Genomic origins and evolution of neo-sex chromosomes in Pacific Island birds.

ABSTRACT: The standard model of sex chromosome evolution is based on ancient XY or ZW systems. Young neo-sex chromosomes that form via the translocation of autosomal material to preexisting sex chromosomes provide materials to study early events in sex chromosome evolution. Neo-sex chromosomes are taxonomically widespread but, until recently, appeared to be rare in female-heterogametic taxa, including birds. Here, we report on the comparative evolutionary genomics of newly discovered neo-Z and neo-W sex chromosomes in two Pacific Island birds, the honeyeater species, Myzomela tristrami and M. cardinalis. Our results show that 19 to 21 Mya, ~85% of chr5, an autosome, translocated to the pseudoautosomal region (PAR) of an ancestral sex chromosome (Z or W) and rapidly recombined on

SUBMITTER: Muirhead CA 

PROVIDER: S-EPMC12337287 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature