sex chromosome

These findings shed light on the evolution of sex chromosomes and inform understanding of diseases related to genes on these chromosomes in both apes and humans.

Whereas in humans it is males who carry a sex-specific chromosome, the Y chromosome, in birds it is females who have a sex chromosome, the W chromosome.

The genome consists of 2.9 billion base pairs, which form 23 autosomal chromosomes, and X and Y sex chromosomes.

Female birds have two different sex chromosomes, designated W and Z, while males have two Z chromosomes.

The team found some species with minor changes, mainly involving fusions of small autosomes5 and the sex chromosome.