中外六个猪种FUT1基因多态性研究

目的对6个中外猪种共245头猪的FUT1基因进行了研究。方法采用PCR-RFLP技术。结果与结论Hin6I位点上,大白猪、长白猪、杜洛克猪3个外来猪种均存在多态,且以敏感型（GG型和AG型）居多;山西黑猪、太原花猪、马身猪3个本地猪种的所有检测样品都表现为GG型。     

3个群体猪FUT1基因M229与M307位点遗传多样性研究

为了探究3种显著差异类型猪FUT1基因M229与M307位点多态分布规律。本实验采用PCR-SSCP、PCR-RFLP结合直接测序技术分别对从江香猪、巴克夏×黔北黑猪F_1代杂交猪和杜×长×大外三元猪群体M229和M307位点多态性进行分析。结果表明,从江香猪M229位点中有效等位基因为1.913 8,多态信息含量为0.363 5,属于中度多态,而在巴克夏×黔北黑猪F_1代杂交猪和杜×长×大外三元猪群体中多态信息含量均低于0.25,为低度多态;与M229位点群体遗传参数结果相反,从江香猪M307位点多态信息含量最低,呈现出偏态分布,而在杜×长×大外三元猪群体中M307位点多态信息含量为0.260 2,可提供较多的遗传信息。因此,今后在从江香猪群体中应以M229位点选育为主,而国外品种应以M307位点选育为主。     

猪FUT1基因对肉质和胴体性状的影响

测定139头杂交猪(大白猪和梅山猪)的14个肉质性状和8个胴体性状,用PCR-RFLP方法检测FUT1基因型。分析猪FUT1基因型间肉质和胴体性状差异,发现AA基因型猪3个部位肌肉pH值均比AG基因型的高,其中pH(LD)达到显著水平(P<0.05)。AA基因型猪肌肉系水力显著高于AG猪的系水力(91.02% VS 86.70%,P<0.05)。AA基因型猪的肉色值显著高于AG猪的(P<0.05)。AA基因型猪三个部位肌肉膘厚值均较低,其中最后肋骨膘厚和倒数三四肋骨膘厚分别比AG基因型猪的低4.26 mm和3.96 mm(P<0.05)。AA基因型猪瘦肉率比AG基因型猪的高3.31% (53.46% VS 50.15%,P<0.05)。以上结果表明FUT1基因的AA基因型对肉质和和胴体性状具有显著的正遗传效应,这对于在抗病育种中应用该基因十分有利。     

贵州白山羊GFI1B基因多态性与生长性状的相关性

本试验旨在研究贵州白山羊GFI1B基因第八外显子的多态性,及其与生长性状的相关性.通过PCR-RFLP技术对贵州白山羊外显子SNPs位点进行检测,利用一般线形模型分析其与生长性状的关联性.结果显示,供试群体中在外显子上检测到2个SNPs位点,即第八外显子263(G/T)和340(G/A).最小二乘法分析表明,G340A位点,CC型和DD型的体重、体长、胸深和胸宽对CD型达到差异及显著水平(p约0.01).本研究检测到的GFI1B基因第八外显子340(G/A)多态性位点可作为贵州白山羊生长性状的候选分子标记.     

猪a1-岩藻糖转移酶基因(FUT1)在26个中外猪种中的遗传变异研究

肠毒素大肠杆菌F18(ECF18)是引起仔猪断奶后水肿和腹泻病的主要病原菌,a1—岩藻糖转移酶基因(FUT1)是ECF18侵染猪小肠的受体蛋白候选基因。通过采用PCR—RFLP方法检测了5个西方商业猪种以及21个中国地方猪种(群)1458个个体在FUT1基因开放阅读框架的307核苷酸位点的G-A点突变(M307^G-A)遗传变异。结果表明：5个外来猪种以及中国地方猪种中的临高猪在该FUT1基因位点存在多态性,其他中国地方猪种均表现为极端的单态分布,只有易感的GG基因型,没有多态性。由此提示：1)如果猪FUT1 M307^G-A点突变是决定猪小肠上ECF18受体表达与否的关键因素,则绝大部分中国地方猪种均不具备抵抗ECF18的遗传基础,这除了表明ECF18抗性基因有可能起源于西方猪种外,同时也表明对中国地方猪种中在这个位点惟一存在多态性的海南临高猪的品种资源保存具有非常重要的意义。2)一般而言,在中国的养猪生产实践中,中国地方猪种的仔猪抗水肿与腹泻病能力普遍强于外来猪种,研究的结果提示有必要对中国地方猪种所具备的上述遗传抗性做更深入的研究,寻找、定位其相应的QTL或／和抗性基因。     

苏姜猪OLR1基因多态性及其与肉质性状的关联分析

探讨OLR1基因在苏姜猪群内的遗传多态性,以及该基因多态对苏姜猪猪肉质性状的影响。采用PCR-RFLP技术检测OLR1基因在苏姜猪试验群体中的PstⅠ酶切遗传多态性,运用单因素方差分析方法分析了该多态位点对苏姜猪肉质性状的影响。结果发现,苏姜猪试验群体OLR1基因内含子5区域内发现一个PstⅠ酶切多态性,检测到CC、CD和DD三种基因型,多态信息含量呈现中度多态性。CC型与DD型个体的肌肉失水率、大理石纹间的差异达到显著水平(P<0.05),CD型个体用色差仪测得的b值显著高于DD型(P<0.05)。因此,检测到的OLR1基因PCR-RFLP-PstⅠ多态性与大理石纹等肉质性状存在着显著的相关关系,可以作为肉质性状候选基因在苏姜猪的持续选育中加以应用。     

天祝白牦牛OXGR1基因多态性与体尺性状的关联性分析

为了研究牦牛α-酮戊二酸（盐）受体1（Oxoglutarate receptor1, OXGR1）基因多态性与其体尺性状的相关性,本文以4-8岁天祝雄性（阉）白牦牛的血液DNA（n=192）为实验材料并构建DNA混合池。通过DNA直接测序法检测OXGR1的核苷酸序列潜在的多态位点;利用高分辨率熔解曲线分析技术 (High Resolution Melting,HRM ) 进行分型。采用SHESIS软件对OXGR1基因多态位点进行连锁不平衡分析;运用 PIC-Calc 0.6软件分析多态信息含量;采用卡方检验检测 Hardy- Weinberg平衡;运用SPSS20.0软件对多态位点与体尺性状进行关联分析;运用RNAFOLD、ExPASy和Swiss-model软件对OXGR1基因突变前后的蛋白结构进行预测分析。结果表明：天祝白牦牛OXGR1基因发现有两个多态位点,分别为347(A/G)和678(G/A),每个位点均有3种基因型（AA、AG、和GG）,其优势基因型分别为GG和AA。两个SNPs均达到Hardy-Weinberg 平衡（P＞0.05）,存在强连锁不平衡（D’＞0.75, R²＞0.33）,且均表现为中度多态（0.25< PIC< 0.5）。上述位点不同基因型在体斜长、体高、胸围和管围存在显著差异（P＜0.05）。分子结构预测显示：347 位点处突变为错义突变,其编码的氨基酸由天冬酰胺变为丝氨酸。突变后OXGR1 mRNA二级结构、蛋白质二级结构及三级结构均发生改变。上述结果表明: OXGR1基因可作为牦牛分子育种的候选分子标记,为今后牦牛遗传资源的保护、开发以及新品种的选育提供依据。     

IGF2基因PCR-RFLP多态性与脂肪沉积相关性状的关联分析

胰岛素样生长因子 2在胎儿生长发育、肿瘤细胞增殖、肌肉生长等方面具有重要的调控作用 ,是影响猪瘦肉量的主要候选基因。采用PCR RFLP技术 ,分析了IGF2基因第 8内含子部分片段在猪资源家系群体中的NciⅠ酶切片段多态性分布。IGF2基因该片段具有两个NciⅠ酶切位点 (切点位于第 8内含子 ,分别记录为位点A和位点B) ,两位点在资源家系中均具有多态性。IGF2基因B位点酶切未突变个体均比酶切突变的个体背膘薄 18 2 8% (P<0 0 1) ,肥肉率低 2 2 4 3% (P <0 0 1) ,瘦肉率高 8 71% (P <0 0 1) ,位点A具有相同的影响趋势。在该研究群体中 ,IGF2基因发挥作用的方式主要为加性效应 ,可作为猪提高瘦肉率的候选基因     

