Multi-layered dosage compensation of the avian Z chromosome by increased transcriptional burst frequency and elevated translational rates.

ABSTRACT: Sex-chromosome dosage poses a challenge for heterogametic species in maintaining the proper balance of gene products across chromosomes in each sex. While therian mammals (XX/XY system) achieve near-perfect balance of X-chromosome mRNAs through X-upregulation and X-inactivation, birds (ZW/ZZ system) have been found to lack efficient compensation at RNA level, challenging the necessity of resolving major gene-dosage asymmetries in avian cells. Through comprehensive allele-resolved multiome analyses, we examine dosage compensation in female (ZW), male (ZZ), and rare intersex (ZZW) chicken. Our data reveal that females upregulate their single Z chromosome through increased transcriptional burst frequency, mirroring mammalian X upregulation. Z-protein levels are further balanced in females thr

SUBMITTER: Papanicolaou N 

PROVIDER: S-EPMC12518621 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature