Expression of follicle-stimulating hormone receptor mRNA in rat testes and Sertoli cells

In order to better understand the role of FSH in reproduction, we have studied the expression of its receptor in the male rat. A DNA probe for the rat FSH receptor (FSHR) was generated by the polymerase chain reaction, and a partial genomic clone was isolated. Northern blot analysis revealed two transcripts for the FSHR, a 2.6-kilobase (kb) transcript, which is the predominant mRNA, and a 4.5-kb transcript. The two transcripts were specific to the testis and ovary, and in the testis, the expression of the mRNA appeared to be primarily in the Sertoli cells. Northern blot analysis showed the presence of FSHR mRNA in testes from rats ranging in age from 10-60 days as well as in Sertoli cells cultured from 20-day-old and adult animals. FSHR mRNA levels in testes synchronized to specific stages of the seminiferous epithelium were shown by Northern blot analysis to be highest in stages XIII-II and to decrease to a minimum at stages VII-VIII. The levels of FSHR mRNA underwent more than a 3-fold change during the cycle of the seminiferous epithelium.