Spermatogenesis-associated changes of fucosylated glycolipids in murine testis

By targeted deletion of either the FUT1- or FUT2-gene for α1,2-fucosyltransferase, expression of FGM1 and FGA1, in murine testis was revealed to be sustained through unique interchangeability of the genes, indicating their significant roles for spermatogenesis. Accordingly, we examined the amounts of FGM1 and FGA1 in the testes of mice at 1-42 days after birth in comparison to those of several glycolipids including seminolipid. Although Forssman antigen and GM1 were present in relatively constant amounts during the period examined, GM3, which was the major one at 1 day, quickly decreased during development and had completely disappeared at 4 weeks. The following glycolipids were expressed in stage-specific manners, FGM1 for primary spermatocytes at 1 week, a seminolipid for secondary spermatocytes at 2 weeks, and GM3 lactone and FGA1 for spermatids and spermatozoa at 3 weeks. In fact, immunohistochemical staining with anti-FGM1 and anti-FGA1 antibodies demonstrated that FGM1 and FGA1 were distributed in the spermatocytes, and the spermatids and spermatozoa, respectively, and FGA1, together with seminolipid, were the immunogenic markers of spermatozoa. Thus, the fucosylation of glycolipids is a spermatogenesis-associated event, which should occur even with use of either the FUT1- or FUT2-gene.