Ykromosoom

Ykromosoom, commonly referred to as the Y chromosome, is one of the two sex chromosomes in humans and many other species with the XY sex-determination system. In mammals, males typically possess one Y chromosome paired with one X, while females have two X chromosomes. The Y chromosome carries genes that influence male development and spermatogenesis, and it is inherited from father to son with relatively little recombination.

Anatomy and gene content: The human Y chromosome is considerably smaller than the X chromosome and contains a distinct structure comprising a non-recombining region (the male-specific region of the Y, MSY) and two short pseudoautosomal regions at its tips that can recombine with the X. The MSY houses most of the Y-linked genes, including the SRY gene, which initiates male sex-determination during embryonic development. Other Y-linked genes involved in testis function include the DAZ gene family, RBMY, KDM5D, UTY, EIF1AY, and USP9Y, though the total number of genes is small compared with the X chromosome.

Functions and significance: Beyond sex determination, Y-linked genes contribute to spermatogenesis and male fertility in many species. Deletions or mutations in Y-linked regions can lead to infertility, notably Y-chromosome microdeletions in humans. The Y chromosome is inherited patrilineally and is widely used in studies of paternal ancestry, population history, and forensically in some contexts, using Y-chromosome markers. Evolutionarily, the Y has undergone substantial gene loss and sequence decay relative to the X, but retains essential functions in reproduction and a small, rapidly evolving gene repertoire.