MIP-1-ALPHA IS A REGULATOR OF MITOTIC AND MEIOTIC DNA-SYNTHESIS DURING SPERMATOGENESIS

To find out whether macrophage inflammatory protein-1 alpha (MIP-1 alp ha) has a role in the regulation of germ cell development, we studied its effects on spermatogenic stage-specific DNA synthesis in vitro. MI P-1 alpha increased the DNA synthesis of primitive type A(2-4) spermat ogonia and of premeiotic cells, whereas the DNA synthesis of more diff erentiated intermediate and type B spermatogonia was inhibited when cu ltured in the presence of MIP-1 alpha. An antibody against MIP-1 alpha cross-reacted with a protein of 15 kDa from every spermatogenic stage of rat seminiferous epithelium. Immunohistochemical studies with the same antibody revealed a complex pattern of MIP-1 alpha localization b oth in primitive and advanced spermatogenic cells. These observations suggest that MIP-1 alpha is a local regulator of mitotic and meiotic D NA synthesis.