猪CAST基因多态性研究

采用3种限制性内切核酸酶对153头杜洛克猪、内江猪和荣昌猪的钙蛋白酶抑制蛋白(CAST)基因进行PCR-RFLP分析。结果表明:1)HinfⅠ、MspⅠ和RsaⅠ均检测到多态性,同时还发现1个杜洛克个体的HinfⅠ-RFLP出现120bp突变片段。2)X2检验表明,HinfⅠ、MspⅠ和RsaⅠ酶切所产生的基因及基因类型处于Hardy-Wenberg平衡状态(P<0.05);杜洛克、内江猪和荣昌3个品种猪的优势基因型分别为ABCCEE、AACCEE、AACCFF,在99%程度上分别与相应的品种有关。     

皖南三黄鸡IGF-Ⅰ基因多态性与体型指标关联研究

采用PCR-RFLP技术,对105只皖南三黄鸡胰岛素样生长因子-Ⅰ(IGF-Ⅰ)基因的3个SNPs座位进行了检测,并分析了它们对皖南三黄鸡体型性状的遗传效应。结果表明:HinfⅠ、PstⅠ和TaqⅠ识别座位分别发生A→C、C→T和T→C突变,每个SNPs座位各出现了3种基因型,其中PstⅠ酶切位点处于Hardy-Weinberg平衡状态(P0.05),其他2个酶切位点则处于Hardy-Weinberg非平衡状态(P0.05)。分析PstⅠ酶切位点出现的基因型与300日龄体型指标时,发现基因型对胸深有显著影响(P0.05),EF基因型显著高于EE基因型(P0.05),极显著高于FF基因型(P0.01)。     

H-FABP基因型对中畜黑猪I系生长性能的影响

利用PCR RFLP技术(限制性内切酶采用HinfⅠ和HaeⅢ)检测了培育品种77头中畜黑猪I系的心肌脂肪酸结合蛋白(H FABP)基因座位的遗传变异,同时对H FABP的不同PCR RFLP基因型对生产性能的影响作了初步统计分析,旨在探讨利用H FABP进行肉质性状辅助选择,是否对生产性能产生不利影响。结果表明,在H FABP基因5′上游和内含子2 区段,均发现HinfⅠRFLP 和HaeⅢRFLP、HinfⅠ* RFLP;结果显示,在HinfⅠRFLP位点上,HH和hh 2种基因型间个体170日龄体重差异显著(P<0.05),除此之外,未发现其它酶切位点的不同基因型个体生长性能之间的显著差异。研究结果为今后开展猪肉质性状和生产性能的分子辅助选育奠定应用基础。     

垂体特异性转录因子1基因遗传多态性与中国西门塔尔牛生长及育肥性状的遗传效应分析

本研究旨在分析垂体特异性转录因子(Pit-1)基因SNPs与中国西门塔尔牛生长和育肥性状的相关性。试验以118头中国西门塔尔牛为材料,利用DNA测序和PCR-RFLP方法检测Pit-1基因Hinf Ⅰ酶切位点多态性,并进行相关分析。结果表明,Hinf Ⅰ酶切位点与料重比和平均日增重性状呈显著相关(P＜0.05),其中BB基因型个体显著优于AA基因型个体,饲料转化率较低,平均日增重较高;在8、15月龄体高性状,12、15月龄体长性状,8、12、15月龄胸围性状和8月龄腹围性状中,Hinf Ⅰ酶切位点多态差异显著,BB基因型个体表型值显著高于AA基因型(P＜0.05);在宰后体尺性状测量性状中,Pit-1基因Hinf Ⅰ多态位点对胴体长、胴体胸深和腰部肉厚性状影响显著,其中BB基因型个体表型值显著大于AA和AB基因型个体(P＜0.05)。初步认为,BB基因型与优良的生长育肥性能显著相关,对B等位基因的选择有利于优良性状的改良。     

