DIFFERENTIAL EXPRESSION OF THE PROTOONCOGENES C-ABL AND C-MOS IN DEVELOPING MOUSE GERM-CELLS

C-abl and c-mos, two proto-oncogenes with unique patterns of expression in gonadal tissues, were examined by in situ hybridization with respect to their expression in the germ line. C-abl transcripts were observed to be most abundant in late round spermatids and elongating spermatids. C-mos transcripts were also expressed in round spermatids, but at much reduced levels compared to the levels of c-abl. C-abl mRNAs were also detected in mouse oocytes which have entered the growth phase. This temporal specificity of accumulation of c-abl transcripts was similar to that observed for c-mos, which also accumulates in growing and fully grown oocytes (follicle stages 4- 6). Quantitative evaluation suggested that c-abl mRNA levels in oocytes are at least an order of magnitude lower than those of c-mos transcripts. © 1993 Academic Press, Inc.