Association between leptin gene polymorphisms and growth traits in Limousin cattle

A total of 129 Limousin calves were used to investigate how leptin gene polymorphisms affect growth traits, such as body weight, average daily gain, wither height, sacrum height and chest girth in beef cattle. Two single nucleotide polymorphisms (SNPs) were genotyped, including the Sau3AI polymorphism in intron 2 and the A59V polymorphism in exon 3. The genotype and allele frequencies for each SNP and the haplotype frequencies for both SNPs were estimated in the studied herd. Statistical analysis revealed that the A59V polymorphism significantly affected the body weight at 210 days of age (P ≤ 0.01) and the average daily gain between 3 and 210 days of age (P ≤ 0.05) with T as a desirable allele. No associations were observed between the Sau3AI polymorphism and the growth traits mentioned above. However, the average daily gain between 3 and 210 days of age was significantly higher in the CT/CT haplotype animals compared with the CC/CC and CC/CT individuals. These results indicated that selection for the A59V TT animals might contribute to an improved body weight in Limousin cattle. The article is published in the original.     

Association between JY-1 gene polymorphisms and reproductive traits in beef cattle

Reproductive traits have a high economic value and it is interesting to include them in the selection objectives of an animal breeding program. These traits generally show low heritability and molecular markers may therefore be used in genetic evaluations to improve the accuracy of predictions. The JY-1 gene is expressed in the oocyte and it is associated with folliculogenesis and early embryo development. It has been suggested to affect reproductive traits. In this study, exons 1 and 2 of the JY-1 gene were studied in 385 Nellore females by PCR-sequencing. Seventeen polymorphisms were identified. After analysis of linkage disequilibrium, association tests were performed between eight SNPs and the occurrence of early pregnancy, age at first calving, days to calving, and reconception of primiparous heifers. Seven SNPs were significant for three traits. The most significant was chr29:12,999 T/A (p = 0.003) which was associated with the occurrence of early pregnancy. This SNP might be involved in protein translation inhibition since it affects the initial methionine codon. The JY-1, an oocyte specific gene, influences reproductive traits; further studies investigating other regions of the gene or other genes expressed in tissues of the female reproductive system would be interesting to be performed.     

郏县红牛DGAT2基因多态性与生长性状的相关性分析

利用PCR-RFLP技术对随机抽取的92头郏县红牛的DGAT2基因进行多态性分析。结果表明, DGAT2基因第6内含子的PCR扩增产物被限制性酶TaqⅠ酶切消化后表现多态性。经电泳检测后, 显出AA、AB两种不同基因型。该基因座处于Hardy-Weinberg平衡状态, 通过对郏县红牛DGAT2基因多态性与体重及体尺指标的方差分析显示：郏县红牛DGAT2基因不同基因型对郏县红牛体重和体长有显著影响(P<0.05), 而对其他体尺指标在统计学上无显著影响(P>0.05), 且初步认为AB基因型对选择有正向效应。     

A-FABP基因多态性与肉鸡生长和体组成性状的关联

为探讨A-FABP基因多态性对肉鸡生长和体组成性状的影响,文章选用肉鸡高、低脂双向选择品系第十世代肉仔鸡为实验材料,采用测序、PCR-RFLP、PCR-LP、DHPLC方法进行基因多态性检测和个体基因型分析,通过对8个SNPs进行连锁不平衡分析并选择5个标签SNPs构建单倍型,进而利用单位点和单倍型分别与鸡生长和体组成性状进行关联分析。结果表明,7个SNPs(除SNP 5以外)及单倍型同时对鸡肌胃重、肌胃率有显著影响(P<0.05),而对生长和其他体组成性状无显著影响(P>0.05)。鉴于不同物种A-FABP基因现有的功能研究均没有发现其对消化系统有重要作用,因此该基因是否为影响肉鸡肌胃重和肌胃率的主效基因还有待于进一步研究。     

Association between CSN3 and BCO2 gene polymorphisms and milk performance traits in the Czech Fleckvieh cattle breed

Daily milk, fat and protein yield and amount of somatic cells in cow milk are very important factors that influence milk performance traits. An association between polymorphisms in the kappa casein (CSN3) gene and milk production, composition and technical properties has been previously reported; however, this type of information is not available for the bovine β-carotene oxygenase 2 (BCO2) gene--the BCO2 gene has relationship with milk color and meat fat color, which is dependent on content of β-carotene. We analyzed these two genes and their relationship with milk performance traits (daily milk, fat and protein yield, somatic cell count, SCC) in one cattle population, Czech Fleckvieh (N = 152). All animals were milked twice a day and kept in the same environmental conditions. The Fleckvieh is a typical Czech cattle breed farming for milk and meat production. It is the most common breed in the Czech Republic. DNA was isolated from milk or from hairs. Genes were analyzed using PCR-RFLP, frequencies of alleles and genotypes were calculated and association analysis was performed using a GLM Procedure in SAS. Statistical analysis established that the CSN3 gene has no statistically significant influence on daily milk, fat and protein yield and SCC. Compared to other references this result can be explained by, e.g., small group of animals and different cattle breed. The BCO2 gene (genotypes AA and AG) shows a statistically significant relationship (P = 0.05) with daily milk, protein yield and SCC.     

