猪PRLR和RBP4基因多态性与产仔性能的关系

采用PCR-RFLP方法, 对莱芜黑猪、鲁莱黑猪、里岔黑猪、鲁烟白猪、新沂蒙黑猪5个山东地方/培育猪种和大约克夏、长白、杜洛克3个引进猪种共8个猪种323头繁殖母猪进行PRLR和RBP4基因的多态性检测, 并采用最小二乘法分析其对产仔数影响的遗传效应。结果表明: 两个基因位点在8个猪种的测定群体中均存在多态性, 但山东地方/培育猪种与引进猪种间在基因型频率上存在较大差异。PRLR和RBP4基因对产仔数性状有显著影响(P<0.05), AA均为优良基因型。对于PRLR基因, 山东地方/培育猪种内AA基因型母猪的总产仔数和活产仔数比BB基因型母猪平均多产1.03头和0.89头, 引进猪种中AA基因型母猪比BB基因型母猪平均多产分别为1.26头和1.11头。对于RBP4基因, 山东地方/培育猪种内AA基因型母猪的总产仔数和活产仔数比BB基因型母猪平均多产0.59头和0.51头, 引进猪种中AA基因型母猪比BB基因型母猪平均多产分别为0.72头和0.64头     

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。     

藏猪繁殖性状多基因效应分析

藏猪是我国特有的高原型地方猪种, 具有适应高海拔恶劣气候环境、抗病、耐粗、肉质鲜美等特点, 但繁殖力低。文章以促卵泡素b亚基(FSHb)、雌激素受体(ESR)、促乳素受体(PRLR)和视黄醛结合蛋白4(RBP4)等基因作为繁殖性状主要候选基因, 测定76头藏猪的基因型, 分析单基因和多基因合并对繁殖性状的影响效应。结果说明, 在藏猪群体中, FSHb、ESR和PRLR基因不同基因型繁殖性状差异显著, 优良基因型分别为BB、BB和AA。藏猪RBP4基因只有2种基因型, 对繁殖性状影响不显著。FSHb-ESR-PRLR基因的合并优良基因型为BB-BB-AA, 多基因聚合效应高于单基因效应。     

猪IGF2基因外显子4b的遗传多态性及其遗传效应

采用PCR-SSCP方法检测猪胰岛素样生长因子2(insulin-like growth factor 2,IGF2)基因外显子4b的多态性,并分析其对初生重、断奶重、6月龄重和背膘厚的遗传效应。根据猪IGF2基因的DNA序列(AY044828)设计引物,在exon4b上发现了一个多态性位点,并对纯合子进行测序,发现13位C→A转换,且存在3种基因型(AA、AB、BB)。统计结果表明,3种基因型在各品种中的分布不一致,长白猪与大白猪比较,莱芜猪与大薄莲猪比较,沂蒙黑猪和里岔黑猪比较差异不显著(P>0.05);其他猪种间基因型分布的差异均显著(P<0.05)。固定效应模型分析结果表明,初生重,断奶重和背膘厚基因型间差异显著(P<0.05),而6月龄重基因型间差异不显著(P>0.05)。最小二乘分析结果表明,BB基因型个体同AA和AB、基因型个体比较初生重和断奶重的差异显著(P<0.05),3种基因型在初生重和断奶重的大小排列顺序为AA>AB>BB;AA基因型个体同AB和BB基因型个体比较背膘厚的差异显著(P<0.05),3种基因型在背膘厚的大小排列顺序为BB>AB>AA。因此,推测IGF2基因对个体的生长速度和胴体瘦肉率存在一定的影响,将IGF2基因应用于猪育种过程中的标记辅助选择可以加快猪的育种进程。     

猪产仔数分子标记及其效应分析

初步确定了2个新的猪产仔数分子标记,雌激素受体基因ESR的第8外显子处的ESRB位点、催乳素受体基因的第7外显子的FSHRB位点。通过比较和分析多个产仔数的效应,初步确定了4个有利于产仔数提高的分子标记基因型,基因位点ESR、FSHRB的基因型BB的产仔数显著地高于AB、AA型;位点ESRB、PRLR的基因型AA的产仔数显著地高于AB、BB型;4个基因位点多态性与仔猪生长性能、母猪乳头数不存在显著的影响。     

