten Jalvingh
    University of Lausanne
  • Zoé Dumas
    University of Lausanne
  • Marc Robinson-Rechavi
    University of Lausanne
  • Tanja Schwander
    University of Lausanne

Asexual reproduction has evolved repeatedly from sexual ancestors across a wide range of taxa. Whereas the costs and benefits associated with asexuality have received considerable attention, the molecular changes underpinning the evolution of asexual reproduction remain relatively unexplored. In particular, it is completely unknown whether the repeated evolution of asexual phenotypes involves similar molecular changes, as previous studies have focused on changes occurring in single lineages. Here, we investigate the extent of convergent gene expression changes across five independent transitions to asexuality in stick insects. We compared gene expression of asexual females to females of close sexual relatives in whole-bodies, reproductive tracts, and legs. We identified a striking amount of convergent gene expression change (up to 8% of genes), greatly exceeding that expected by chance. Convergent changes were also tissue-specific, and most likely driven by selection for functional changes. Genes showing convergent changes in the reproductive tract were associated with meiotic spindle formation and centrosome organization. These genes are particularly interesting as they can influence the production of unreduced eggs, a key barrier to asexual reproduction. Changes in legs and whole-bodies were likely involved in female sexual trait decay, with enrichment in terms such as sperm-storage and pigmentation. By identifying changes occurring across multiple independent transitions to asexuality, our results provide a rare insight into the molecular basis of asexual phenotypes and suggest that the evolutionary path to asexuality is highly constrained, requiring repeated changes to the same key genes.

Keywords

  • Animals, Biological Evolution, Female, Gene Expression, Insecta/genetics, Reproduction, Asexual/genetics
Original languageEnglish
Pages (from-to)350-364
Number of pages15
JournalMolecular Biology and Evolution
Volume36
Issue number2
Early online date16 Nov 2018
DOIs
Publication statusPublished - 1 Feb 2019
Externally publishedYes
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