猪1号染色体微卫星多态性研究及遗传连锁图谱的构建

微卫星具有多态性高、保守性好等优点。本研究选取以20cM左右的间距均匀分布于1号染色体的8个多态微卫星基因座构建猪1号染色体的遗传连锁图谱,为进一步进行重要经济性状基因座的定位打下基础。试验结果表明,8个基因座等位基因数目2~5个,各个基因座等位基因频率在0.015~0.75之间,杂合度为0.39705~0.67675,多态信息含量为0.32925~0.59316。构建的资源家系遗传连锁图谱总长181.5cM,与USDA结果基本一致,可进一步用于猪数量性状基因座定位的研究。 The Microsatellite Polymorphism Research on Porcine Chromosome 1 and the Construction of Its Genetic Map QU Yan-chun,DENG Chang-yan,XIONG Yuan-zhu,SU Yu-hong,ZHENG Rong,LIU Gui-lan The Key Laboratory of Pig Breeding and Genetics,The Ministry of Agriculture, Huazhong Agricultural University,Wuhan 430070,China Abstract:As a molecular marker,microsatellite has many advantages such as high polymorphism and good conservativeness in animal genetic research.The study chose 8 microsatellite markers that evenly distributed on chromosome 1 with a distance about 20 cM to build the genetic map of porcine chromosome 1.The results of our experiment are as follows:the number of alleles for 8 markers is 2 to 5,their gene frequency is from 0.015 to 0.75,the heterozygosity is from 0.39705 to 0.67675 and the polymorphic information content is from 0.32925 to 0.59316.The map we built is basically in consistent with the result of USDA and can be used in searching quantitative traits loci in pigs. Key words：porcine; microsatellite; heterozygosity; polymorphic information content; genetic map     

中国人群红细胞血型座位的杂合度

分析了我国十二个民族的红细胞血型座位上的杂合度，发现不同民族各座位的平均杂合度不同，北方民族比南方民族的高，而且以维吾尔族的最高，壮族与高山族的最低。不同座位以杂合度大小排列，ABO、ABH、Kidd、MN、Xg、Lewis、Rh(Cc)、Rh(Ee)、P、Rh(Dd)、Duffy、S、Diego、Lutberan、Kell。此外，汉族的平均杂合度略低于白种人，而与黑种人相近。     

一般家系二分类性状的贝叶斯连锁分析方法

应用阈值模型和可逆的跳跃马尔可夫链方法提出一种适用于人类一般家系中复杂二分类性状基因定位的连锁分析方法,此方法可以同时估计易感基因位点的数目与位置。     

SSR座位与秦川牛及其杂种牛生长性状的相关性分析

本研究以秦川牛及其与利木赞牛、德国黄牛以及红安格斯牛的杂交F_1代(4月龄)共4个牛群体总计164个个体为研究对象,以体尺性状作为衡量牛生长发育性状的指标,运用最小二乘线性模型,分析了10个SSR座位与生长发育性状的相关性.结果表明,10个多态SSR座位基因型对秦川牛及其杂交后代的生长发育性状效果不一:在ETH225座位,CH基因型(152/172)在4个群体内的体高、十字部高、尻长均显著低于其它基因型;BM1500座位,BC基因型(150/164)在十字部高、胸围、体重指标上高于BD型(150/170);HEL5座位,BD基因型(160/170)、EH基因型(172/180)在多项指标上大于其他基因型;BM2113座位,CG基因型(144/164)在体高、体长、腰角宽、胸围和体重指标上大于CF(144/160)、BF(142/160)基因型;CSSM66座位,BG基因型(183/211)在体高、十字部高、胸围指标高于AE基因型(181/207);HEL9座位BG基因型(158/178)在体高,十字部高、胸围、尻长和体重指标上大于EJ基因型(166/186).本研究的结果旨在为科学评价秦川牛的遗传资源价值和良种选育提供理论依据.     

