MULTIPLE TRANSCRIPTION START SITES FOR THE GNRH GENE IN RHESUS AND CYNOMOLGUS MONKEYS - A NONHUMAN PRIMATE MODEL FOR STUDYING GNRH GENE-REGULATION

In humans, transcription of the gonadotropin-releasing hormone (GnRH) gene can be initiated at two transcription start sites to produce diff erent GnRH mRNAs. The upstream transcription start site is used only i n reproductive tissues and tumors. To determine if a similar pattern o f GnRH gene expression exists in non-human primates, we cloned GnRH cD NA from rhesus monkey hypothalamic RNA using reverse transcriptase-pol ymerase chain reaction (RT-PCR) and the 5' flanking region of the monk ey GnRH gene by PCR. A 96% similarity between monkey and human GnRH cD NA was found with 94% similarity in the upstream promoter region. An u pstream transcriptional start site, was identified in cynomolgus monke y testicular mRNA, 504 base pairs upstream from the hypothalamic site, which was different from that identified in the human GnRH gene. Vari ous cynomolgus monkey reproductive tissues were found to utilize this upstream transcriptional start site. In contrast, no evidence was foun d for the use of upstream transcriptional start sites in rat testis or placenta, suggesting that the reproductive tissue specificity of the upstream transcription start site may be a primate specific feature.