The serologically detected H-Y antigen revisited

Area of Science:

• Immunogenetics
• Mammalian Genetics
• Reproductive Biology

Background:

• H-Y antigen is a male-associated phenotype identified through immunological assays.
• Its role in sex determination was initially proposed but later disproven, with SRY now recognized as the primary testis-determining factor (TDF).

Purpose of the Study:

• To investigate the genetic basis and immunological detection of H-Y antigen.
• To clarify the relationship between H-Y antigen, sex determination, and male-specific functions.

Main Methods:

• Immunological methods: graft rejection, T-cell mediated cytotoxicity, and antiserum cytotoxicity.
• Genetic analysis using specific T-cell clones to identify Y-linked genes.
• Serological detection of H-Y antigen in mammals and non-mammalian vertebrates.

Main Results:

• Two mouse Y-linked genes (Smcy, Uty) coding for H-Y epitopes were identified; SMCY is also on the human Y chromosome.
• Anti-H-Y antisera detect both membrane-bound and soluble antigens, potentially distinct from T-cell detected peptides.
• Soluble H-Y antigen may be anti-Müllerian hormone in mammals; H-Y antigen is associated with the heterogametic sex in non-mammalian vertebrates.

Conclusions:

• H-Y antigens are genetically heterogeneous but likely involved in male-specific functions in mammals.
• H-Y antigen may play a role in heterogametic sex differentiation in non-mammalian vertebrates.
• SRY, not H-Y antigen, is the principal testis-determining factor in mammals.