Associations of polymorphism within the GHSR gene with growth traits in Nanyang cattle

GH secretagogue receptor (ghrelin receptor, GHSR) is known to be involved in the control of GH release by mediating the strong stimulatory effect of the endogenous ligand, ghrelin, on GH secretion. Associations between the GHSR gene polymorphism and the growth traits were revealed in Nanyang cattle. The mutations at nt456(G > A) and nt667(C > T) were complete linkage and located in exon 1 of the coding region of the GHSR gene. Least squares analysis revealed a significant statistical effect (P < 0.05) of the GHSR gene different genotypes on body weight and average daily gain at 6 months of age in Nanyang cattle. Individuals with GHSR-MM genotype showed higher body weight and average daily gain than individuals with GHSR-MN genotype.     

南阳牛DGAT2基因PCR-RFLP多态性及其与生长性状相关性研究

以131头纯种南阳牛为研究材料, 利用PCR－RFLPs对二酰甘油酰基转移酶2(DGAT2)基因的第6内含子和第7内含子的多态性及其与生长发育的相关性进行了分析。结果表明: 南阳牛在该位点分别检测到两种等位基因A/B和N/M, 频率分别为0.875/0.125和0.971/0.029。A和N等位基因是群体中的优势等位基因。该基因内含子6对南阳牛6月龄的体高、2岁体重、6月龄到两岁的胸围和体斜长都有显著的影响, 内含子6的AA基因型的6月龄的体高比杂合型高3.8 %, 两岁体重高3.9%, 6月龄到两岁的胸围分别高3.8%、3.4%、3.7%、4.3%; 6月龄到两岁的体斜长分别高3.8%、3.6%、3.8%、3.1%。内含子7对18月龄和两岁的坐骨端宽有极显著的影响(P<0.01); 对两岁的胸围有显著的影响(P<0.05)。     

Association between polymorphisms in the SLC27A1 gene and milk production traits in Chinese Holstein cattle

We assessed SLC27A1, a candidate gene for milk production traits in Chinese Holstein cattle. DNA was extracted from the blood of 48 top Chinese Holstein Cattle selected according to phenotypic character and mixed into DNA pool for SNP detection. We tested blood samples of these cattle for SNPs in exon 3 and the 3'-flanking region of the SLC27A1 gene by using polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) and DNA sequencing. We found 2 polymorphic sites: 112T>C, a synonymous mutation, in exon 3 (SNP(1)), and 64G>A in the 3'-UTR (SNP(2)). We also determined the genotypes of 330 Chinese Holstein cattle by using PCR-restriction fragment length polymorphism (RFLP). We found 3 genotypes each at SNP(1) (TT, TC, and CC) and SNP(2) (GG, GA, and AA). The association among the different genotypes at these 2 sites and milk production traits was analyzed using a least-squares procedure. The results showed that cows with genotype CC had higher milk yields than those with genotype TC (0.01 < p < 0.05). No significant difference was detected among the 3 SNP(2) genotypes in terms of milk production traits. Our results provide evidence that the C allele have potential effects on milk yield trait.     

Biotransformation of p-, m-, and o-hydroxybenzoic acids by Panax ginseng hairy root cultures

The regioselective glycosylation of three isomers of hydroxybenzoic acids was observed in Panax ginseng hairy root cultures. p-Hydroxybenzoic acid (1) and m-hydroxybenzoic acid (2) were converted into their corresponding glycosides (1a and 2a) and glycosyl esters (1b and 2b) while no metabolite of o-hydroxybenzoic acid (3) was detected. A new compound, m-hydroxybenzoic acid β-d-xylopyranosyl (1 → 6)-β-d-glycopyranosyl ester (2c) was identified as a biotransformation product of 2. Further time-course studies of the biotransformation reactions showed that the glycosides were major products in the latter stage. The addition of carbohydrates or antioxidants increased glycosyl esters formation.     

