DEVELOPMENTALLY-REGULATED EXPRESSION OF A MOUSE GERM-CELL NUCLEAR ANTIGEN EXAMINED FROM EMBRYONIC DAY-11 TO ADULT IN MALE AND FEMALE MICE

A rat IgM monoclonal antibody has been developed which recognizes a mo use germ cell nuclear antigen (GCNA1). GCNA1 is present in prospermato gonia (gonocytes) in males and in oogonia and oocytes of females withi n the gonadal ridge from Embryonic Day 11.5 onward, but rarely in prim ordial germ cells prior to their arrival at the gonadal ridge. Immunol ocalization demonstrates that GCNA1 is abundant in nuclei of spermatog onia and early spermatocytes, but decreases during subsequent spermato cyte and round spermatid development, and is not detected beyond step 10 elongating spermatids. The antigen is similar to 80-110 kDa on immu noblots of isolated pachytene spermatocytes and round spermatids. Howe ver, GCNA1 appears to be absent from sperm in the epididymis and vas d eferens, Sertoli cells, TM3 cells (Leydig-like) and TM4 cells (Sertoli -like), lung, liver, kidney, spleen, heart, skin, brain, epididymis, a nd ovary. GCNA1 is present in prepuberal male mice (Days 2-14) in all stages of prespermatogonial and spermatogonial development. It is also present in oocytes of neonatal females until Postpartum Day 12. GCNA1 is first lost from oocytes in the medulla of the ovary as they arrest at the dictyate stage and gain a layer of granulosa cells. In additio n, the antigen is present in moderate amounts in F9 embryonal carcinom a cells and SCC-PSA1 pluripotent teratocarcinoma cells. Thus, GCNA1 se rves as a common marker of the germ cell lineage in male and female mi ce after primordial germ cells arrive in the gonadal ridge until they reach the diplotene/dictyate stage of the first meiotic division. (C) 1994 Academic Press, Inc.