猪a1-岩藻糖转移酶基因(FUT1)M857位点遗传变异分析

肠毒素大肠杆菌 (ETEC) F18是引起仔猪断奶后水肿和腹泻病的主要病原菌, a-1岩藻糖转移酶(FUT1)基因是ECEC F18侵染猪小肠的受体蛋白基因。利用PCR-RFLP方法检测了1个野猪以及20个中外家猪猪种(群)共696个个体在FUT1基因开放阅读框架的857核苷酸位点的遗传变异, 结果表明: 在所有猪种中, 均未检测到抗性的AA型纯合子, 在外来猪种杜洛克和约克夏、国内猪种临高猪和杂交猪种中检测到AG型杂合子, 外来猪种中的皮特兰、长白猪以及除临高猪外的所有国内猪种和野猪均表现为极端的单态分布, 只有易感的GG基因型。研究结果提示, 中国地方猪种不具备抵抗ETEC F18大肠杆菌的遗传基础, 与外来猪种确实存在差异, 这种差异可能与各自不同的起源有关, ETEC F18抗性基因可能起源于欧洲野猪; 并推测猪种的生长速度与ETEC F18大肠杆菌病的发生具有密切的关系。     

山羊GOLA-DQB1基因外显子2多态性与免疫性状的相关分析

利用PCR-RFLP技术, 对莱芜黑山羊、鲁波山羊和波尔山羊3个山羊种群共 175 只个体的GOLA-DQB1基因外显子2进行遗传多态性研究, 并对山羊种群的血液免疫指标的效应进行了分析。结果表明: 3个山羊种群共检测到(AA、BB、CC、AB、AC、BC、DD)7种基因型, GOLA-DQB1基因外显子2的第24、151位的碱基表现出多态性。多数指标品种效应是主要效应。莱芜黑山羊中, BC基因型的淋巴细胞百分比(W-SCR)显著高于AC 、CC基因型(P<0.05), 中性球比例(W-LCR)显著低于CC基因型(P<0.05), 大型白细胞数(W-LCC)低于AC、CC基因型, 但差异不显著(P>0.05)。波尔山羊中, BC基因型的W-LCC低于AA 、AB 、BB基因型, 但差异不显著(P>0.05)。鲁波山羊中, BC 、AC基因型的W-LCC显著低于AA基因型(P<0.05)。揭示GOLA-DQB1基因与血液免疫性状有一定的相关性。     

Effect of VNTR polymorphism of the Muc1 gene on litter size of pigs

An investigation was undertaken to study the association between the variable number of tandem repeats polymorphism of the Muc1 gene and the litter size in pigs. Four different alleles were found in three breeds. The sequence analysis shows that the repetitive region of pig Muc1 gene is an array of 108-bp repeats. A total of 2,430 litter records from 897 sows genotyped at Muc1 gene were used to analyze the total number born (TNB) and number born alive (NBA). The study of the effects on litter size suggests that TNB and NBA of genotype AA are the highest in Large White, and the TNB and NBA of the third to ninth parities are 1.61 and 2.29 piglets per litter higher (P < 0.05) than those of the genotype DD, respectively. In Landrace, TNB and NBA of the genotype AA are 1.68 (P < 0.01) and 1.58 (P < 0.05) piglets per litter higher than those of the BB genotype in the third to ninth parities, but for all parities the TNB of genotype AA were 0.76 piglets per litter (P < 0.05) higher than BB. In Duroc, the TNB and NBA of genotype AA are about 1.5 piglets per litter more than those of DD in the third to ninth parities, though not significantly. The research suggests that the smaller allele tends to have higher litter size. The results indicate that Muc1 gene is significantly associated with litter size in pigs.     

Analysis on DNA sequence of KiSS-1 gene and its association with litter size in goats

Three pairs of primers were designed to clone the goat KiSS-1 and scan polymorphisms and four pairs to detect polymorphisms in sexual precocious and sexual late-maturing goat breeds. A 4118 bp DNA fragment was obtained, which contains an ORF of 408 bp and encodes 135 amino acids, having a high homology with other mammals. The protein was predicted containing a signal peptide of 17 amino acids. There are two mutations (G3433A [A86T] and C3688A) in exon 3, three mutations (G296C, G454T and T505A) in intron 1 and a 18 bp deletion (?)/insertion (+) (1960–1977) in intron 2 and no mutations in exon 2. The genotype distribution didn’t show obvious difference between sexual precocious and sexual late-maturing goat breeds and no consistency within the sexual late-maturing breeds. For the 296 locus, the Jining Grey goats with genotype CC had 0.80 (P < 0.01) or 0.77 (P < 0.01) kids more than those with genotype GG or GC, respectively. No significant difference (P > 0.05) was found in litter size between GG and GC. For the 1960–1977 locus, the Jining Grey goat does with genotype ?/? had 0.77 (P < 0.01) or 0.73 (P < 0.01) kids more than those with +/+ or +/?, respectively. No significant difference (P > 0.05) was found in litter size between +/+ and +/? genotypes. For the other four loci, no significant difference (P > 0.05) was found in litter size between different genotypes in Jining Grey goats. The present study preliminarily indicated an association between allele C of the 296 locus and allele (?) of the 1960–1977 locus in KiSS-1 and high litter size in Jining Grey goats.     

Mapping of the porcine oestrogen receptor 2 gene and association study with litter size in Iberian pigs

Genes encoding the oestrogen receptors (ESR) are considered candidate genes for prolificacy traits due to the key role these molecules play in the regulation of reproductive physiology. In this paper, we report the assignment of the pig ESR2 gene to porcine chromosome 1 by radiation hybrid mapping. Most of the ESR2 cDNA was sequenced from Iberian pig ovarian RNA samples and one A/G single nucleotide polymorphism (SNP) was found at exon 5, being associated with a Met/Val substitution at position 949. This SNP was genotyped using a PCR-RFLP (Hsp92II) protocol and its potential effect on litter size was evaluated in two Iberian pig populations. However, no statistically significant association between the ESR2 polymorphism and litter size was found.     

Polymorphism of insulin-like growth factor 1 gene and its association with litter size in Small Tail Han sheep

The insulin-like growth factor 1 (IGF1) gene was studied as a candidate gene for high prolificacy in sheep. Polymorphisms of 5' regulatory region and all four exons of IGF1 gene were detected in Small Tail Han (n?=?277), Hu (n?=?58), Texel (n?=?48) and Dorset (n?=?46) sheep by PCR-RFLP and PCR-SSCP analysis. A microsatellite polymorphic site and a restriction fragment length polymorphism were shown in the 5' regulatory region of IGF1 gene. The ewes with genotype 123/123?bp had 0.81 (P??0.05) in Small Tail Han sheep. These results preliminarily indicated that these polymorphisms of IGF1 gene could be used in molecular marker-assisted selection for sheep breeding programs.     

Effect of polymorphism in the peroxisome proliferator-activated receptor gamma gene on litter size of pigs

The association of polymorphisms in peroxisome proliferator-activated receptor γ (PPARγ) gene with litter size was studied in Large White and Landrace pig. Three SNP loci (P1, P2 and P7) on PPARγ₂ gene were determined by PCR–SSCP and the results showed that there were A → G mutations at 220 and 324 bp in 5′-regulator region and at 147 bp in exon 6, respectively. Allele frequencies were analysed in two breeds. Information on 2341 litter records from 564 sows was used to analyse the trait total number born (TNB) and number born alive (NBA). In Large White, TNB and NBA of genotype BB for P2 locus were the lowest, and the TNB and NBA of third and following parities and all parities were 0.74 and 0.51 piglets per litter less (P < 0.001) than those of the highest genotype AB, respectively, but for P1 and P7 locus the beneficial genotype AA were more 0.4–0.8 piglets per litter (P < 0.05) than the inferior genotype AB. In landrace, TNB and NBA of the first parity of genotype BB for P1 locus were 2.0 piglets per litter higher than AA (P < 0.05), but for all parities the TNB and NBA of genotype BB were 0.66 and 0.97 piglets per litter (P < 0.05) higher than AA, respectively. At P2 locus, the TNB and NBA of the second parity of genotype AA were obviously higher than those of AB (P < 0.05). And at P7 locus, the TNB and NBA of each parity of genotype AA were both about 2 piglets per litter more than those of BB (P < 0.05). The results indicated that PPARγ gene was significantly associated with litter size in pigs.     

Effect of polymorphism in the leukemia inhibitory factor gene on litter size in Large White pigs

DNA polymorphism of the porcine leukemia inhibitory factory (LIF) was investigated and used to study the effects on litter size in Large White pigs. A total of 2,167 litter records from 420 sows genotyped at two SNP loci (LIF1 and LIF2) within LIF gene were analyzed to determine whether LIF influenced total number born (TNB) and number born alive (NBA). The results indicated that B allele at LIF1 locus and A allele at LIF2 locus seem to have advantageous effects on litter size. However, the combined analyzed results demonstrated that genotype AAAA, ABBB, and BBBB are better than genotype AAAB, AABB, and ABAB for TNB and NBA in either third to eighth parity or all parities. In all parities, the sows with AAAA genotype had an advantage of 1.76 piglets (P < 0.001) for TNB and 1.44 piglets (P < 0.01) for NBA per litter over the AAAB sows, respectively. The results in this study demonstrated that LIF gene was significantly associated with litter size in pigs. H. C. Lin and G. F. Liu contributed equally to this work.     