牛POMC基因多态性及其与南阳牛生长性状的相关分析

为研究阿片黑皮质素前体(POMC)在动物采食和能量平衡调控中发挥重要作用, 文章采用PCR-SSCP结合DNA测序方法, 对秦川牛、南阳牛、郏县红牛、晋南牛、鲁西牛、安格斯牛和荷斯坦奶牛共计480头个体POMC基因的多态性进行研究, 并分析了多态位点与南阳牛生长性状的相关性。结果表明, 牛POMC基因3个位点中, 在3′侧翼区P3位点新发现3个连锁存在的SNP(811845 C>T、811821 T>C和811797 A>G, 与NW_928357对照)。POMC基因3′侧翼区多态位点与南阳牛6月龄体重和0~6月龄平均日增重显著相关, BB型个体显著大于AA型(P<0.05)。     

Association of CAST gene polymorphisms with carcass and meat quality traits in Yanbian cattle of China

Bovine calpastatin (CAST) gene polymorphisms have been associated with meat tenderness traits; however, little is known about how the CAST gene affects beef quality traits. In this study, 25 single nucleotide polymorphisms were detected in the CAST gene using polymerase chain reaction with single-strand conformation polymorphism and gene sequencing. Different preponderant genotypes were found at the corresponding gene locus. The E1-1, E1-2, and C3-1 loci were correlated with meat tenderness height and highly correlated with the fatty acid content and the amino acid content. The E4-2 locus was not correlated with meat tenderness, but it was correlated with cooking loss, brightness, and yellowness, among others. The CAST gene is a potential marker for these meat quality traits, but further research is required.     

Genetic polymorphisms of lipoprotein lipase gene and their associations with growth traits in Xiangxi cattle

Lipoprotein lipase (LPL), involved in the metabolism and transport of lipids, regulate energy balance, fat deposition and growth traits. The objective of this study was to investigate the single nucleotide polymorphisms (SNPs) of LPL gene and to determine their associations between these polymorphisms and growth traits in Xiangxi cattle breed. In this study, six novel SNPs (C355157T, T355169C, T355186G, A355210G, T355348A and T355420C) and one reported SNP (A355427T, has been recorded in dbSNP, ID rs110590698) were detected using polymerase chain reaction and DNA sequencing method. Genotyping and genetic diversity analysis were performed in 240 Xiangxi cattle on the basis of sequence alignment, which indicated that five SNPs (C355157T, 355186G, T355348A, T355420C, A355427T) were in abundant genetic diversity, and the other two SNPs (T355169C and TA355210G) were in low genetic diversity. Linkage disequilibrium analysis showed that 18 different haplotypes were identified in these animals. Moreover, the results of the association between LPL gene polymorphisms and growth traits indicated that the individuals with H1H1 haplotype combination had higher BW and HG than those with other haplotype combinations (P?<?0.05). The animals with CC genotype maintain higher mean values for BW than those with the CT and TT genotypes (P?<?0.05) at T355420C locus. The animals with the AA genotype have lower mean values for WH, BL, HG and BW than those with the AT and TT genotypes at A355427T locus (P?<?0.05). The results suggested that the SNPs of the LPL gene might be useful genetic markers for growth traits in the bovine reproduction and breeding.     

Novel SNPs in the bovine Transmembrane protein 18 gene, their linkage and their associations with growth traits in Nanyang cattle

Transmembrane protein 18 (TMEM18) gene is expressed in the central nervous system that has recently been linked to human obesity and body mass index (BMI) in genome wide association studies (GWAS). In this study, two novel single nucleotide polymorphisms (SNPs), g.3835 G > A (aa. Gly > Ser) and g.3865 A > G were detected in cattle TMEM18 gene by DNA sequencing. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and forced PCR-RFLP methods were used to genotype the two SNPs in 1218 Chinese native cattle individuals. The association between novel SNPs and growth traits (especially on body weight and body height) in Nanyang cattle showed that individuals with GG genotype was higher than those with AA genotype at g.3835G>A locus (P < 0.05) in Nanyang cattle. Significant association also revealed that individuals of AA genotype at g. 3865 A>G locus were higher in terms of body weight, average daily gain, chest circunmference, body length (P < 0.05), body height and hucklebone width (P < 0.01) than GG genotypes in Nanyang cattle. Moreover, the effect of XspI-MluI combinations with growth traits in Nanyang cattle revealed that AAGG type had higher body weight, body length, chest circumference and average daily gain (P < 0.05) than GGAG in Nanyang cattle aged at 6 months.     

