Association between copy number variation of SERPINA3-1 gene and growth traits in Chinese cattle.

Serpin peptidase inhibitor, clade A (alpha-1 antiproteinase, antitrypsin), member 3 (SERPINA3) belongs to the serine protease inhibitor family A subtype, and contains 8 genes from SERPINA3-1 to SERPINA3-8. Although the regulatory effects of these 8 genes have been revealed one by one in recent years, the related effects of SERPINA3-1 gene on cattle growth is still unclear. This study used quantitative Real time PCR (qPCR) to detect the type of copy number variation (CNV) of SERPINA3-1 gene in a total of 542 Chinese cattle, and expression of SERPINA3-1 gene in different tissues of Qinchuan cattles (adult) on mRNA level. Then association analysis was conducted between the detection results and cattle growth traits. The results showed that the Duplication type in SERPINA3-1 gene performed better on the growth traits and the CNV was significantly correlated with multiple growth traits (p < 0.05). In addition, SERPINA3-1 gene has different expression conditions in different tissues, results showed that SERPINA3-1 gene has a low expression in muscle. In conclusion, we speculate that the SERPINA3-1 gene can be used as a molecular marker and the result of this study could be a basic material for candidate functional genes for beef cattle growth and development.

In order to detect the gene expression diversification of the SERPINA3-1 gene, blood samples were collected from five Chinese cattle breeds, we detected related signal and made an associated analyze with cattle growth traits. We determined the copy number variation distribution of the SERPINA3-1 gene in cattle populations and found that the SERPINA3-1 gene has a certain promoting effect on the growth and development of Chinese cattle. For example, Pinan cattle with Duplication type copy number have a better performance on growth traits. This study has enriched the candidate genes of Chinese cattle molecular breeding and provided basic data for Chinese cattle breeding.

Copy number variation of MYLK4 gene and its growth traits of Capra hircus (goat).

Copy number variation (CNV) is a form of genetic variation caused by genome rearrangement, with abnormal fragments ranging from 50 bp to Mb. And, CNV is closely related to disease, growth and reproductive shape of livestock. As a member of myosin light chain kinase (MYLK) family with serine/threonine specificity, MYLK4 belongs to an enzyme encoded by MYLK4 gene. Although MYLK4 is a recognized kinase, its function has yet to be revealed in subsequent studies. This study aims to analyze CNV and genetic effects of MYLK4 gene in goats. We used qPCR to detect CNV of MYLK4 gene in African Nubian goat (n = 32), Guizhou black goat (n = 196) and Guizhou white goat (n = 95), respectively, and correlated CNV data of MYLK4 gene with goat growth traits in Chinese goats. The results showed that the effect of MYLK4 gene CNV on body weight, body length and body height of goats had significantly different (p < 0.05, Q < 0.05), in which CNV showed better growth traits in type of deletion. Therefore, CNV of MYLK4 gene can be used as a molecular marker for assisted selection of goat growth traits, which provides a theoretical basis for the genetic improvement of goat breeds in China.

A novel SNP of PLAG1 gene and its association with growth traits in Chinese cattle.

Genetic polymorphism has great influences on the improvement of cattle traits. The polymorphism of the same gene family will greatly change the growth traits of cattle, such as the pleomorphic adenoma gene (PLAG) family. Many studies have shown that the PLAG family proteins are the transcription regulators of nuclear protein, which mainly regulates the expression of many important genes in the body. In cattle, single nucleotide polymorphisms (SNPs) within or near the PLAG1 gene is associated with economic traits of height in cattle. Here we investigate a SNPs of bovine PLAG1 in 646 cattle from five breeds. We found three different genotypes by using cleaved amplification polymorphism sequence-tagged sites (CAPs), includes some significant differences in body height, chest circumference and other shapes (P < 0.05), also we found that the TT genotype had no advantage in body shape. These results indicate that the selection of PLAG1 gene could be used to ensure the breeding direction for growth traits of the beef cattle.

DNA methylation status of CRABP2 promoter down-regulates its expression.

As an important epigenetic modification DNA methylation is catalyzed by DNA methylation transferases (DNMTs) and occurs mainly in CpG islands. DNA methylation plays an important role in regulates gene expression, cell differentiation, genetic imprinting and tumor therapy. Retinoic acid-binding proteins (RAC) is vital for the absorption, transport, metabolism and maintenance of homeostasis of retinoic acid, which in turn regulates the differentiation and proliferation of cells by regulating the transcription of many target genes, therefore, these proteins influence differentiation and proliferation of adipocytes and muscle fibroblasts. Thus, cellular retinoic acid binding protein 2 (CRABP2) may be a candidate gene which affects beef quality, yield and fat deposition. The aim of this study was to evaluate the expression and the methylation pattern on the differentially methylated region (DMR) of the promoter of CRABP2. The DNA methylation pattern was tested by bisulfite sequencing polymerase chain reaction (BSP), the quantitative real-time PCR (qPCR) was used to analysis the expression of CRABP2 gene. The results showed that the DNA methylation level was higher in purebred cattle breed than that in hybrid cattle breeds which was negative correlation with the expression of the gen. These results indicate that the methylation status of the CRABP2 DMR can regulate mRNA expression. What's more, there are different methylation and expression patterns in different breeds and tissues which may influence the phenotype, and the results may be a useful parameter to investigate the function of CRABP2 in muscle and fat developmental in Chinese cattle.