猪IGF2基因外显子3的遗传多态性及遗传效应分析

采用PCR-SSCP方法检测猪胰岛素样生长因子2(insulin-like growth factor 2,IGF2)基因外显子3多态性,分析其对初生重、断奶重、6月龄重和背膘厚的遗传效应,根据猪IGF2基因的DNA序列(AY044828)设计引物,结果在其扩增片段上检测到多态性,对纯合子进行测序,发现1GF2-ex3-A36T和IGF2-ex3-G109A两个多态性位点,并且这2个多态性位点完全连锁,检测到3种基因型(A36A/G109G.A36T/G109A和T36T/A109A),统计结果表明,基因型在各品种中分布不一致,长白猪和大白猪与莱芜猪、大薄莲猪、沂蒙黑猪和里岔黑猪比较基因型分布差异极显著(P＜0.01);其它猪种间基因型分布差异均不显著(P＞0.05),固定效应模型分析结果表明,初生重和背膘厚基因型间差异显著(P＜0.05),而断奶重和6月龄重基因型间差异不显著(P＞0.05),最小二乘分析结果表明,A36A/G109G基因型个体同A36T/G109A和T36T/A109A基因型个体比较初生重和背膘厚的差异显著(P＜0.05),3种基因型初生重的大小排列顺序为A36A/G109G＜A36T/G109A＜T36T/A109A,背膘厚的大小排列顺序为A36A/G109G＞A36T/G109A＞T36T/A109A.因此,推测IGF2基因对个体的初生重和胴体瘦肉率存在一定的影响,将IGF2基因应用于猪育种过程中的标记辅助选择,将可以改善猪肉品质,加快猪的育种进程.     

猪PRLR基因PCR—SSCP多态性与产仔性能的关联分析

采用PCR-SSCP技术分析了杜洛克猪、长白猪、大白猪、马身猪、山西黑猪和山西白猪等6个品种472个个体催乳素受体基因(PRLR)的多态性,检测到A、B、C 3个等位基因和AA、AB、AC、BB、CC 5种基因型.在马身猪中, B等位基因为优势基因,频率为0.55;其他品种中,优势基因为A等位基因,频率分布在0.79～0.89之间;C等位基因除在大白猪频率略高外(0.20),在其他品种中频率都很低,在0～0.09之间.对AA、BB、CC三种纯合子进行克隆测序和同源序列比较,发现在扩增片段内有6处SNP,都发生在PRLR基因的第8内含子,分别是内含子8第26位、54位和99位的C→T突变,47位和68位的A→G突变,63位的G→A突变.利用最小二乘分析研究了PRLR基因型对母猪头胎总产仔数和产活仔数的影响,结果表明PRLR基因不同基因型母猪的头胎总产仔数和产活仔数差异均不显著.     

母猪哺乳初期的母性行为与催乳素受体基因多态性关系的初探

应用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)方法对民猪和长白猪的催乳素受体(Prolactin receptor, 简称PRLR)基因进行了单核苷酸多态性分析, 以研究PRLR基因影响母猪母性行为性状的可能性。结果发现在PRLR基因的cDNA第1620位点处存在NaeⅠ多态性。测序表明, 该点存在一个T→C的单碱基突变, 属沉默突变。对3种基因型与部分行为性状进行最小二乘分析, 结果表明, AB型母猪与其他两种基因型母猪相比, 表现出较低的侧卧转为其他姿势的频率以及由母猪结束哺乳的频率(P<0.05), 其他行为性状在基因型间不显著。因此, 推测等位基因A可能是影响母猪母性行为的不良基因。     

猪IGF2基因的遗传多态性及其遗传效应分析

采用PCR-SSCP方法检测胰岛素样生长因子2 (insulin-like growth factor 2, IGF2)基因外显子7, 8, 9的多态性, 并分析其对初生重、断奶重、6月龄重和6月龄背膘厚的遗传效应。根据猪IGF2基因的DNA序列(AY044828)设计3对引物, 结果在Ex8引物对扩增的片段上发现了多态性, 并对纯合子进行测序, 发现exon8的53位存在C→T转换, 且检测到3种基因型(AA、AB、BB)。统计结果表明, 3种基因型在各品种中的分布不一致, 长白猪与大白猪比较, 莱芜猪与大薄莲猪比较, 沂蒙黑猪和里岔黑猪比较差异不显著(P > 0.05); 其他猪种间基因型分布的差异均显著(P < 0.01)。固定效应模型分析结果表明, 初生重和6月龄背膘厚基因型间差异显著(P < 0.05), 而断奶重和6月龄重基因型间差异不显著(P > 0.05)。最小二乘分析结果表明, BB基因型个体同AA和AB基因型个体比较初生重的差异显著(P < 0.05), 3种基因型在初生重的大小排列顺序为AB > AA > BB; AA基因型个体同AB和BB基因型个体比较6月龄背膘厚的差异显著(P < 0.05), 3种基因型在6月龄背膘厚的大小排列顺序为BB > AB > AA。因此, 推测IGF2基因对个体的初生重和胴体瘦肉率存在一定的影响, 将IGF2基因应用于猪育种过程中的标记辅助选择可以加快猪的育种进程。     

猪MyoG基因内含子1的一个遗传多态性及其遗传效应分析

以长白猪(73),大白猪(68),沂蒙黑猪(57)和莱芜猪(83)为研究对象,采用PCR-SSCP方法 对猪MyoG基因遗传多态性进行分析,并研究基因型与初生重、日增重、肌肉嫩度和背膘厚的相关性.根据猪MyoG 基因的DNA序列（M14331）设计引物,结果在内含子1扩增的片段上发现了一个多态性,检测到2个等位基因(A、B),3种基因型（AA、AB、BB）,并对纯合子进行测序,发现2　943位G→C突变.基因型在不同猪种分布的多重比较,结果表明,大白猪与长白猪、沂蒙黑猪和莱芜猪比较差异显著（P<0.05）,莱芜猪与长白猪和沂蒙黑猪比较差异显著（P<0.05）,长白猪与沂蒙黑猪比较差异不显著（P>0.05）.固定效应模型分析结果表明,初生重及嫩度基因型间差异显著（P<0.01）,而日增重及背膘厚基因型间差异不显著（P>0.05）.最小二乘分析结果表明,BB基因型个体与AA基因型个体比较肌肉嫩度的差异显著（P<0.05）,AA基因型个体与AB和BB基因型个体比较背膘厚的差异显著（P<0.05）.因此,推测MyoG基因对猪肉品质、生长速度及背膘厚存在一定的影响,将 MyoG基因应用于猪育种过程中的标记辅助选择将可以改善猪肉品质,提高生长速度,加快猪的育种进程.     

Associations between the prolactin receptor gene polymorphism and reproductive traits of boars

The prolactin receptor gene (PRLR), located on chromosome 16 in pigs, is a candidate gene for reproductive traits. The experiment was aimed to detect the DNA mutations in this gene and to find probable relations between the genotype and some reproductive traits in boars. The polymorphism in the PRLR gene was identified by PCR-RFLP method using specific primers and the restriction enzyme AluI. In total 229 boars of various breeds were genotyped. The frequency of allele A was estimated at 0.62 and allele B at 0.38. Genotype AA was found at a frequency of 0.45, AB at 0.35 and BB at 0.20. We found associations between PRLR genotype and ejaculate volume, sperm concentration, percentage of live sperm, and number of live sperm in the ejaculate (P < 0.01).     

藏猪3个繁殖性状主效基因多态性研究

藏猪是我国高海拔特有猪种,为了解藏猪繁殖性能的遗传潜力和基因多样性,利用PCR－RFLP技术测定了202头藏猪ESR、FSHβ和PRLR 3个繁殖性状主效基因位点的基因型多态性,并与文献报道的国内外猪种进行比较。结果显示藏猪群体ESR、FSHβ和PRLR优势基因型分别为BB型、AB型和AA型,3个位点基因型分布均符合哈迪－温伯格平衡。藏猪群体3个繁殖性状主效基因位点都有报道的有利基因型,且有利等位基因频率较高,说明藏猪在这3个基因位点可能具有优良繁殖性能的遗传潜力。     

