猪数量性状位点的定位和候选基因研究进展

数量性状位点(QTL)的定位是鉴别家畜控制重要经济性状基因的第一步。分子生物学技术的飞速发展及其应用,为人们在DNA水平上研究猪重要经济性状的遗传机制奠定了坚实的基础。本文综述了影响猪繁殖、生长发育、肉质等主要经济性状的QTLs定位和候选基因研究进展情况。     

母猪杀婴行为QTL定位及其候选基因研究进展

已有研究表明,遗传因素对母猪杀婴行为的产生起重要作用。本文对母猪杀婴行为及其影响因素、母猪杀婴行为数量性状位点（QTLs）和相关候选基因的研究进展进行了综述。     

猪腹股沟/阴囊疝易感位点定位及其候选基因研究进展

腹股沟/阴囊疝是猪最常见的遗传缺陷之一,每年给世界养猪业造成巨大的经济损失,其发病率一般在1.7%~6.7%,但在不同的品种和群体间有较大差异。已有研究表明,猪腹股沟/阴囊疝的发生主要受遗传因素影响,本文综述了猪腹股沟/阴囊疝疾病易感位点和相关侯选基因的研究进展,旨在为系统解析猪猪腹股沟/阴囊疝的分子遗传及病理机制提供参考,并对发展抗猪腹股沟/阴囊疝分子育种技术提出展望。     

猪13号染色体上脂肪沉积相关QTL定位与候选基因研究进展

目前已有多个影响脂肪沉积的QTL定位于猪13号染色体上。作者综述了猪13号染色体脂肪沉积相关QTL的定位情况，并对该染色体上影响脂肪沉积的基因进行了介绍，以希望通过比较基因组学和位置候选克隆的方法，寻找猪脂肪沉积相关的候选基因，进而进行连锁分析或关联研究，找到适合在育种实践中进行应用的标记。     

猪数量性状位点和候选基因探测研究进展及展望

通过若干数量性状位点（ＱＴＬ）和候选基因分析已探明了与猪的一些重要经济性状有关的染色体区域和基因。它们包括与生长和背膘（第３、４、５、６、７、８、１３和１４号染色体）、肉质性状（第２、３、６、７、１２、１５号染色体）、繁殖性状（第４、６、７、８号染色体）有关的染色体区域,有关窝产仔数（ＥＳＲ,ＰＲＬＲ）、抗病力（ＦＵＴＩ,ＳＬＡ,ＮＲＡＭＰ）和毛色（ＫＩＴ、ＭＳＨＲ）的候选基因被被查明,目前,一些     

猪肉色性状的QTL和候选基因的研究进展

在养猪业中,猪肉颜色是一个非常重要的肉质指标,它影响消费者的感官判断。本文综述了该性状的QTL和候选基因的研究进展。同时也分析了限制猪肉颜色QTL研究中的一些因素。     

猪抗病和免疫相关候选基因的研究进展

通过育种选择提高猪的抗病性,不仅可以为我们提供品质更优良的肉产品;还可以最大限度地减小因疫病给养猪业带来的经济损失。尤其是近年来,随着病害造成的危害和损失越来越严重,抗病育种研究成为各国育种学家倍加关注的焦点。猪的基因组计划和遗传连锁图谱的发展以及DNA分子标记密度的增加,使许多控制猪经济(数量)性状的QTL逐渐被发现,并显示出巨大的应用前景。本文概述了猪抗病性或免疫相关候选基因的研究进展,综述了动物抗病育种研究的现状、存在问题与前景。     

猪抗病和免疫相关候选基因能研究进展

通过育种选择提高猪的抗病性,不仅可以为我们提供品质更优良的肉产品;还可以最大限度地减小因疫病给养猪业带来的经济损失。尤其是近年来,随着病害造成的危害和损失越来越严重．抗病育种研究成为各国育种学家倍加关注的焦点。猪的基因组计划和遗传连锁图谱的发展以及DNA分子标记密度的增加,使许多控制猪经济（数量）性状的QTL逐渐被发现,并显示出巨大的应用前景。本文概述了猪抗病性或免疫相关候选基因的研究进展,综述了动物抗病育种研究的现状、存在问题与前景。     

猪肌内脂肪酸候选基因研究进展

本综述了影响猪肌内脂肪酸候选基因,如心脏型脂肪酸结合蛋白基因、MI基因、钙蛋白酶抑制蛋白基因、过氧化氢酶体激活增殖受体基因,存在的问题及应用前景。     

猪脂肪性状相关候选基因的研究进展

脂肪性状是肉质的一项重要指标,文中综述了影响猪脂肪性状的几个候选基因,即脂肪细胞定向和分化因子1(ADD1)基因、脂联素(AMP)基因、二酰基甘油酰基转移酶1(DGAT1)基因、脂肪酸结合蛋白(FABP)基因、脂蛋白脂酶(LPL)基因、肥胖(Ob)基因、解偶联蛋白3(UCP3)基因等的研究进展,以期为改善猪脂肪性状提供参考。     

Identification of candidate markers on bovine chromosome 14 (BTA14) under milk production trait quantitative trait loci in Holstein

The objective of this study was to identify single-nucleotide polymorphisms using a bovine chromosome 14 high-density SNP panel after accounting for the effect of DGAT1. Linkage disequilibrium information and sire heterozygosity were used to select markers for linkage analysis on bovine chromosome 14 for milk production traits in 321 Holstein animals. Results show putative milk peaks at 42 and 61 cM, both at p<0.10, a fat yield peak at 42 and 63 cM, both at p<0.05; a protein yield peak at 42 (p<0.01) and 84 cM (p<0.05); fat per cent peaks at 3 (p<0.01) and 29 cM (p<0.05), and a protein per cent peak at 4 cM (p<0.05). Once quantitative trait loci positions were established, allele substitution effects for all markers were evaluated using the same statistical model. Overlaying information between quantitative trait loci (QTL) and allele effect analysis enabled the identification (p<0.01) of 20 SNPs under the milk yield QTL, 2 under both of the fat yield peaks, 8 and 9 under the protein yield peaks, 2 and 6 for the fat per cent peaks and 5 for the protein per cent peak. One SNP in particular, ss61514555:A>C, showed association with 3 of the 5 traits: milk (p=1.59E-04), fat (p=6.88E-05) and protein yields (p=5.76E-05). Overall, combining information from linkage disequilibrium, sire heterozygosity and genetic knowledge of traits enabled the characterization of additional markers with significant associations with milk production traits.     

猪4、8和13染色体上肉质性状的QTL定位

214头猪(180头F2个体)组成的资源家系中,在猪的第4、8和13染色体上共选取23个微卫星标记,对11种肉质性状做了QTL定位,这些肉质性状包括:背最长肌肌内脂肪率(IMF)、背最长肌含水量(WM)、背最长肌系水力(WHC)、背最长肌失水率(DLR)、背最长肌pH(pH1)、股二头肌pH(pH2)、头半棘肌pH(pH3)、背最长肌肉色值(MCV1)、股二头肌色值(MCV2)、背最长肌大理石纹评分(MMS1)和股二头肌大理石纹评分(MMS2)。结果表明:检测到2个染色体极显著水平的QTL(P≤0.01),它们是定位在SSC13上55 cM处的IMF QTL,和定位在SSC4上10 cM处的WM QTL;4个染色体显著水平的QTL(P≤0.05),它们是2个MCV2 QTL(SSC8上110 cM处和SSC13上70 cM处)、1个MMS1 QTL(SSC8上185 cM处)和1个MMS2 QTL(SSC8上185 cM处)。上述QTL解释的表型变异从0.16%(SSC8上MCV2 QTL)到17.84%(SSC8上MMS2 QTL)。     

Interval mapping of growth quantitative trait loci in Japanese Black beef cattle using microsatellite DNA markers and half-sib regression analysis

A confirmatory scan for the regions of bovine chromosome 1 segregating the quantitative trait loci (QTL) influencing birthweight, weaning weight, yearling weight, and preweaning and postweaning average daily gains was performed by genotyping half‐sib progeny of four Japanese Black sires using microsatellite DNA markers. Data were analyzed by generating an F‐statistic every 1 cM on a linkage map by the regression of phenotype on the probabilities of inheriting an allele from the sire after adjusting for the fixed effects of sire, sex, parity and season of birth as well as age as a covariate. Permutation tests at chromosome‐wide significance thresholds were carried out over 10 000 iterations. A significant QTL for birthweight at 114 cM was detected in the sire 2 family. This identification of a birthweight QTL in Japanese Black cattle may be useful for the implementation of marker‐assisted selection.     

凉山半细毛羊初生重QTL的研究

选取凉山半细毛羊7个父系半同胞家系,利用绵羊1号染色体上11个微卫星标记,通过聚合酶链式反应（polymerase chain reaction,PCR）对凉山半细毛羊初生重QTL进行了研究。QTL分析的结果表明,在其中一个家系B3K5055中,1号染色体微卫星标记ILSTS004与CSSM004之间检测到影响初生重的QTL,其LOD值为3.338,位于置信区间95%（2.73）和99%（3.49）之间。     

用于鸡生长和肉质性状定位资源群体的构建

采用远交F-2设计,以杏花鸡(A系)为亲本,分别与隐性白洛克鸡(B系)、泰和丝羽乌骨鸡(C系)进行全同胞和半同胞的正反交,产生了包含A♂×B♀、B♂×A♀、A♂×C♀、C♂×A♀4个杂交组合的各两组F2群体,并进行详细的性状表型记录,建立了可用于定位生长和肉质的数量性状座位(quantitative trait loci,QTL)的4个资源群体。对F2群体的各种性状表型值进行分析,结果显示,F2群体各生长性状和肉质性状都分离得很好。资源群体有足够的群体规模,并有利于校正母体效应和环境影响,保证有效单核苷酸多态性(single nucleotide poly-morphism,SNP)检测数量和QTL定位的准确性,使资源群体的构建达到了预期的效果。     

玉米持绿相关ＱＴＬ整合图谱构建及一致性ＱＴＬ区域内候选基因发掘

 以玉米高密度遗传连锁图谱ＩＢＭ２２００８Ｎｅｉｇｈｂｏｒｓ为参考图谱,收集来自不同实验中的１７３个玉米持绿相关数量性状位点（ｑｕａｎｔｉｔａｔｉｖｅｔｒａｉｔｌｏｃｕｓ,ＱＴＬ）信息,利用ＢｉｏＭｅｒｃａｔｏｒ２．１软件,构建出玉米持绿相关ＱＴＬ 整合图谱;采用元分析技术,在１,４,５,９号染色体上发掘出５个持绿“一致性”ＱＴＬ 区间。根据“一致性”ＱＴＬ 区间两端标记在玉米物理图谱Ｂ７３ＲｅｆＧｅｎ＿ｖ２上的位置,将“一致性”ＱＴＬ 区间进行物理图谱定位,利用ＰｌａｎｔＧＤＢ（ｈｔｔｐ：／／ｗｗｗ．ｐｌａｎｔｇｄｂ．ｏｒｇ／）在线区段批量下载工具（ｄｏｗｎｌｏａｄｒｅｇｉｏｎｄａｔａ）下载“一致性”区间的１４４５个预测基因序列并进行生物信息学分析,发现预测基因主要参与具体的细胞过程,执行结合功能,催化、转移酶活性和氧化还原酶活性等分子功能。根据“一致性”ＱＴＬ 区间的基因位点名称,在ＮＣＢＩ中下载相关基因序列,与所在“一致性”ＱＴＬ 区 间所有预测基因保守结构域进行比对,在５个“一致性”持绿ＱＴＬ 区间内初步确定８个持绿相关候选基因。利用ＧＲＡＭＥＮＥ 网站（ｈｔｔｐ：／／ｗｗｗ．ｇｒａｍｅｎｅ．ｏｒｇ／）的Ｃｍａｐ功能,将水稻持绿基因狊犵狉（ｓｔａｙｇｒｅｅｎ）转定位于玉米物理图谱Ｂ７３ＲｅｆＧｅｎ＿ｖ２上,找到与其同源的玉米候选基因ＧＲＭＺＭ２Ｇ０９１８３７＿Ｔ０１,其序列与已发表的玉米衰老诱导叶绿体持绿蛋白基因狊犵狉１序列一致。     

Building phenotype networks to improve QTL detection: a comparative analysis of fatty acid and fat traits in pigs

Models in QTL mapping can be improved by considering all potential variables, i.e. we can use remaining traits other than the trait under study as potential predictors. QTL mapping is often conducted by correcting for a few fixed effects or covariates (e.g. sex, age), although many traits with potential causal relationships between them are recorded. In this work, we evaluate by simulation several procedures to identify optimum models in QTL scans: forward selection, undirected dependency graph and QTL-directed dependency graph (QDG). The latter, QDG, performed better in terms of power and false discovery rate and was applied to fatty acid (FA) composition and fat deposition traits in two pig F2 crosses from China and Spain. Compared with the typical QTL mapping, QDG approach revealed several new QTL. To the contrary, several FA QTL on chromosome 4 (e.g. Palmitic, C16:0; Stearic, C18:0) detected by typical mapping vanished after adjusting for phenotypic covariates in QDG mapping. This suggests that the QTL detected in typical mapping could be indirect. When a QTL is supported by both approaches, there is an increased confidence that the QTL have a primary effect on the corresponding trait. An example is a QTL for C16:1 on chromosome 8. In conclusion, mapping QTL based on causal phenotypic networks can increase power and help to make more biologically sound hypothesis on the genetic architecture of complex traits.     

Mapping the quantitative trait loci (QTL) for body shape and conformation measurements on BTA1 in Japanese Black cattle

The detection and mapping of segregating quantitative trait loci (QTL) that influence withers height, hip height, hip width, body length, chest width, chest depth, shoulder width, lumbar width, thurl width, pin bone width, rump length, cannon circumference, chest girth, abdominal width and abdominal girth at weaning was conducted on chromosomal regions of bovine chromosome one. The QTL analysis was performed by genotyping half‐sib progeny of five Japanese Black sires using microsatellite DNA markers. Probability coefficients of inheriting allele 1 or 2 from the sire at specific chromosomal locations were computed. The phenotypic data of progeny were regressed on these probability coefficients in a within‐common‐parent regression analysis using a linear model that included fixed effects of sex, parity and season of birth, as well as age as a covariate. F‐statistics were calculated every 1 cM on a linkage map. Permutation tests of 10 000 iterations were conducted to obtain chromosome‐wide significance thresholds. A significant QTL for chest width was detected at 91 cM in family 3. The detection of this QTL boosts the prospects of implementing marker‐assisted selection for body conformation traits in Japanese Black beef cattle.