三江白猪H-FABP基因多态性和肌内脂肪含量相关性分析

利用PCR-RFLP技术检测了80头三江白猪H-FABP基因的5'-上游区和第2内含子区的遗传变异,并用最小二乘法模型分析了H-FABP基因对猪肌内脂肪含量的遗传效应。结果表明:在H-FABP基因5'-上游区域HinfⅠ-RFLP和第2内含子MspⅠ-RFLP均不存在多态性,基因型为HH和AA。第2内含子HinfⅠ*-RFLP(基因型BB、Bb、bb)和HaeⅢ-RFLP(基因型DD、Dd、dd)均有多态性,肌内脂肪含量bb高于Bb型,但肌内脂肪含量差异不显著(P>0.05);dd基因型肌内脂肪含量显著高于Dd和DD基因型(P<0.05)。通过各种组合基因型发现,AAddbbHH基因型具有最高的IMF含量,因此可通过提高"AAddbbHH"基因型的频率来增加肌内脂肪含量,达到改善猪肉质的目的。     

山羊LIM同源框基因LHX3分子遗传特征研究

利用PCR-RFLP、Forced-PCR-RFLP、DNA测序法研究中国西农萨能奶山羊(Sa)、关中奶山羊(GZ)和内蒙古白绒山羊(IMWC)3个品种LHX3基因的分子遗传特性.结果表明,在第2内含子452 nt处存在T＞C的突变,第6外显子352 nt处存在T＞C的突变.在Hinf Ⅰ位点,GZ、Sa和IMWC的等位基因T/C频率分别为0.492 9/0.507 1,0.376 3/0.623 7,0.698 4/0.301 6;在Msp Ⅰ位点,GZ、Sa和IMWC的等位基因T/C频率分别为0.492 9/0.507 1,0.633 8/0.366 2,0.267 2/0.732 8;以上位点在不同品种中的多态信息含量(PIC)在0.314 9～0.374 9之间.独立X2分析表明,Hinf Ⅰ和Msp Ⅰ位点的基因型频率分布在不同山羊品种间均存在极显著差异,暗示品种因素对这些基因型的分布具有显著影响.     

DIV2系猪H-FABP基因多态性与经济性状相关性分析

以H-FABP基因作为猪主要经济性状的候选基因,采用PCR-RFLP检测H-FABP基因多态性位点在中国瘦肉猪新品系（D IV2）中的分布情况,并分析这些多态性位点与平均背膘厚、瘦肉率、日增重和料重比等经济性状的相关性。结果表明,在H-FABP基因的3个位点中,5’上游区域的Hinf I酶切位点为偏态分布,第二内含子的HaeⅢ和HinfⅠ酶切位点为多态性分布,此外,HaeⅢ酶切位点与瘦肉率存在相关性,DD基因型个体的瘦肉率显著高于dd基因型个体（P〈0.05）。     

4个猪种CAST基因与背膘厚关系的研究

钙蛋白酶抑制蛋白(CAST)与猪肉质性状有关,已经作为猪肉嫩度的候选基因.用PCR-RFLP 技术对CAST基因的丝氨酸(Ser) 突变为精氨酸(Arg)进行研究,并用SAS8.02研究了辽宁黑猪、大约克、长白猪和杜洛克4个品种中该突变与背膘厚的关系.结果表明:在辽宁黑猪和大约克猪中检测到AA、AC和CC 3种基因型,而长白猪和杜洛克猪中未检测到CC基因型;辽宁黑猪A的基因频率显著低于其他3个猪种(P<0.05);3种基因型间的背膘厚相比差异显著(P<0.05).     