连锁分析研究的Meta分析方法

目前,随着基因定位研究的普遍开展,由于复杂性状每个易感基因的弱效应及单个研究中家系资料的不足造成各研究间的结果常不一致。如何科学地分析这些众多的不一致的结果正是目前基因定位和克隆研究者普遍面临的一个问题。为此,针对不同的连锁分析研究设计,以实例阐述了有关的方法及技巧。     

连续近交下家猪微卫生基因组杂合度与经济性状的相关性研究

从已这位于家猪０１、０２、１１、１３、１７、１８号染色体上的遗传标记中选用５６个具有足够覆盖率的微卫生标记,对１个连续５个代近交家系共１９２个头家猪进行了基因组扫描.平均微卫生标记杂合度估计基因组杂合度（ＧＨ）。ＧＨ对于屠宰重（ＳＷＴ）和日均屠宰重（ＡＤＳＧ）为显著正相关效应,对于背膘厚（ＢＦＤＰ）的相关效应不显著且方向也不一致。ＧＨ的相关效应随近交世代递增而呈非线性变化趋势;ＧＨ对于ＳＷＴ和ＡＤＳＧ的相关效应在近交前２世代呈上升趋势。２代分别到达最大值（２２．４３kg和０．１３２kg/d）,此后随近交世代的递增而递减;ＧＨ对于ＢＦＤＰ的相关效应随世代递增而非线性递减。微卫星杂合度的相关效应在不同染色体间存在较大差异,对ＳＷＴ和ＡＳＤＧ均表现为正效应,其中又以１３号染色体标记杂合度的相关效应为最大（６．３０kg和０．０３２kg／d)其次依镒为１号、１７号、１８号、２号和１１号。各染色体微卫星标记杂合度对于ＢＦＤＰ的相关效应估值的标准误差大,且效应方向不一致（１８号染色体来正效应,其余染色体为负效应）,由引得到如下３点启示,第一,对于经济性状重要的基因（e.g.QTL)不同是均衡分布于各杂染色体上,此差异可能反应出生物性状决定在染色体以及分子分上上的差异;第二,由于基因,基因互作和且背景效应的复杂性,基因（组）杂合度与性能间不为简单的相关,学可能由于标记数目不够或是标记选择不适当而误导;第三,由于高度近交（如连续同胞交配）下较高的连锁不平衡所致,有害基因可能以较高的概率民中性标记连锁遗传,由此可能部分或全部抵消杂合优势的表现,甚至出现杂合劣势。     

7个微卫星座位与北京荷斯坦母牛体细胞评分关系的研究

选择与体细胞评分紧密连锁的7个微卫星座位BM1818、BM1258、BM1443、BM1905、BM302、BM4505和CYP21,用非变性聚丙烯酰胺凝胶电泳分析其在240头北京荷斯坦母牛中的遗传变异。计算了7个微卫星座位的等位基因频率、杂合度、多态信息含量和有效等位基因数,并利用最小二乘法拟合线性模型初步探索了这7个微卫星座位与北京荷斯坦母牛体细胞评分的关系。结果表明：微卫星BM1818座位284bp／284bp、BM1258座位106bp／92bp、BM1443座位166bp／160bp、BM1905座位187bp／187bp、BM302座位142bp／140bp、BM4505座位240bp／236bp和CYP21座位215bp／198bp所对应的体细胞评分最小二乘均值较低,对乳房炎抗性而言它们是各自座位上的最有利基因型;微卫星BM1818座位286bp／286bp、BM1258座位102bp／102bp、BM1443座位170bp／160bp、BM1905座位197bp／195bp、BM302座位154bp／145bp、BM4505座位240bp／238bp和CYP21座位204bp／192bp所对应的体细胞评分最小二乘均值较高,对乳房炎抗性而言它们是各自座位上的最不利基因型。     

利用SSR标记对西瓜果肉硬度性状的连锁分析

果肉硬度作为西瓜的重要品质属性,越来越受到生产者和消费者的重视。本研究以野生种西瓜PI271769为供体亲本,栽培种西瓜203Z为轮回亲本进行高代回交,在BC7F1世代发现了果肉硬度变硬的材料。用平均分布于西瓜11条染色体的185对SSR标记对PI271769、203Z和构建的软肉池、硬肉池进行筛选,发现位于第6染色体上的标记BVWS00954具有多态性。通过单向方差分析在BC7F2分离群体的验证,表明BVWS00954与控制西瓜果肉硬度的基因连锁,且BVWS00954标记分析基因型与不同的西瓜资源果肉硬度表现型完全吻合。研究结果为控制西瓜果肉硬度基因的精细定位、图位克隆及分子标记辅助选择育种奠定了基础。     

