Cloning and characterization of the rat alpha-inhibin gene

The gene for the rat glycoprotein hormone alpha-inhibin has been cloned and characterized. The entire gene was found to be contained within a 5.5 kilobase EcoRI fragment. It is composed of two exons separated by a 1.5 kb intron. Primer extension and S1 nuclease analysis showed that the major transcription initiation site in the ovary was 77 bp from the start of translation. The promoter region of the gene did not contain a conventional TATA box but instead a number of GA rich repeated sequences were found to be present. Other potential regulatory elements found included a repeating purine-pyrimidine tract (TG)28, cAMP and phorbol ester response elements and a putative glucocorticoid response element. Southern blot analysis of rat genomic DNA indicated that there is a single gene for alpha-inhibin in the rat.