Dictionary of Human Evolution and Biology

  • -id > 9:3

H-Y Antigen

Any of several minor histocompatibility epitopes (or inducers) that map to HSA Yq; candidate genes are SMCY, DFFRY and UTY. One or more of the antigen(s) are reportedly identical to the Mullerian-inhibiting hormone. Homogametic individuals (males, in humans) produce the antigen; heterogametic individuals (females) have a homologous antagonistic locus (H-Y regulator, SMCX/DFFRX/ UTX) on the portion of their Xp22.3 chromosomes that does not undergo heteropycnosis. An autosomal H-Y structural gene has been reported, and maps to the MHC on 6p. SMCY is highly conserved and has been located on the Y chromosome of most mammalian species for 120 my. Because males experience more germ cell divisions per generation than females, it is possible that the Y chromosome evolves faster than the X chromosome; SMCY evolves 1.8 times faster than SMCX and has accumulated three times more mutations in the most recent 28,000 year period.

Full-Text Search Entries