贵州白香猪两品系微卫星座位的遗传分析

采用24个微卫星标记对贵州白香猪2个品系的遗传变异进行了检测.试验结果表明,2个品系在24个微卫星基因座的平均等位基因、平均期望杂合度、平均多态信息含量和平均近交系数分别为2.1667、2.0417,0.4074、0.4188,0.3436、0.3249和0.5377、0.5605.结果 提示贵州白香猪具有一定的遗传稳定性,已成为一个稳定的遗传群体,符合封闭群动物的遗传特征.     

大麦转基因座位结构的研究

利用质粒营救法获得基因枪法转化的4种转绿色荧光蛋白基因(green fluorescent protein,GFP)大麦的转基因座位序列,序列分析显示4种材料的转基因座位中均有完整栽体的串联重复现象,表明转基因整合是同源重组的结果.同时转基因座位中也存在不完整载体片段、基因组片段的混杂排列,说明转基因整合时也发生异常重组.微粒轰击的转基因整合是由异常重组和同源重组共同完成的.     

WHBE兔血液蛋白的特性

目的比较大耳白黑眼兔（WHBE兔）与日本大耳白兔（JW兔）和新西澜兔（NZW兔）血液蛋白的多态性,从分子水平了解WHBE兔特殊性状的遗传背景。方法采用聚丙烯酰胺凝胶电泳对WHBE兔、JW兔和NZW兔血液中的前白蛋白（Pr）,后白蛋白（Po）,前转铁蛋白1（Prt1）,前转铁蛋白2（Prt2）,转铁蛋白1（Tf1）,转铁蛋白2（Tf2）,后转铁蛋白（Ptf）,慢α球蛋白（Sag）、血红蛋白（Hbα、Hbβ）和白蛋白（Alb）共11个蛋白位点进行检测。结果Pr、Ptf、Hbα、Hbβ、Alb、Po、Sag和Prt2在所有实验兔个体中的表型一致,而Tf1、Tf2和Prt1的表型在各实验兔品系间存在显著差异。在Tf1位点,NZW兔以BC表型为主,无AA型;JW兔只有AA型,而WHBE兔以AB型为主。在Tf2位点,NZW兔有AA型,而JW兔和WHBE兔无AA型。在Prt1位点,NZW兔无AB、BB和BC表型而有AC表型。NZW兔蛋白位点的平均杂合度大于JW兔和WHBE兔。JW兔与WHBE兔的遗传距离最近。结论Tf1、Tf2和Prt1可作为区分NZW兔、JW兔和WHBE兔的特征标记,并且与WHBE兔特殊性状形成有关。JW兔与WHBE兔的亲缘关系最近。     

Shrinkage Estimation Method for Mapping Multiple Quantitative Trait Loci

In this article, shrinkage estimation method for multiple-marker analysis and for mapping multiple quantitative trait loci (QTL) was reviewed. For multiple-marker analysis, Xu (Genetics, 2003, 163:789-801) developed a Bayesian shrinkage estimation (BSE) method. The key to the success of this method is to allow each marker effect have its own variance parameter, which in turn has its own prior distribution so that the variance can be estimated from the data. Under this hierarchical model, a large number of markers can be handled although most of them may have negligible effects. Under epistatic genetic model, however, the running time is very long. To overcome this problem, a novel method of incorporating the idea described above into maximum likelihood, known as penalized likelihood method, was proposed. A simulated study showed that this method can handle a model with multiple effects, which are ten times larger than the sample size. For multiple QTL analysis, two modified versions for the BSE method were introduced: one is the fixed-interval method and another is the variable-interval method. The former deals with markers with intermediate density, and the latter can handle markers with extremely high density as well as model with epistatic effects. For the detection of epistatic effects, penalized likelihood method and the variable-interval approach of the BSE method are available.     

