TY - JOUR

T1 - Haplotype divergence supports long-term asexuality in the oribatid mite Oppiella nova

AU - Brandt, Alexander

AU - Tran Van, Patrick

AU - Bluhm, Christian

AU - Anselmetti, Yoann

AU - Dumas, Zoé

AU - Figuet, Emeric

AU - François, Clémentine M

AU - Galtier, Nicolas

AU - Heimburger, Bastian

AU - Jaron, Kamil S

AU - Labédan, Marjorie

AU - Maraun, Mark

AU - Parker, Darren J

AU - Robinson-Rechavi, Marc

AU - Schaefer, Ina

AU - Simion, Paul

AU - Scheu, Stefan

AU - Schwander, Tanja

AU - Bast, Jens

N1 - Copyright © 2021 the Author(s). Published by PNAS.

PY - 2021/9/21

Y1 - 2021/9/21

N2 - Sex strongly impacts genome evolution via recombination and segregation. In the absence of these processes, haplotypes within lineages of diploid organisms are predicted to accumulate mutations independently of each other and diverge over time. This so-called "Meselson effect" is regarded as a strong indicator of the long-term evolution under obligate asexuality. Here, we present genomic and transcriptomic data of three populations of the asexual oribatid mite species Oppiella nova and its sexual relative Oppiella subpectinata We document strikingly different patterns of haplotype divergence between the two species, strongly supporting Meselson effect-like evolution and long-term asexuality in O. nova: I) variation within individuals exceeds variation between populations in O. nova but vice versa in O. subpectinata; II) two O. nova sublineages feature a high proportion of lineage-specific heterozygous single-nucleotide polymorphisms (SNPs), indicating that haplotypes continued to diverge after lineage separation; III) the deepest split in gene trees generally separates the two haplotypes in O. nova, but populations in O. subpectinata; and IV) the topologies of the two haplotype trees match each other. Our findings provide positive evidence for the absence of canonical sex over evolutionary time in O. nova and suggest that asexual oribatid mites can escape the dead-end fate usually associated with asexual lineages.

AB - Sex strongly impacts genome evolution via recombination and segregation. In the absence of these processes, haplotypes within lineages of diploid organisms are predicted to accumulate mutations independently of each other and diverge over time. This so-called "Meselson effect" is regarded as a strong indicator of the long-term evolution under obligate asexuality. Here, we present genomic and transcriptomic data of three populations of the asexual oribatid mite species Oppiella nova and its sexual relative Oppiella subpectinata We document strikingly different patterns of haplotype divergence between the two species, strongly supporting Meselson effect-like evolution and long-term asexuality in O. nova: I) variation within individuals exceeds variation between populations in O. nova but vice versa in O. subpectinata; II) two O. nova sublineages feature a high proportion of lineage-specific heterozygous single-nucleotide polymorphisms (SNPs), indicating that haplotypes continued to diverge after lineage separation; III) the deepest split in gene trees generally separates the two haplotypes in O. nova, but populations in O. subpectinata; and IV) the topologies of the two haplotype trees match each other. Our findings provide positive evidence for the absence of canonical sex over evolutionary time in O. nova and suggest that asexual oribatid mites can escape the dead-end fate usually associated with asexual lineages.

KW - Acari/genetics

KW - Animals

KW - Evolution, Molecular

KW - Genetic Variation/genetics

KW - Haplotypes/genetics

KW - Mites/genetics

KW - Phylogeny

KW - Reproduction, Asexual/genetics

U2 - 10.1073/pnas.2101485118

DO - 10.1073/pnas.2101485118

M3 - Article

C2 - 34535550

VL - 118

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 38

ER -