Molecular cloning of DNA for inhibin alpha-subunit from equine ovary

cDNA encoding equine inhibin alpha-subunit precursor protein was isolated from an equine ovarian cDNA library. For screening, the DNA probe was amplified by the RT-PCR using primers designed based on the rat inhibin alpha-subunit cDNA sequence. Out of 1.2 x 10(5) plaques screened, 19 positive clones were isolated, and one of these clones (Eq-alpha-11) contained a complete open reading frame encoding 367 amino acids. The similarity of the deduced amino acid sequences of both equine inhibin alpha-subunit precursor protein and the mature protein were greater than 80% to those of other six mammalian species, including bovine, porcine, ovine, human, rat and mouse. Northern blot analysis revealed that a single major band at 1.5 kb was present in the RNA samples both from equine follicles and testes.