辽宁绒山羊IGF-Ⅰ基因5′调控区多态性与产绒性状相关

根据表型性状选取少量辽宁绒山羊个体,直接进行类胰岛素生长因子-Ⅰ(IGF-Ⅰ) 基因5′调控区克隆测序以确定单核苷酸多态(SNP)位点,共发现4个SNPs,分别是G→C (388 bp)、A→G (668 bp)、A→C (719 bp)、G→A (752 bp)的突变,导致5′调控区305～800 bp中比野生型个体减少一个CdxA转录因子结合位点,但C/EBP的值 (89.2)高于野生型 (88.5)．然后通过引入错配碱基创造酶切位点技术和多聚酶链反应-限制性片段长度多态性 (PCR-RFLP)方法,对520只辽宁绒山羊进行基因型检测,结果表明,每个SNP位点在本群体中都有AA (野生型)、AB和BB (突变型) 三种基因型,且4个SNPs位点共有13种单倍型组合．将不同SNP的基因型及单倍型组合与绒产量、绒纤维细度和绒纤维长度进行关联分析发现,SNP2位点的AA基因型绒纤维细度极显著低于AB型和BB型 (P < 0.01),而SNP4位点AA基因型产绒量显著高于AB型和BB型 (P < 0.05),单倍型组合H7H7与产绒量和绒纤维细度均有显著相关(P < 0.05)．IGF-Ⅰ基因可能是影响绒山羊产绒性状的主要候选基因．     

LALBA基因SNP与内蒙古白绒山羊经济性状的关联

利用PCR-SSCP和DNA测序技术检测452份内蒙古白绒山羊α-乳白蛋白(LALBA)基因单核苷酸多态性(SNP), 并分析SNP与产绒量、绒厚、绒长和体重性状的关联。结果表明, 仅P2引物位点存在SSCP多态, 其外显子3区域存在1个突变位点: M63868:g.1897T>C。内蒙古白绒山羊群体LALBA基因M63868:g.1897位点以TT型为主, T等位基因频率为0.983, 且处于Hardy-Weinberg平衡状态(P>0.05)。方差分析表明, LALBA基因M63868:g.1897位点多态仅与产绒量存在显著相关(P=0.017); 1897位点TC基因型个体产绒量比TT基因型个体多产绒142.68 g, 高26.21%, 且差异显著(P<0.05)。因此, TC基因型可作为山羊产绒性状标记辅助选择的有效DNA标记。     

辽宁绒山羊IGF-Ⅰ基因5''调控区多态性与产绒性状相关

根据表型性状选取少量辽宁绒山羊个体,直接进行类胰岛素生长因子-Ⅰ(IGF-Ⅰ)基因5'调控区克隆测序以确定单核苷酸多态(SNP)位点,共发现4个SNPs,分别是G→C(388 bp)、A→G(668 bp)、A→C(719 bp)、G→A(752 bp)的突变,导致5'调控区305～800 bp中比野生型个体减少一个CdxA转录因子结合位点,但C/EBP的值(89.2)高于野生型(88.5).然后通过引入错配碱基创造酶切位点技术和多聚酶链反应-限制性片段长度多态性(PCR-RFLP)方法,对520只辽宁绒山羊进行基因型检测,结果表明,每个SNP位点在本群体中都有AA(野生型)、AB和BB(突变型)三种基因型,且4个SNPs位点共有13种单倍型组合.将不同SNP的基因型及单倍型组合与绒产量、绒纤维细度和绒纤维长度进行关联分析发现,SNP2位点的AA基因型绒纤维细度极显著低于AB型和BB型(P<0.01),而SNP4位点AA基因型产绒量显著高于AB型和BB型(P<0.05),单倍型组合H7H7与产绒量和绒纤维细度均有显著相关(P<0.05).IGF-Ⅰ基因可能是影响绒山羊产绒性状的主要候选基因.     

辽宁绒山羊IGF-Ⅰ基因5＇调控区多态性与产绒性状相关

根据表型性状选取少量辽宁绒山羊个体,直接进行类胰岛素生长因子-Ⅰ（IGF-Ⅰ）基因5＇调控区克隆测序以确定单核苷酸多态（SNP）位点,共发现4个SNPs,分别是G→C（388bp）、A→G（668bp）、A→C（719bp）、G→A（752bp）的突变,导致5＇调控区305～800bp中比野生型个体减少一个CdxA转录因子结合位点,但C/EBP的值（89.2）高于野生型（88.5）.然后通过引入错配碱基创造酶切位点技术和多聚酶链反应-限制性片段长度多态性（PCR-RFLP）方法,对520只辽宁绒山羊进行基因型检测,结果表明,每个SNP位点在本群体中都有AA（野生型）、AB和BB（突变型）三种基因型,且4个SNPs位点共有13种单倍型组合.将不同SNP的基因型及单倍型组合与绒产量、绒纤维细度和绒纤维长度进行关联分析发现,SNP2位点的AA基因型绒纤维细度极显著低于AB型和BB型（P〈0.01）,而SNP4位点AA基因型产绒量显著高于AB型和BB型（P〈0.05）,单倍型组合H7H7与产绒量和绒纤维细度均有显著相关（P〈0.05）.IGF-Ⅰ基因可能是影响绒山羊产绒性状的主要候选基因.     

湖羊、东湖杂种羊POMC基因外显子3单核苷酸多态性及其与生长性状的关联分析

阿黑皮素原(Pro-opiomelanocortin, POMC)在动物采食和能量平衡调控中发挥重要作用, 文章对绵羊POMC基因外显子3进行扩增和测序, 筛选多态性位点, 并分析多态位点与湖羊和东弗里生×湖羊杂种羊生长性状的相关性。测序后发现湖羊POMC基因外显子3有2个单碱基突变(g.273 T/C和g.456 G/A), 根据273位点处发生的T/C突变, 建立PCR-RFLP分析方法, 并对162只湖羊和130只东湖杂种羊进行检测分析。结果发现, 在湖羊群体中检测到TT(0.469)、TC(0.438)和CC(0.093)3种基因型, 而在东湖杂种羊群体中仅检测到TT(0.754)和TC(0.246)两种基因型。POMC基因外显子3的273位点多态性与生长性状的相关性研究结果显示：湖羊群体中CC基因型个体的2月龄断奶重、4月龄尻高及TC基因型个体4月龄体长和管围均显著高于TT型个体(P<0.05); CC基因型个体的4月龄重、6月龄重极显著高于TT和TC基因型个体(P<0.01); CC基因型个体的4月龄体高和体长极显著高于TT型个体(P<0.01), 且显著高于TC基因型个体(P<0.05)。此外, CC型个体的管围极显著高于TT基因型个体(P<0.01)。东湖杂种羊群体中TC基因型个体的2月龄断奶重、4月龄重及4月龄体高、体长、胸深和管围都显著高于TT型个体(P<0.05), TC型个体的6月龄重极显著高于TT型个体(P<0.01)。研究结果表明, POMC基因外显子3与绵羊生长性状相关, C等位基因对体重及体尺性状的增加更有利。该结果为进一步探讨POMC基因作为绵羊生长性状的辅助选育标记奠定了基础。     

IGFBP-3基因多态性及其与中国美利奴羊部分羊毛性状的关联性分析

采用PCR-SSCP方法对中国美利奴羊和哈萨克羊中IGFBP-3基因的多态性进行了检测, 并对不同基因型与中国美利奴羊部分羊毛性状间的关联性进行了分析。结果在位于内含子1区的一段178 bp的扩增产物经SSCP分析后出现了3种基因型, 基因型AA、AB和BB及等位基因A、B在中国美利奴羊中的频率分别为0.70、0.24、0.06和0.82、0.18; 在哈萨克羊中的频率分别为0.87、0.13、0.00和0.93、0.07。序列分析发现: 在该序列的122位碱基表现多态性 (g.122 G>T)。所研究的两个群体在该位点上均处于Hardy-Weinberg不平衡状态(P<0.01)。不同基因型对部分羊毛性状有一定的影响: 不同基因型个体在剪毛后体重和净毛率上没有明显差异。AA、AB及BB基因型个体的羊毛伸直长度逐渐变短, 其中AA与AB基因型之间差异极显著(P<0.01)。AA型个体的剪毛量和羊毛密度要明显低于AB型(P<0.01)和BB型个体(P<0.05); 羊毛纤维直径则明显高于AB型(P<0.01)和BB型(P<0.05)个体。     

尼罗罗非鱼ghrelin基因的多态性及其与生长性状相关SNP位点的筛选

为了研究尼罗罗非鱼(Oreochromis niloticus)生长激素促分泌素基因(ghrelin)的多态性及其与生长的相关性, 研究以两个尼罗罗非鱼群体(快长群体和基础群体)的DNA样本各40份为模板, 通过PCR扩增和测序获得ghrelin基因序列。通过Dnasp v5和MEGA 5.0分析序列多态性、筛选有效SNP 位点; 采用Snapshot法对两个群体子代ghrelin基因中SNP位点进行基因分型, 然后分析SNP位点基因型与生长性状的相关性。结果表明, 快长群体ghrelin基因中的单核苷酸变异位点数(S)比基础群体要少, 而核苷酸多态性(Pi)和平均核苷酸差异数(K)要略高于基础群体。共筛得3个有效SNP 位点(S1、S2和S3), 均分布于第1个内含子中。遗传结构分析表明, 3个SNP 位点在两个群体的子代中均为低度多态性位点(PIC0.25), 但处于Hardy-Weinberg平衡(P0.05);快长群体子代中3个SNP 位点的观测杂合度、期望杂合度和多态信息含量等遗传多样性参数均小于基础群体子代的相应值, 3个SNP 位点的遗传多样性参数、基因型和基因频率在同一群体中高度一致, SNP 位点之间完全连锁。两个群体子代中3个SNP 位点处的优势基因型相同, 但快长群体子代中优势基因型频率要明显大于基础群体子代中相应基因型频率。对两个群体子代的生长性状与SNP基因型进行关联性分析的结果表明,尼罗罗非鱼个体的多项生长指标(体重、体长、体高、头长和尾柄高等)在不同基因型中存在显著差异(S1:GG AG, S2:TT AT, S3:AA AT)(P0.05)。D1双倍型(S1:GG, S2:TT, S3:AA)所对应的尼罗罗非鱼个体的多项生长指标(体重、体长、体高、头长和尾柄高等)显著高于D2双倍型(S1:AG, S2:AT, S3:AT)。以上结果表明, 尼罗罗非鱼ghrelin基因3个SNP 位点完全连锁, D1双倍型与快长性状密切相关, 可作为尼罗罗非鱼分子标记辅助育种的候选标记。     

中华绒螯蟹MSTN基因SNPs多态性及与生长性状的关联分析

为研究中华绒螯蟹(Eriocheir sinensis)肌肉生长抑制素基因(myostatin, MSTN)的多态性及其与生长性状的相关性, 对中华绒螯蟹3个群体(育种群体、大赛群体、野生群体)共321个个体MSTN基因的多态性进行筛选, 发现该基因的第1外显子存在3个多态性SNP位点(S1: C714T; S2:G729A; S3:G753T), 均为处于Hardy-Weinberg平衡(P>0.05)的中、高度多态性位点。利用一般线性模型分析3个位点及其基因型组合与生长性状的相关性, 发现S1位点对中华绒螯蟹的体重和壳长等生长性状有显著影响(P≤0.05), 而其余2个位点与生长性状无显著关联性。结果表明S1位点的TT基因型对中华绒螯蟹的生长最为有利, 可作为分子标记辅助育种的候选标记。     

鸡MD基因5′侧翼区多态性与鸡生长和体组成性状的相关研究(英文)

苹果酸脱氢酶(MalateDehydrogenase,MD)是一种氧化还原性酶,参与体内多种能量代谢反应。它可以催化苹果酸氧化脱羧生成丙酮酸和CO2,并使NADP+还原成NADPH,NADPH是脂肪酸合成所必需的载体,棕榈酸可以利用生成的NADPH来合成长链脂肪酸,MD的活性与脂肪酸合成效率之间存在密切的相关,MD也参与体内骨骼肌、心肌的能量代谢,并对肌纤维的生长有一定的调节作用。根据鸡MD基因的5′侧翼区序列设计一对引物,用直接测序的方法在侧翼区检测多态性位点,在235bp(GenBank登录号:U49693)处发现一个SNP位点,此位点是一个限制性内切酶(SphⅠ酶)发生变化的位点。以东北农业大学高低脂双向选择系的第8世代肉鸡和东农F2资源群体为实验材料,用PCR-RFLP的方法进行基因型分析,建立适合的统计模型,进行基因型与生长和体组成性状的相关分析。结果表明:在高低脂系第8世代肉鸡中AA基因型个体的腹脂重和腹脂率显著高于BB基因型个体(P<0.05);BB基因型个体的大胸肌重和大胸肌率显著高于AA基因型个体(P<0.05)。在东农F2资源家系中BB基因型个体的大胸肌重和大胸肌率显著高于AA和AB基因型个体(P<0.05);AA基因型个体的肝脏重和肝脏率显著高于BB基因型个体(P<0.05)。综上所述,MD基因可能是影响鸡生长和体组成性状的主效基因或与控制生长和体组成性状的主效基因相连锁。     

兔成纤维细胞生长因子5(FGF5)基因SNP及其与产毛量的相关分析

通过PCR产物直接测序的方法, 对荥经长毛兔、天府黑兔以及加利福尼亚兔的FGF5基因外显子1和外显子3进行单核苷酸多态性分析。在外显子1的217位(位点A)检测到由TCT三碱基插入引起的移码突变, 在外显子3的59位(位点B)和3位(位点C)分别发生了错义突变由T→C和同义突变由T→C。通过计算发现各位点不同的基因型和等位基因频率在3个兔品种中存在较大的差异, 位点A、B在长毛兔和肉兔中均有各自的优势基因型和等位基因。各位点基因型与产毛量的最小二乘分析表明, 位点A各基因型的个体在产毛量上差异不显著(P＞0.05), 位点B各基因型个体产毛量的差异极显著(P＜0.01), 位点C各基因型个体产毛量的差异显著(P＜0.05)。初步推断FGF5基因可能是影响长毛兔产毛量潜在的主效基因或者与主效基因连锁, 可作为长毛兔产毛性状连锁分析的候选遗传标记。     

A novel genetic variant of the goat Six6 gene and its association with production traits in Chinese goat breeds

We looked for novel genetic variations within the Six6 gene by PCR-SSCP, DNA sequencing and forced RFLP-PCR and estimated their associations with production traits in 2132 goats of eight indigenous Chinese breeds. A novel single nucleotide polymorphism (NM_001104993.1: g.232T>C) within the goat Six6 gene was identified. The frequencies of allele "C" varied from 0.8621 to 1.000, which were in Hardy-Weinberg equilibrium. Genotype and allele frequencies were found to be significantly different in the breeds. Association analysis revealed a significant relationship between genotypes and cannon circumference in Hainan black goats (P = 0.047); adult individuals with genotype CT showed higher cannon circumference than those with genotype CC. Another significant association of genotypes with five-year-old fiber length was found in Inner Mongolia white cashmere goats (P = 0.002). In addition, individuals with genotype CT had longer fiber length than those with genotype CC. The data revealed that the Six6 gene positively affects growth traits and cashmere traits. Polymorphism of Six6-PstI could be useful as a DNA marker for goat breeding and genetics via marker-assisted selection.     

Cashmere production,skin characteristics,and mutated genes in crimped cashmere fibre goats

A subpopulation of Yanshan cashmere goats with crimped fibre has emerged in a closed population in recent years, but little is known about differences in cashmere production performance, skin characteristics, and fibre-style-related genes between goats with different cashmere fibre styles. Therefore, the aim of this study was to investigate fibre characteristics, cashmere yield, hair follicle traits, and fibre-style-related genes in cashmere goats with the two cashmere fleece styles—non-crimped and crimped. Based on the cashmere fibre type, 80 six-month-old female Yanshan cashmere goats were used in this study: 40 goats with non-crimped fleece (NCF) and 40 with crimped fleece (CF). The growth performance and cashmere production of the goats were recorded. Skin samples were collected to determine hair follicle traits and gene sequencing. The results indicated that there were no differences in initial live weight, final live weight, average daily feed intake, and average daily gain between the two groups of goats (P > 0.05). The total yield of cashmere and the stretched length of fibre of the CF goats were higher (P < 0.01 and P < 0.05, respectively) and fibre diameter was lower (P < 0.05) than that of the NCF goats. There were no between-group differences in the density and activity of primary and secondary hair follicles, secondary-to-primary fibre ratio, depth of primary follicles, or epidermal thickness. However, the depth of secondary follicles and dermal thickness were higher (P < 0.05) in NCF goats than in CF goats. There were mutations in the KRT5, KAP8, KRT8, KRT74, KRT34, KRT1, KRT71, KRT6A, KAP6, KRT81, and KRT83 genes, four of which caused amino acid changes. The allele and genotype frequencies of base mutations in the KRT5, KAP8, KRT34, KRT1, KRT6A, KRT81, and KRT83 genes were different in the NCF and CF goats (P < 0.05). The distribution and content of the secondary structure elements and tertiary structures of proteins differed between the wide-type and mutated KRT1 and KRT6A proteins. KRT1, KRT6A, KRT71, and TGFα mRNA expression levels were significantly higher in CF goats than in NCF goats (P < 0.05). It is concluded that cashmere goats that have fleece with crimped fibres produce a greater yield of fleece with finer diameter fibres than those with conventional straight cashmere fibres. These differences in fibre properties may be associated with mutations in the genes coding for KRT1 and KRT6A.     

Effect of melatonin administration to lactating cashmere goats on milk production of dams and on hair follicle development in their offspring

Melatonin treatment in adult cashmere goats can increase cashmere yield and improve cashmere fibre quality by inducing cashmere growth during cashmere non-growth period, of which time cashmere goats are in the mid and late stages of lactation. However, whether melatonin treatment in adult cashmere goats affects their offspring’s growth performance remains unknown. Therefore, the objectives of the current study were to determine the effects of melatonin treatment in adult cashmere goats on cashmere and milk production performance in dams and on hair follicle development and subsequent cashmere production in their offspring. Twenty-four lactating Inner Mongolian Cashmere goat dams (50 ± 2 days in milk, mean ± SD) and their single-born female offspring (50 ± 2 days old, mean ± SD) were randomly assigned to one of two groups supplemented with melatonin implants (MEL; n = 12) or without (CON; n = 12). The melatonin implants were subcutaneously implanted behind the ear at a dose of 2 mg/kg live weight on two occasions – 30 April and 30 June 2016. The results demonstrated that melatonin treatment in adult cashmere goats increased cashmere production and improved cashmere fibre quality as indicated by greater cashmere yield, longer cashmere fibre staple length, finer cashmere fibre diameter and thicker cashmere fibre density. The milk fat content was higher in MEL compared with CON cashmere goats. The daily yields of milk production, milk protein and milk lactose were lower in MEL compared with CON cashmere goats. Serum melatonin concentrations were greater, serum prolactin concentrations were lower and milk melatonin concentrations and yields were greater in MEL compared with CON cashmere goats. With regard to offspring, there were no differences in cashmere yield, fibre staple length, fibre diameter and fibre density at yearling combing, and the primary and secondary hair follicles population and maturation between treatments. In conclusion, melatonin treatment in adult cashmere goats during cashmere non-growth period is a practical and an effective way in cashmere industry as indicated by not only increasing cashmere yield and improving cashmere fibre quality in adult cashmere goat dams but also having no impairment in hair follicle development and the subsequent cashmere production in their single-born offspring.     

山羊GOLA-DQA2基因多态性与血液免疫性状的相关分析

文章采用PCR-RFLP技术对莱芜黑山羊、波尔山羊、鲁波山羊3个山羊种群的GOLA-DQA2基因外显子2进行遗传多态性研究, 并对其血液免疫指标的效应进行分析。结果表明, 3个山羊种群共检测到4种基因型, 由3个等位基因控制; GOLA-DQA2基因外显子2的第77、79、80和169位的碱基表现出多态性; 多数血液免疫指标品种效应是主要效应; 鲁波山羊中, AB基因型的红细胞计数、白细胞计数分别显著高于BB基因型、BC基因型(P<0.05); AB基因型的红细胞压积显著高于BB、BC 基因型(P<0.05); BC基因型的噬中性粒细胞比率显著高于BB基因型(P<0.05); 波尔山羊和莱芜黑山羊中, 基因型与血液免疫指标之间也有一定的相关性, 但没有达到显著水平。由上述结果初步推测, 在鲁波山羊中, AB、BC基因型是影响红细胞计数、白细胞总数、噬中性粒细胞比率等血液免疫指标的重要因素。研究结果揭示GOLA-DQA2基因与血液免疫指标之间有一定的相关性, 可为山羊的抗病育种提供一定的参考。     

A PstI polymorphism at 3′UTR of goat POU1F1 gene and its effect on cashmere production

POU1F1 is a positive regulator for prolactin (PRL) whose metabolites may directly or indirectly affect some aspects of the hair growth cycle, therefore, POU1F1 gene is an important candidate gene for cashmere traits selection through marker-assisted selection (MAS). Hence, in this study, the PCR-RFLP method was applied to detect a T>C transition determining a PstI polymorphism at the 3′UTR of POU1F1 locus and evaluate its associations with cashmere traits in 847 Inner Mongolia White Cashmere goats. In the analyzed population, the allelic frequencies for the T and C alleles are 0.959 and 0.041, respectively and the genotypic frequencies are in Hardy-Weinberg equilibrium (P > 0.05). Moreover, significant statistical relationships between the PstI polymorphism of POU1F1 gene and goat cashmere yields were found (*P < 0.05). When compared with TC genotype, TT genotype was associated with superior cashmere yields in 2, 4, and 5 years old individuals, as well as with average cashmere yield. Hence, TT genotype is suggested to be a molecular marker for senior cashmere yield. X. Y. Lan and J. H. Shu have contributed equally to this article.     

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。     

Analysis of genetic variability at codon 42 within caprine <Emphasis Type="Italic">prion protein</Emphasis> gene in relation to production traits in Chinese domestic breeds

In this study, genetic variability at codon 42 within prion protein (PRNP) gene and its associations with production traits were investigated in 2002 goats from four Chinese domestic breeds. The frequencies of allele “A” ranged from 0.353 to 0.562 in analyzed goat breeds with Hardy–Weinberg equilibrium (P > 0.05) except Xinong Sannen (XNSN) dairy breed. The establishment of relationships between different genotypes and growth traits was performed in Inner Mongolia white Cashmere (IMWC) breed and revealed an association of the polymorphism with body weight at 7-year-old goats (P = 0.033). The individuals with genotype GG showed heavier body weight than those with genotype AA. Moreover, association analysis detected two significant associations between different genotypes and cashmere yield and fiber length in IMWC breed (P = 0.009, P = 0.048, respectively). In addition, three significant associations of different genotypes with density of milk (a.m. and p.m.), solids-not-fat of milk (P = 0.013, P = 0.009 and P = 0.002), respectively, were found in XNSN breed. Genotype GG had better milk quality than others. These findings suggested that the polymorphism of codon 42 within PRNP was a useful DNA marker for eliminating or selecting excellent individuals in relation to production traits in marker-assist selection breeding of goat.     

IGFBP3基因多态性与秦川牛部分屠宰性状的相关性 Polymorphisms of Insulin-like Growth Factor Binding Protein 3 Gene and Its Associations with Several Carcass Traits in Qinchuan Cattle

以IGFBP3基因作为秦川牛（Bos taurus）部分屠宰指标的侯选基因,在对60头秦川牛的IGFBP3基因进行PCR-RFLP和序列分析的基础上,对秦川牛群体中IGFBP3基因座等位基因和基因型频率的分布及其与秦川牛部分屠宰性状的关系进行了分析。结果发现,在秦川牛群体中,651 bp的PCR 产物经过限制性内切酶HaeIII消化后,表现出3种基因型,其中等位基因A、B及3种基因型AA、AB、BB的频率分别为0.84、0.16和070、0.28、0.02。经序列分析发现,第299位的C→A颠换（GGCC变成了GGAC）导致了1个HaeIII限制性酶切位点的丢失而产生了该基因座多态性。在所研究的群体中,该多态基因座处于Hardy-Weinberg平衡状态（P＞005）。对13头24月龄秦川牛进行屠宰分析,发现不同基因型对秦川牛部分屠宰指标有一定影响,AA、AB及BB型个体的屠宰率、净肉率及西冷、牛柳、眼肉和嫩肩肉的产率逐渐降低,但差异不显著（P＞0.05）;AA型个体的眼肌面积大于BB型个体（P＜0.05）,AB型和BB型个体胴体脂肪含量高于AA型个体（P＜0.01）。 Abstract:DNA samples from 60 Qinchuan cattle (Bos taurus) were analyzed with PCR-RFLPs and sequencing for insulin-like growth factor binding protein 3 (IGFBP3) gene.Fragments of 651 bp were amplified with two primers and the products of PCR were digested with restriction endonuclease HaeIII.The produced fragments showed three genotypes,namely AA,AB and BB after electrophoresis.Frequencies of the genotype AA,AB,BB and allele A,B were 0.7,0.28,0.02,and 0.84,0.16,respectively.Sequence analysis showed that a transversion of C→A at 299 nt resulted in loss of the cleaved site of restriction endonuclease HaeIII and produced this polymorphism.This polymorphic locus of IGFBP3 gene was at Hardy-Weinberg equilibrium (P＞0.05).The genotypes of AA,AB,BB slightly affected several slaughter and carcass traits of Qinchuan cattle.Dressing percentage,net meat percentage,striplion percentage,tenderloin percentage,ribeye percentage and tender shoulder percentage were decreased with the genotypes of AA,AB and BB in Qinchuan cattle,but it was not significant (P＞0.05).Average ribeye area in individuals of AA genotype was significantly higher than that in individuals of BB genotype (P＜0.05),and beef fat content in individuals of genotype AB and BB was significantly higher than that in individuals of AA genotype (P＜0.01).     

Polymorphism of bone morphogenetic protein 4 gene and its relationship with litter size of Jining Grey goats

Two pairs of primers (P1 and P2) were designed to detect single nucleotide polymorphisms of exon 2 and intron 2 of bone morphogenetic protein 4 (BMP4) gene in both high fecundity breed (Jining Grey goat) and low fecundity breeds (Boer, Angora and Inner Mongolia Cashmere goats) by single strand conformation polymorphism. Results showed that no polymorphism was detected for exon 2 (primer P1) of BMP4 gene in four goat breeds. For intron 2 (primer P2), three genotypes (AA, AB and BB) were detected in Jining Grey and Inner Mongolia Cashmere goats, two genotypes (AB and BB) in Angora goats, and only one genotype (AA) in Boer goats. Sequencing revealed one mutation (2203G>A) of BMP4 gene in the genotype BB in comparison to the genotype AA. The differences of litter size between AA, AB and BB genotypes were not significant (P > 0.05) in Jining Grey goats. A pair of primer (P3) was designed to detect polymorphism in the 3' flanking region of BMP4 gene that contained dinucleotide repeated sequence (CA) in the four goat breeds by microsatellite analysis. For primer P3, three genotypes (CC, CD and DD) were detected in four goat breeds. Sequencing revealed one more CA dinucleotide in genotype DD than in genotype CC. The Jining Grey does with genotype CC had 0.55 (P < 0.05) or 0.72 (P < 0.05) kids more than those with genotype CD or DD. These results preliminarily indicated that allele C of BMP4 gene is a potential DNA marker for improving litter size in goats.