藏猪SLA-DRB基因第2外显子PCR-RFLP多态性分析

采用限制性内切酶RsaⅠ对藏猪SLA-DRB基因外显子2进行多态性分析。结果表明：藏猪SLA-DRB基因外显子2在RsaⅠ-RFLP位点上存在7种基因型，以杂合子BC型居多，基因型频率为0.4419，为优势基因型。χ2适合性检验结果表明，藏猪SLA-DRB基因外显子2 的RsaⅠ酶切位点的χ2值为10.14，高于显著水平（P<0.05），说明藏猪SLA-DRB基因在RsaⅠ酶切位点上没有达到Hardy-Weinberg平衡状态。     

13/17罗伯逊易位猪POU1F1基因多态性与经济性状的相关分析

利用外周血淋巴细胞培养制备染色体标本,对13/17罗伯逊易位猪的3种杂交组合的394头后代猪进行分群;应用PCR-RFLP技术在POU1 F1基因的扩增片段(1746 bp)中检测到1个RsaⅠ限制性内切酶的多态酶切位点A(3种基因型);应用PCR-SSCP技术检测1个POU1 F1基因第5内含子上的突变E(2种基因型),同时结合生长和胴体品质测定记录研究基因型对生产性状的遗传效应。结果表明,位点A的基因型对生长有显著影响(P<0.05),位点E基因型对生长和眼肌面积有显著影响(P<0.05)。研究结果初步揭示POU1 F1多态性与生长、眼肌面积等存在相关,推测POU1 F1多态性可作为罗伯逊易位杂合优势遗传机制的一种分子水平上的解释。     

Effects of calpastatin and micro-calpain markers in beef cattle on tenderness traits

The objective of this study was to assess the association of single nucleotide polymorphisms (SNP) developed at the calpastatin (CAST) and mu-calpain (CAPN1) genes with meat tenderness and palatability traits in populations with diverse genetic backgrounds. Three populations were used in the study. One population consisted of Bos taurus that included crossbred animals derived from Hereford, Angus, Red Angus, Limousin, Charolais, Gelbvieh, and Simmental (GPE7; n = 539). Another population consisted of Bos taurus with Bos indicus influence, including crossbred animals from Hereford, Angus, Brangus, Beefmaster, Bonsmara, and Romosinuano (GPE8; n = 580). The third population was Bos indicus and consisted of purebred Brahman (STARS; n = 444). Traits evaluated were meat tenderness measured as Warner-Bratzler shear force (WBSF; kg) at 14 d postmortem, and traits evaluated by trained sensory panels that included tenderness score, juiciness, and flavor intensity. A SNP at the CAST gene had a significant (P < 0.003) effect on WBSF and tenderness score in the GPE7 and GPE8 populations. Animals inheriting the TT genotype at CAST had meat that was more tender than those inheriting the CC genotype. The marker at the CAPN1 gene was significant (P < 0.03) for tenderness score in GPE7 and GPE8. Animals inheriting the CC genotype at CAPN1 had meat that was more tender than those inheriting the TT genotype. Markers at the CAST and CAPN1 genes were associated with flavor intensity in the GPE8 population. Animals inheriting the CC genotype at CAST and the TT genotype at CAPN1 produced steaks with an intense flavor when compared with the other genotypes. An interaction between CAST and CAPN1 was detected (P < 0.05) for WBSF on GPE8. The statistical significance of the interaction is questionable because of the limited number of observations in some cells. Markers developed at the CAST and CAPN1 genes are suitable for use in identifying animals with the genetic potential to produce meat that is more tender.     

草原红牛改良群体H FABP基因SNP及其与肉质性状的相关分析

试验采用PCR-SSCP的方法对含1/2利木赞血缘的改良草原红牛的H-FABP基因5’-调控区进行SNP分析,并分析其多态性与改良草原红牛肉质性状的相关性。结果表明：改良草原红牛H-FABP基因5’-调控区存在多态位点,在136位点发生1个T碱基的插入突变,在142位点,发生了G→A转换。相关分析结果显示剪切力在AA和AB、BB基因型间差异极显著（P<0.01）,AB与BB基因型间差异不显著（P>0.05）,A基因对剪切力有负效应,其余肉质性状在不同基因型间差异均不显著（P>0.05）。表明H FABP基因对改良草原红牛肉质嫩度有显著影响。     

鸡钙蛋白酶抑制蛋白基因多态性及其与肉质性状的相关性

为探讨钙蛋白酶抑制蛋白(Calpastatin,CAST)基因作为影响鸡肉质性状候选基因的可能性,本研究以8个优质鸡新品系为试验材料,采用PCR-SSCP方法对CAST基因的部分编码区进行单核苷酸多态性(SNPs)检测。结果发现了CAST基因1个多态性位点(G→T),使试验鸡群表现出AA、BB和AB这3种基因型。利用SAS(8.01)软件统计分析了3种基因型与优质鸡肉质性状的相关性,结果表明,CAST基因的多态性对鸡肌内脂肪含量、肌纤维密度和直径有显著的影响(P0.05),对其他肉质性状无显著影响(P0.05);推测CAST基因可能对鸡肉质性状具有很大的影响或与控制肉质性状的主基因连锁。     

Association of a single nucleotide polymorphism in the calpastatin gene with carcass and meat quality traits of beef cattle

Calpastatin (CAST) is a naturally occurring protein that inhibits the normal tenderization of meat as it ages postmortem. A SNP was identified in the CAST gene (a G to C substitution) and genotyped on crossbred commercially fed heifers (n = 163), steers (n = 226), and bulls (n = 61) from beef feedlots, and steers (n = 178) from a University of Guelph feeding trial. The association of the CAST SNP with carcass and meat quality traits was studied. Carcass traits included fat, lean, and bone yield; grade fat; LM area; and HCW. Meat quality traits included marbling grade; i.m. fat content of LM; tenderness evaluation of LM (Warner-Bratzler shear force) at 2, 7, 14, and 21 d of postmortem aging; and tenderness evaluation of semitendinosus muscle at 7 d of postmortem aging. The mixed model used in the analyses included fixed effects of CAST genotype, sex, slaughter group, and breed composition (linear covariate); sire was a random effect. For the analysis of shear force, i.m. fat content of LM was also included in the model as a linear covariate. Shear force measures were analyzed within days of postmortem aging and by repeated measures analysis. The CAST SNP allele C was more frequent (63%) in the crossbred population than allele G. The CAST SNP was associated with shear force across days of postmortem aging (P = 0.005); genotype CC yielded beef that was more tender than GG (-0.32 kg +/- 0.13), and CG had intermediate tenderness. The corresponding average allele substitution effect (G to C substitution) was also highly significant (-0.15 +/- 0.05 kg, P = 0.002). A lower percentage of unacceptably tough steaks (shear force > 5.7 kg) at 2 and 7 d postmortem was associated with an increasing number of C alleles (P < or = 0.05). At 7 d postmortem, the percentage of unacceptably tough steaks decreased by 24 and 35%, respectively, for animals carrying 1 and 2 copies of the C allele relative to animals with no C alleles. However, genotype CC had a greater fat yield (+1.44 +/- 0.56%; P = 0.037) than genotype GG, with a corresponding allele substitution effect of 0.67 +/- 0.27% (P = 0.015). Therefore, the CAST SNP allele C was associated with increased LM tenderness across days of postmortem aging and, importantly for the beef industry, had a significant reduction in the percentage of steaks rated unacceptably tough by consumers based on an assumed threshold level.     