猪ACTA2基因的克隆、表达分析及其与生产性状的关联

为鉴定对猪生产性状有重要影响的新分子标记,文章采用电子克隆结合PCR方法获得了猪肌动蛋白α2(Actin alpha 2, ACTA2)基因编码区序列和部分基因组序列,建立了第2内含子C1554T替换的PCR-HinfⅠ- RFLP基因分型方法,在所检测的7个不同猪群中除大白和梅大群体外,其他群体中均是C等位基因频率高于T等位基因的频率。标记与性状关联分析发现ACTA2基因型与肩部背膘厚、臀部背膘厚、肥肉率、瘦肉率、股二头肌pH和肌内脂肪显著或极显著相关,TT基因型与CC基因型相比具有更高的瘦肉率以及更低的肥肉率和背膘厚。通过Real-time RT-PCR分析发现ACTA2在大白和梅山两个品种猪骨骼肌中的表达量都随着日龄的增加而降低,在各个阶段,梅山猪中的表达量都比大白猪中的表达量高。     

Polymorphism identification in the goat KITLG gene and association analysis with litter size

This study reported the analysis of KIT ligand (KITLG) gene polymorphisms in 681 goats of three breeds: Xinong Saanen (SN), Guanzhong (GZ), and Boer (BG). In addition, the study identified three allelic variants: g.769T>C and g.817G>T in SN and GZ breeds, and g.9760G>C in the three goat breeds. The g.769T>C and g.817G>T loci were closely linked (r² > 0.33). All the single nucleotide polymorphism loci were in Hardy–Weinberg disequilibrium (P < 0.05). Significant associations were found for litter size with all three loci. Therefore, these results suggest that the KITLG gene is a strong candidate gene affecting litter size in goats.     

The imprinted gene DIO3 is a candidate gene for litter size in pigs

Genomic imprinting is an important epigenetic phenomenon, which on the phenotypic level can be detected by the difference between the two heterozygote classes of a gene. Imprinted genes are important in both the development of the placenta and the embryo, and we hypothesized that imprinted genes might be involved in female fertility traits. We therefore performed an association study for imprinted genes related to female fertility traits in two commercial pig populations. For this purpose, 309 SNPs in fifteen evolutionary conserved imprinted regions were genotyped on 689 and 1050 pigs from the two pig populations. A single SNP association study was used to detect additive, dominant and imprinting effects related to four reproduction traits; total number of piglets born, the number of piglets born alive, the total weight of the piglets born and the total weight of the piglets born alive. Several SNPs showed significant (q-value < 0.10) additive and dominant effects and one SNP showed a significant imprinting effect. The SNP with a significant imprinting effect is closely linked to DIO3, a gene involved in thyroid metabolism. The imprinting effect of this SNP explained approximately 1.6% of the phenotypic variance, which corresponded to approximately 15.5% of the additive genetic variance. In the other population, the imprinting effect of this QTL was not significant (q-value > 0.10), but had a similar effect as in the first population. The results of this study indicate a possible association between the imprinted gene DIO3 and female fertility traits in pigs.     

A SNP in the miR-27a gene is associated with litter size in pigs

MicroRNAs (miRNAs) are 20–25 nt, endogenous non-coding RNA molecules that act by binding to the complementary sequence of target messenger RNAs. Many evidences showed that miRNAs were involved in the process of germ proliferation and differentiation. In the present study, miR-27a gene was selected as a candidate gene for litter size due to its biological function, its location near a mummified pigs QTL, and its differentially expressed profile in Large White and Chinese Erhualian PMSG-hCG stimulated preovulatory ovaries. By comparative sequencing of miR-27a gene in Large White and Chinese Meishan pigs, one SNP (T/C) which created an additional HpaII site was detected. Then associations of this SNP with litter size traits were assessed in Large White (n = 142) and DIV (n = 140) pig populations. The statistical analysis demonstrated that AA differed from AB (P < 0.01) and BB (P < 0.05) for total number of piglets born in the first parities, and also differed from AB (P < 0.01) for the number of piglets born alive in all parities (P < 0.05) in DIV pigs. No significant difference was observed between different genotypes in Large White pigs.