Genomics of an avian neo-sex chromosome reveals the evolutionary dynamics of recombination suppression and sex-linked genes
Genomics of an avian neo-sex chromosome reveals the evolutionary dynamics of recombination suppression and sex-linked genes
ABSTRACT How the avian sex chromosomes first evolved from autosomes remains elusive as 100 million years (Myr) of divergence and degeneration obscure their evolutionary history. Sylvioidea songbirds is an emerging model for understanding avian sex chromosome evolution because a unique chromosome fusion event ～24 Myr ago has formed enlarged “neo-sex chromosomes” consisting of an added (new) and an ancestral (old) part. Here, we report the female genome (ZW) of one Sylvioidea species, the great reed warbler (Acrocephalus arundinaceus). We confirm that the added region has been translocated to both Z and W, and show that the added-W part has been heavily reorganised within itself and with the ancestral-W. Next, we show that recombination between Z and W continued after the fusion event, and that recombination suppression took ～10 Myr to be completed and arose locally and non-linearly along the sex chromosomes. This pattern is inconsistent with that of large inversions and instead suggests gradual and mosaic recombination suppression. We find that the added-W mirrors the ancestral-W in terms of repeat accumulation, loss of genetic variation, and gene degeneration. Lastly, we show that genes being maintained on W are slowly evolving and dosage sensitive, and that highly conserved genes across broad taxonomic groups, regardless of sex-linkage, evolve slower on both Z and W. This study reveals complex expansion of recombination suppression along avian sex chromosomes, and that the evolutionary trajectory of sex-linked genes is highly predictable and governed partly by sex-linkage per se, partly by their functional properties.
Kutschera Verena E.、Lundberg Max、Bunikis Ignas、Tarka Maja、Hasselquist Dennis、Proux-W¨|ra Estelle、Strandh Maria、Sigeman Hanna、Zhang Hongkai、Hansson Bengt、Nystedt Bj?rn、Westerdahl Helena、Soler Lucile、Ponnikas Suvi
Department of Biochemistry and Biophysics, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Stockholm UniversityDepartment of Biology, Lund University, Ecology BuildingUppsala Genome Center, Science for Life Laboratory, Dept. of Immunology, Genetics and Pathology, Uppsala UniversityDepartment of Biology, Lund University, Ecology BuildingDepartment of Biology, Lund University, Ecology BuildingDepartment of Biochemistry and Biophysics, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Stockholm UniversityDepartment of Biology, Lund University, Ecology BuildingDepartment of Biology, Lund University, Ecology BuildingDepartment of Biology, Lund University, Ecology BuildingDepartment of Biology, Lund University, Ecology BuildingDepartment of Cell and Molecular Biology, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Uppsala UniversityDepartment of Biology, Lund University, Ecology BuildingDepartment of Medical Biochemistry and Microbiology, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Uppsala UniversityDepartment of Biology, Lund University, Ecology Building
遗传学动物学分子生物学
sex chromosomeneo-sex chromosomerecombinationdegenerationvertebratebird
Kutschera Verena E.,Lundberg Max,Bunikis Ignas,Tarka Maja,Hasselquist Dennis,Proux-W¨|ra Estelle,Strandh Maria,Sigeman Hanna,Zhang Hongkai,Hansson Bengt,Nystedt Bj?rn,Westerdahl Helena,Soler Lucile,Ponnikas Suvi.Genomics of an avian neo-sex chromosome reveals the evolutionary dynamics of recombination suppression and sex-linked genes[EB/OL].(2025-03-28)[2025-06-12].https://www.biorxiv.org/content/10.1101/2020.09.25.314088.点此复制
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