湘村黑猪sirt2基因多态性及其与肉质性状的关联分析和组织表达研究

本研究旨在探索沉默信号调节子家族(silent information regulator 1-7,SIRT1-7)sirt2基因在湘村黑猪不同组织间的表达及其多态性与肉质性状间的关联性,以期寻找与湘村黑猪肉质性状相关的分子标记。采用PCR-RFLP方法和基因测序技术对湘村黑猪sirt2基因多态位点进行分析,采用实时荧光定量PCR技术对sirt2基因在湘村黑猪心脏、肝脏、脾脏、肺脏、肾脏、胰腺、后腿肌和背最长肌8个组织中的相对表达量进行分析,利用SAS 9.4软件对sirt2基因突变位点不同基因型与肌肉色值、pH_(45 min)、pH_(24 h)、滴水损失、失水率、肌内脂肪、嫩度和眼肌面积进行关联分析。结果显示,在湘村黑猪sirt2基因第8外显子扩增片段中的240 bp处发现1处C→T碱基突变,编码氨基酸由精氨酸(Arg)变为半胱氨酸(Cys),为错义突变,并形成CC、CT和TT 3种基因型,CC基因型为优势基因型,C为优势等位基因,经χ~2检验表明该突变位点偏离哈代-温伯格平衡;该位点群体纯合度较高,有效等位基因数为1.301,多态信息含量为0.205,为低度多态(PIC<0.25)。基因多态性与肉质性状关联分析结果表明,TT基因型肉色L~*值和滴水损失显著低于CC和CT基因型(P<0.05),CC基因型失水率显著高于CT和TT基因型(P<0.05)。sirt2基因在湘村黑猪8个组织中均有表达,其中在背最长肌中相对表达量最高,与肺脏中表达量差异不显著(P>0.05),但显著高于心脏、肝脏、脾脏、肾脏、胰腺和后腿肌(P<0.05),且心脏、肝脏、脾脏、肾脏和胰腺中相对表达量差异均不显著(P>0.05)。本试验结果表明,sirt2基因对湘村黑猪肉质性状的发育有一定影响,可作为影响湘村黑猪肉质性状的候选基因进行深入研究。     

The Polymorphisms of MSTN Gene and Its Relationship with Meat Quanlity Traits in Gaopo Pig

To explore the influence of Gaopo pig myostatin (MSTN) gene polymorphism on meat quanlity traits (moisture,crude fat,crude protein,crude ash, loin muscle area, marbling score, pH value, color of meat,tenderness,drip loss, water loss rate), MSTN gene was chosen as a candidate gene for research meat quality traits in this study. 50 Gaopo pigs at 10 months old were selected,the single nucleotide polymorphism (SNP) of three exons of MSTN gene in Gaopo pig were detected by direct sequencing of PCR amplification products, and the correlation between MSTN gene SNP and meat quality traits was analyzed using SPSS 20.0 software. The results showed that a C/T mutation had been found at 63 bp of MSTN gene exon 3,the site was silent mutation, and did not caused changes of encoding amino acid. Genotype analysis showed only three samples had mutations in the site, CC genotype was the dominant type and allele C was the dominant gene, but there was no TT homozygous genotype. The test of Hardy-Weinberg equilibrium showed the research group obeyed the genetic equilibrium (P>0.05). Population genetic parameter analysis showed the heterozygosity (He) of C63T was lower, and had a low variation in Gaopo pig population. Polymorphism information content (PIC) analysis showed that it was a low polymorphic loci (PIC<0.25), and the site could provide a little genetic imformation. There was no significant difference between the different genotypes and meat quality traits (P>0.05).Given the above, the polymorphism of MSTNgene exon was found in Gaopo pig, with less variation and relatively conservative.It's needed to expand the number of sample for further explore whether the site could be considered as genetic markers for meat quality traits of Gaopo pig or not.     

高坡猪肌肉生长抑制素基因多态性及其与肉质性状的相关性分析

为了探讨肌肉生长抑制素（myostatin,MSTN）基因的多态性对高坡猪肉质性状（水分、粗脂肪、粗蛋白质、粗灰分、眼肌面积、大理石纹、pH、肉色、嫩度、滴水损失、失水率）的影响,试验以MSTN基因作为肉质性状候选基因,以10月龄的50头高坡猪为研究对象,采用PCR扩增产物直接测序的方法对高坡猪MSTN基因3个外显子的单核苷酸多态性（SNP）进行研究,运用SPSS 20.0软件分析MSTN基因SNP与肉质性状的关联性。结果表明,仅在高坡猪MSTN基因第3外显子63 bp处检测到1个C/T突变位点,该突变为同义突变,未引起编码氨基酸的改变。基因型分析发现,仅有3个个体在该位点发生突变,CC基因型为优势基因型,C为优势等位基因,无TT纯合基因型。经χ²适合性检验分析,该SNP在研究群体中处于Hardy-Weinberg平衡状态（P>0.05）。群体遗传参数分析发现,C63T标记位点的杂合度（He）相对较低,表明其在高坡猪群体中的变异较小;就多态信息含量（PIC）而言,该位点属于低度多态（PIC<0.25）,说明该遗传标记能够提供少量的遗传信息。将该位点的不同基因型与肉质性状指标进行关联分析表明,所有肉质性状指标在不同基因型间差异均不显著（P>0.05）。综上所述,MSTN基因外显子在高坡猪中存在多态性,但变异较少,相对保守,能否作为高坡猪肉质性状的遗传标记有待于扩大样本数量进一步研究。     

