DISCRETE SPLICING ALTERNATIVES IN MESSENGER-RNA ENCODING THE EXTRACELLULAR DOMAIN OF THE TESTIS FSH RECEPTOR IN THE NORMAL AND HYPOGONADAL (HPG) MOUSE

The structure of RNA encoding the mouse testis FSH receptor was studied using reverse transcription and the polymerase chain reaction. Four major bands were observed by ethidium bromide staining and by hybridization to an FSH-receptor cDNA probe. The largest of these bands was the expected size (779 bp) while the other bands were spaced approximately 70 bp apart. Using alternative primers, each of the products was shown to contain exons 1, 9 and 10. Exons 2-8 in the FSH receptor gene are between 68 and 77 bp in size, suggesting that these multiple products arise by alternate splicing of the region encoding the extracellular domain of the receptor. A similar pattern of splicing was observed in cDNA from the testes of hypogonadal mice, showing that this alternative splicing pattern is not gonadotrophin-dependent.