Oxidation of both termini of p- and m-xylene by Escherichia coli transformed with xylene monooxygenase gene

Xylene monooxygenase (XMO) from Pseudomonas putida mt-2 catalyzes oxidation of methyl group of toluene and xylenes. While it has been postulated that this enzyme oxidizes one methyl group of xylene, we observed that both methyl groups in p- and m-xylene were oxidized to alcohol and aldehyde when the relevant genes (xylM and xylA) were co-expressed in Escherichia coli C600 and MC4100. When p-xylene was used as a substrate, p-hydroxymethylbenzaldehyde and p-xylyleneglycol were identified, in addition to p-methylbenzylalcohol and p-tolualdehyde. When m-xylene was used as a substrate, m-hydroxymethylbenzaldehyde and m-xylyleneglycol were identified, in addition to m-methylbenzylalcohol and m-tolualdehyde. Ratio of the products varied significantly according to the reaction condition and host strain, presumably reflecting the relative activity of XMO and host-derived dehydrogenase(s). Using various oxidized compounds as substrates, it was indicated that dialcohol (p- or m-xylyleneglycol) was formed via p- or m-hydroxymethylbenzaldehyde, respectively, rather than directly from corresponding monoalcohol (p- or m-methybenzylalcohol).     

Association between molecular markers for beef tenderness and growth traits in Argentinian angus cattle

Molecular markers for beef tenderness are classic examples of the contribution of genome technology to animal breeding through marker-assisted selection (MAS). Markers on the μ-calpain (CAPN1) and calpastatin (CAST) genes have been extensively evaluated for their association with tenderness. However, little is known about their potential effect on other economically important traits. In this work, the association of molecular markers for beef tenderness with growth traits was evaluated in Angus cattle of Argentina. Expected progeny differences were extracted from the 2008 Angus Sire Summary of Argentina. Information corresponding to 268 influential bulls that had been genotyped for two markers in CAPN1 and two markers in CAST was provided by the Argentine Angus Association. Genotype probabilities were assigned, by segregation analysis, to those bulls in the Sire Summary that had no marker information. Expected progeny differences of 1365 sires were regressed on the number of alleles favouring tenderness at each locus. There was a significant effect of markers on expected progeny differences of birth weight, weaning weight (direct), weight at 18 months and rib eye area. In general, there was a negative effect of alleles favouring tenderness on growth traits. These correlated responses should be taken into account when molecular markers are used in selection schemes that aim to improve beef tenderness.     

Association analysis of adiponectin and somatostatin polymorphisms on BTA1 with growth and carcass traits in Angus cattle

This study tested positional candidate genes adiponectin (ADIPOQ) and somatostatin (SST) for effects on carcass traits in a commercially relevant cattle population. Both genes are located within a region of BTA1 previously reported to harbour quantitative trait loci (QTL) that affect marbling, quality grade, yield grade, ribeye area and weaning weight in Bos taurus x Bos indicus crosses. Except for the first intron of ADIPOQ, both genes, including over 2 kb upstream of the promoters, were sequenced in five registered Angus sires to identify polymorphisms. A variable copy duplication and three single nucleotide polymorphisms (SNPs) in ADIPOQ and one SNP in SST were genotyped and tested for association with 19 traits in a 14-generation pedigree of 1697 registered Angus artificial insemination sires representing all the major USA lineages of the breed. Linear models that parameterized predicted genetic merits in terms of allele substitution effects were fit by weighted least squares, and goodness-of-fit tests were employed to differentiate causal mutations or polymorphisms in strong linkage disequilibrium (LD) with causal mutations from markers in weak LD with QTL. We confirmed the presence of QTL affecting marbling, ribeye muscle area and fat thickness in the vicinity of SST and ADIPOQ on BTA1 in Angus; excluded SST as underlying the ribeye muscle area QTL; and excluded ADIPOQ as underlying the marbling score QTL. However, association analysis provides very limited information about QTL location and has little intrinsic value when performed in the absence of linkage or LD analysis using flanking marker data to localize the QTL effect relative to positional candidate genes.     

Association between polymorphisms of Myf5 and POU1F1 genes with growth and carcass traits in Hanwoo (Korean cattle)

Myogenic factor 5 (Myf5) and POU class 1 homeobox 1 (POU1F1) genes play important roles in growth and development of mammals. Bovine Myf5 and POU1F1 were characterized to detect genetic variation at these loci and to replace them to economic traits in 367 cattle representing Hanwoo (325) and Angus (37). Two single nucleotide polymorphisms (SNPs) were identified in intron 2 (A1948G SNP) of Myf5 and exon 6 (A15635G SNP) of POU1F1 by sequence analyses of genomic DNA. Statistical analysis indicated that the Myf5 polymorphisms significantly (0.05) associated backfat thickness and live weight at 6-months-of-age and that POU1F1 polymorphisms significantly influenced carcass weight and live weight at 24-month of age, and backfat thickness. The interaction between Myf5 and POU1F1 was significant on carcass weight, M. longissimus dorsi area, backfat thickness and marbling score. The results implicate Myf5 and POU1F1 as candidate genes of growth and carcass traits, and suggest that the interaction between Myf5 and POU1F1 strongly affect growth and carcass traits in cattle.