谷胱甘肽对肉羊生长性能、屠宰性能及肉品质的影响

选择东北细毛羊×德国肉用美利奴的杂交一代肉羊12只,分成对照组、试验Ⅰ组和Ⅱ组,每组4只,研究谷胱甘肽对肉羊生长性能、屠宰性能及肉品质的影响。试验期60 d。结果表明:与对照组相比,谷胱甘肽显著提高了肉羊的日增重(P<0.05),试验Ⅰ组、Ⅱ组分别提高了14.6%和11.4%;降低了肉羊的料重比(P<0.05),试验Ⅰ组、Ⅱ组分别降低了11.0%和8.1%。试验Ⅰ组的净肉率和GR值显著高于对照组(P<0.05),Ⅱ组的宰前活重显著高于对照组(P<0.05);试验Ⅰ组肉的剪切力显著低于对照组(P<0.05);试验Ⅰ组、Ⅱ组的滴水损失显著低于对照组(P<0.05),而熟肉率显著高于对照组(P<0.05),且两试验组间差异不显著(P>0.05);各试验组宰后45 min内肉的pH没有显著差异(P>0.05),但试验Ⅰ组24 h的pH极显著地高于其他2组(P<0.01)。     

猪肉质性状功能基因在野猪群体内的变异研究

本试验旨在研究猪肉质性状功能基因突变位点在野猪群体里面的遗传变异规律。以MC4R基因(D298N G>A)、RYR1基因(c.1843 C>T)、PRKAG3基因(1849 G>A)和IGF2基因(3072 G>A)突变位点为基础,通过PCR-RFLP、PCR-SSCP技术,对72头圈养野猪群体进行突变位点的多态性检测和群体遗传变异分析。结果表明,RYR1基因在c.1843 C>T突变位点的CC基因型为野猪群体内的优势基因型,等位基因C是野猪群体内的优势基因,没有TT基因型,该突变位点处于不平衡状态(P<0.01和P<0.05)。在MC4R基因D298N G>A突变位点上,GG基因型为野猪群体内的优势基因型,等位基因G是野猪群体内的优势基因。而PRKAG3基因(1849 G>A)的突变位点检测结果是GG基因型为野猪群体内的优势基因型,等位基因G是野猪群体内的优势基因,没有发现AA基因型。IGF2基因3072 G>A在野猪群体内没有发现多态性,经测序验证全部为GG基因型。这3个基因突变都处于Hardy-Weinberg平衡状态(P>0.05)。本研究得出该野猪种群体遗传多样性和变异较小,符合其品种特性。     

新疆阿勒泰羊钙蛋白酶抑制蛋白基因多态性与嫩度的关联性分析

为研究钙蛋白酶抑制蛋白（calpastatin,CAST）基因多态性与新疆阿勒泰羊肉嫩度的关系,本试验以89只新疆阿勒泰羊为研究对象,运用PCR-SSCP方法对新疆阿勒泰羊CAST基因第1、2、21外显子进行多态性检测,采用DNA测序技术对结果进行测序,并与新疆阿勒泰羊肉嫩度进行关联性分析。结果显示,在第1和2外显子均未发现多态性,在第21外显子检测出AA、AB、BB 3种基因型,测序结果显示该处发生了A→G的突变。关联分析结果表明,该突变对阿勒泰羊肉嫩度有显著影响（P＜0.05）,初步推断AA基因型可能对阿勒泰羊肉嫩度有一定的改善作用。