REFINEMENT OF THE DIFFERENTIATED PHENOTYPE OF THE SPERMATOGENIC CELL-LINE GC-2SPD(TS)

A transformed spermatogenic cell line GC-2spd(ts), recently reported t o express a protein marker of spermiogenesis, was tested for the prese nce of several mRNAs encoded by genes transcribed specifically in the testis and at precise stages of spermatogenesis. Northern blotting and reverse-transcriptase polymerase chain reaction techniques showed tha t mRNAs for the stage-specific marker proteins LDH-C-4 (preleptotene), acrosin (premeiotic), protamine-2 (postmeiotic), and SP-10 (postmeiot ic round spermatid stage) were not detected in CC-2spd(ts) cells. Flow cytometric analysis of GC-2spd(ts) failed to detect a peak indicative of the presence of haploid chromosomes. Furthermore, the HS-63 monocl onal antibody, employed in an earlier report to demonstrate putative p roacrosomal granules, failed to recognize the SP-10 protein in extract s of human or mouse sperm or in CC-2spd(ts) cells and instead recogniz ed proteins of different masses. In view of interest in this line as a model for analyzing molecular events of spermatogenesis, this refinem ent of the GC-2spd(ts) phenotype may aid others considering these cell s for studies of terminal stages of sperm differentiation.