Characterization of the Luteinizing Hormone Beta (LH-β) Subunit Gene in the Goat

Abstract

Background: Luteinizing hormone (LH) plays a critical role in ovulation and maintenance of pregnancy in female and gamete production in male during fertile phase of life. Physiological disturbance of this hormone leads to conditions like delayed ovulation, anovulation, cystic ovarian disease and lack of sexual desire in male. Since, there had been no report of molecular characterization of β-subunit of luteinizing hormone (LH) of Indian goat, the present study aimed to clone and characterize genomic DNA encoding LHβ subunit.Methods: Genomic DNA was extracted from goat blood and amplified using specific LHβ gene primers. After cloning and transformation, plasmids were isolated from randomly selected white colonies. Presence of insert was confirmed by restriction enzyme digestion of plasmids. After confirmation by PCR, plasmids were sent for DNA sequencing. Result: Analysis of sequence revealed an insert of 1006 bp size as expected. Comparison of nucleotide sequence revealed the cloned gene to be is LHβ encoding 141 amino acids. It showed 97.3 and 91.7% similarity with sheep and cattle respectively. Inferred amino acid sequence showed absolute similarity (100%) with sheep and buffalo. The common and essential features such as twelve cysteine molecules, a single potential N-glycosylation site, the CAGY region and another tetrapeptide CGPC are all found in the goat sequence too.