Prolactin Receptor as a Candidate Gene for Prolificacy of Small Tail Han Sheep

DNA polymorphism of the ovine prolactin receptor gene (PRLR) was investigated and used to study its effect on litter size in sheep. By means of PRLR gene sequence homology between sheep and human, three primer pairs were designed for polymerase chain reaction (PCR) amplification within intron 1 and exon 10 of the PRLR gene in sheep. In these parts of the gene the single nucleotide polymorphisms were detected by PCR-single strand conformation polymorphism (SSCP) in 314 Small Tail Han ewes. These poly-morphisms were used to study the associations with litter size. The results indicated that there were three genotypes (AA, AB and BB) detected by three primer pairs. For three primer pairs the frequency of allele A was 0.96, 0.79, 0.68; and the frequency of allele B was 0.04, 0.21, 0.32, respectively. The frequency of genotype AA was 0.93, 0.62, 0.51; the frequency of genotype AB was 0.06, 0.34, 0.34; the frequency of genotype BB was 0.01, 0.04, 0.15, respectively. The Small Tail Han ewes with genotype BB or AB had 0.64–0.76 or 0.44–0.54 more lambs than those with genotype AA, respectively. These results preliminarily showed that the prolactin receptor locus is either a major gene that influences the prolificacy in Small Tail Han sheep or is in close linkage with such a gene.     

母猪生殖器官大小和产仔数的分子遗传基础

采用单核苷酸多态分析技术（SNP）分析母猪3个生殖激素受体基因（ESR、PRLR和FSHR）的变异,屠宰103头母猪并测定其生殖器官大小;统计母猪的产仔数;利用SAS或SPSS分析软件分析基因变异与母猪的生殖器官大小,产仔数多少的连锁关系,以探讨母猪生殖器官大小和产仔数多少的分子遗传基础,结果表明,如母猪携带的基因型为位点,ESR的BB型,位点FSHRB的BB型,位点ESRB的AA型,位点PRLR的AA型,则母猪的生殖器官较大,产仔数也较多;在位点ESRB或位点PRLR中,带有AA基因型母猪不仅产仔数显著地高于AB、BB型,而且生殖器官也显著大于AB、BB型;在位点ESR和FSHRB中,带有BB基因型母猪的生殖器官,产仔数显著高于带有AB或AA型母猪。     

Ontogenic expression pattern and genetic polymorphisms of the retinol-binding protein 4 (RBP4) gene in Erlang mountainous chickens

Retinol-binding protein 4 (RBP4) is the only circulatory transport protein for vitamin A. Based on the essential role of vitamin A in chicken reproduction, we measured RBP4 mRNA abundance in Erlang mountainous chickens. We also identified and analyzed the gene polymorphism and its effect on reproduction traits among 349 chickens. The expression of RBP4 mRNA showed specific developmental changes and striking differences among tissues. The mRNA abundance was greatest (P < 0.05) in the liver, intermediate in the ovary, kidney, small intestine, oviduct and heart, and lowest in the hypothalamus and pituitary, as compared to all other tissues (P < 0.05). We detected one single nucleotide polymorphism (g.19942455C>G) in intron 2 of the RBP4 gene. Three genotypes (CC, CG and GG) were identified, with a significant effect of genotype on the age at first egg (AFE), first egg weight (FEW), total eggs at 300 days (TE300), highest continuous laying days (HCLD) and average laying interval (ALI). The GG genotype, where chickens display earlier AFE, more TE300, longer HCLD and shorter ALI, would be genetically advantageous and its selection may improve reproduction traits. These results suggested that the RBP4 gene might play an important role in reproduction traits in chickens.     

Novel SNPs of the Bovine PRLR Gene Associated with Milk Production Traits

The single nucleotide polymorphisms (SNPs) within exon 10 of the prolactin receptor gene (PRLR) were detected in Chinese Holstein cows using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing methods, and their genetic effects on milk production traits were evaluated in this study. Two newly detected SNPs (g.9206G→A and g.9681C→T) caused amino acid variations E378K and A536V, respectively, which were then preliminarily predicted at the topological level. Statistical results indicated that the two SNPs were significantly associated with milk yields, and cows with the combined genotype GGCC showed superior milk performance. A putative phosphorylation site was identified at residue 378K ([ST]-×-[RK]), which offers a partial explanation for the associations. These results suggest that the two novel SNPs within exon 10 of the PRLR gene associated with milk production traits are useful genetic markers in a selection program for Holstein dairy cattle.