Identification of Polymorphisms in the Enhancer Region of the Bovine Prolactin Gene

摘要

Prolactin (PRL) stimulates mammary development and promotes the formation and action of the corpus luteum during the female reproductive cycle in some mammals. The compounds associated with fescue toxicosis depress the levels of PRL in cattle, reducemilk yield, and lower reproductive efficiency. Studies have shown that administering other hormones may alleviate these symptoms by raising PRL levels in Box indicus (Brahman) but not Bos taunts (Angus) cattle. This research project attempts to locate polymorphisms in the enhancer region of the PRL gene and correlate this to Brahman and Angus parentages. Two polymorphisms were found at positions -1161 and -1286. Genomic DNA from 73 Angus, Brahman, and Angus/Brahman crossed cows was analyzed for these single nucleotide polymorphisms (SNPs). Both SNPs showed allelic frequency variation between the Brahman and Angus populations. On the polymorphism at -1286, Brahmans were the predominant carriers with fewer carriers in the Angus population. This SNP has an allele frequency of 0.507. The polymorphism at -1161 showed even more variation in that the Brahmans appear to be the only carriers of the allele, with a frequency of 0.137. Results demonstrate that the enhancer region of the bovine prolactin gene hassequence differences that appear to be associated with Brahman cattle.