Polymorphisms of PRLR and FOLR1 genes and association with milk production traits in goats.

We investigated the polymorphisms of PRLR and FOLR1 genes in Xinong Saanen, Guanzhong, and Boer goat breeds by DNA sequencing and PCR-RFLP. Two novel SNPs were identified: KC109741: g.62130C>T in the 3ꞌ-UTR of goat gene PRLR, and KC136296: g.7884A>C in exon 3 of goat gene FOLR1. In the three goat breeds, the polymorphism information content was 0.20-0.27 at the g.62130C>T locus. At the g.7884A>C locus, it was 0.36 in Boer goats. The three goat breeds were in Hardy-Weinberg disequilibrium at the g.62130C>T locus. The g.62130C>T SNP was found to be significantly associated with milk production traits in Xinong Saanen and Guanzhong breeds. These results are consistent with the regulatory function of PRLR in mammary gland development, milk secretion, and expression of milk protein genes; they extend the spectrum of genetic variation of the goat PRLR gene, which could be useful for breeding programs.

Molecular cloning and characterization of KISS1 promoter and effect of KISS1 gene mutations on litter size in the goat.

Kisspeptins, the product of the KISS1 gene, play an essential role in the regulation of reproductive functions, acting primarily at the hypothalamic level of the gonadotropic axis. We detected polymorphisms of the goat KISS1 gene in 723 individuals from three goat breeds (Xinong Saanen, Guanzhong, and Boer) by DNA pooling, PCR-RFLP, and DNA sequencing methods. We cloned the promoter sequence of this gene and found it to share high similarity with that of the bovine KISS1 promoter. Six TATA boxes were found in the goat KISS1 promoter region. Two novel SNPs (g.2124T>A and g.2270C>T) were identified in the intron 1 of the KISS1 gene of all three goat breeds. The three goat breeds were in Hardy-Weinberg disequilibrium at g.2124T>A and g.2270C>T loci. The g.2124T>A and g.2270C>T loci were closely linked in the three goat breeds (r2 > 0.33). The g.2124T>A and g.2270C>T SNPs were significantly associated with litter size, and the C1 female goats had a larger litter size than did those with the other genotypes. These results extend the spectrum of genetic variation of the goat KISS1 gene, which contributes to our knowledge of goat genetic resources for breeding programs.

Transcriptional activity of an ovarian-specific promoter from rat in dairy goat granulosa cells.

Ovarian-specific promoter 1 (OSP-1) is a retrovirus-like element isolated from the complementary DNA library of rat that has been thought to be specifically expressed in ovary. To exploit this promoter in dairy goat ovary granulosa cells (GCs), OSP-1 from rat was used to construct the reporter vector pOSP-1-EGFP, in which egfp coding for enhanced green fluorescent protein (EGFP) was used as a reporter to examine the activity of OSP-1 in GCs. EGFP was successfully expressed in dairy goat GCs transfected with pOSP-1-EGFP. Reverse transcriptase-polymerase chain reaction analysis confirmed the tissue-specific transcription of EGFP messenger RNA in dairy goat GCs transfected with pOSP-1-EGFP. We concluded that OSP-1 promoter from rat can specifically drive foreign gene expression in dairy goat GCs. Thus, we obtained a tissue-specific regulation element and provided a potential tool for the research of regulation and development of the ovary in dairy goats.

A new approach for cloning hLIF cDNA from genomic DNA isolated from the oral mucous membrane.

Complementary DNA (cDNA) is valuable for investigating protein structure and function in the study of life science, but it is difficult to obtain by traditional reverse transcription. We employed a novel strategy to clone human leukemia inhibitory factor (hLIF) gene cDNA from genomic DNA, which was directly isolated from the mucous membrane of mouth. The hLIF sequence, which is 609 bp long and is composed of three exons, can be acquired within a few hours by amplifying each exon and splicing all of them using overlap-PCR. This new approach developed is simple, time- and cost-effective, without RNA preparation or cDNA synthesis, and is not limited to the specific tissues for a particular gene and the expression level of the gene.