Evidence for an H-Y crossreactive antigen in invertebrates

A sex specific antigen which crossreacts with the mammalian H-Y antigen has been identified on the cell surface of hemocytes from the lobster (Homarus americanus) and the gonadal cells of three insect species. The hemocytes from the male lobster, the testicular cells from the male beetle (P. cornutus), and the ovarian cells from two Orthopteran species (L. maderae and D. punctata) specifically absorbed H-Y antibodies. The specificity of H-Y antibody absorptions by cells from only one sex, suggest that an ancestral H-Y-like antigen may be present in invertebrates which could be engaged in sexual (cellular) recognition events.