Synthesis and turnover of sulfogalactoglycerolipid, a membrane lipid, during spermatogenesis

The synthesis and turnover of sulfogalactoglycerolipid (SGG) were studied by in vivo labelling of SGG with 35S. The loss of [35S]SGG from the testes and its appearance in the vas deferens plus epididymis were followed with time. DNA was labelled by administration of [3H]thymidine and the behavior of the two isotopes was compared. The results demonstrate that SGG snythesis occurs only in very early spermatocytes and that, once made, the compound does not turn over. The SGG is lost from the testes when germinal cells die or mature into spermatozoa.