Convergent consequences of parthenogenesis on stick insect genomes

Kamil Jaron (1, 2, 3) , Darren Parker (1, 2) , Yoann Anselmetti (4, 5) , Patrick Tran Van (1, 2) , Jens Bast (1, 6) , Zoé Dumas (1) , Emeric Figuet (4) , Clémentine François (7) , Keith Hayward (1, 2) , Victor Rossier (1, 2) , Paul Simion (4, 8) , Marc Robinson-Rechavi (1, 2) , Nicolas Galtier (4) , Tanja Schwander (1)

1 UNIL - Université de Lausanne = University of Lausanne
2 SIB - Swiss Institute of Bioinformatics [Genève]
3 Edin. - University of Edinburgh
4 UMR ISEM - Institut des Sciences de l'Evolution de Montpellier
5 CoBIUS, Department of Computer Science
6 University of Cologne
7 E3S - Équipe 3 - Écologie, Évolution, Écosystemes Souterrains
8 UNamur - Université de Namur [Namur]

The shift from sexual reproduction to parthenogenesis has occurred repeatedly in animals, but how the loss of sex affects genome evolution remains poorly understood. We generated reference genomes for five independently evolved parthenogenetic species in the stick insect genus Timema and their closest sexual relatives. Using these references and population genomic data, we show that parthenogenesis results in an extreme reduction of heterozygosity and often leads to genetically uniform populations. We also find evidence for less effective positive selection in parthenogenetic species, suggesting that sex is ubiquitous in natural populations because it facilitates fast rates of adaptation. Parthenogenetic species did not show increased transposable element (TE) accumulation, likely because there is little TE activity in the genus. By using replicated sexual-parthenogenetic comparisons, our study reveals how the absence of sex affects genome evolution in natural populations, providing empirical support for the negative consequences of parthenogenesis as predicted by theory.

Domaines: Biodiversité et Ecologie

Kamil Jaron, Darren Parker, Yoann Anselmetti, Patrick Tran Van, Jens Bast, et al.. Convergent consequences of parthenogenesis on stick insect genomes. Science Advances , 2022, 8 (8), ⟨10.1126/sciadv.abg3842⟩. ⟨hal-03592524⟩