DETECTION OF C-MOS RELATED PRODUCTS IN THE DOGFISH (SCYLIORHINUS-CANICULA) TESTIS

The objective of the present paper was to do a comparative study to as sess somatic versus germ cell localization of c-mos products in the te stis. In mouse and amphibian oocytes, c-mos activity is necessary for meiotic maturation. Lack of c-mos expression has been reported in soma tic cells of male and female gonads while transcripts have been found in germ cells of testis and ovary. Using a v-mos probe, we report here the detection of a c-mos-related transcript (1.7 kb) in the dogfish S cyliorhinus canicula testis. Western blot analysis detects two protein s of 106 and 32 kDa. A specific immunostaining was exclusively localiz ed in the interstitial tissue while the germinal compartment was compl etely negative. In conclusion, our results indicate for the first time the presence of c-mos products in an elasmobranch species and, moreov er, their presence in somatic testicular cells rather than germ cells. Therefore, this finding in an ancient vertebrate indicates that c-mos activity does not have a direct universal role in the regulation of s permatogenesis.