多QTL定位的压缩估计方法

本文综述了多标记分析和多QTL定位的压缩估计方法。对于前者,Xu（Genetics,2003,163：789—801）首先提出了Bayesian压缩估计方法。其关键在于让每个效应有一个特定的方差参数,而该方差又服从一定的先验分布,以致能从资料中估计之。由此,能够同时估计大量分子标记基因座的遗传效应,即使大多数标记的效应是可忽略的。然而,对于上位性遗传模型,其运算时间还是过长。为此,笔者将上述思想嵌入极大似然法,提出了惩罚最大似然方法。模拟研究显示：该方法能处理变量个数大于样本容量10倍左右的线性遗传模型。对于后者,本文详细介绍了基于固定区间和可变区间的Bayesian压缩估计方法。固定区间方法可处理中等密度的分子标记资料;可变区间方法则可分析高密度分子标记资料,甚至是上位性遗传模型。对于上位性检测,已介绍的惩罚最大似然方法和可变区间Bayesian压缩估计方法可供利用。应当指出,压缩估计方法在今后的eQTL和QTN定位以及基因互作网络分析等研究中也是有应用价值的。     

A Likelihood-Based Trait-Model-Free Approach for Linkage Detection of Binary Trait

Summary .  Trait-model-free (or "allele-sharing") approach to linkage analysis is a popular tool in genetic mapping of complex traits, because of the absence of explicit assumptions about the underlying mode of inheritance of the trait. The likelihood framework introduced by Kong and Cox (1997,  American Journal of Human Genetics   61, 1179–1188) allows calculation of accurate p-values and LOD scores to test for linkage between a genomic region and a trait. Their method relies on the specification of a model for the trait-dependent segregation of marker alleles at a genomic region linked to the trait. Here we propose a new such model that is motivated by the desire to extract as much information as possible from extended pedigrees containing data from individuals related over several generations. However, our model is also applicable to smaller pedigrees, and has some attractive features compared with existing models ( Kong and Cox, 1997 ), including the fact that it incorporates information on both affected and unaffected individuals. We illustrate the proposed model on simulated and real data, and compare its performance with the existing approach ( Kong and Cox, 1997 ). The proposed approach is implemented in the program lm_ibdtests within the framework of MORGAN 2.8 ( http://www.stat.washington.edu/thompson/Genepi/MORGAN/Morgan.shtml ).     

哺乳动物乳蛋白基因的表达与调控

本文在介绍了乳蛋白基因组结构及进化关系的基础上,就其乳蛋白基因表达的影响因素：顺式调控成分,反式作用因子及激素对表达的诱导进行了讨论,最后就该系统作为生物反应器的开发前景作了展望。     

浙江省不同地区实验兔血液蛋白多态性研究

目的研究浙江省不同产地实验兔血液蛋白的多态性,了解各地实验兔的遗传背景,指导优良品系的选育。方法选择兰溪、农科院、上虞和余姚等地生产的实验兔的11个血液蛋白位点进行聚丙烯酰胺凝胶电泳,根据电泳图谱分析基因频率、Hardy-weinberg平衡状态、遗传变异程度和遗传相似性。结果 Pr、Ptf、Hbα、Hbβ和Alb在所有实验兔中表现为单态,其余蛋白位点呈多态。各蛋白位点的变异程度Prt1SagTf1PoTf2Prt2。各地实验兔蛋白位点平均杂合度为兰溪农科院上虞余姚。农科院与余姚实验兔间的遗传距离最近,上虞与兰溪实验兔的亲缘关系最远,遗传相似系数分别为0.7938和0.7687。结论血液蛋白多态性反映了浙江省不同地区生产的实验兔的遗传背景,为实验兔的选育提供了实验依据。     

The Prior Distribution of the Minimum and Maximum Distance between Several Marker Loci and Quantitative Trait Loci

In order to control linkage experiments, exact formulas and approximations are derived for the minimum distance between quantitative trait loci and the nearest marker locus. The locations of the loci are assumed to be uniformly distributed over the genome. The locations of the marker loci may be known or unknown. The number and length of the chromosomes are arbitrary and therefore the results are applicable for all kinds of species. Analogous formulas are derived for the maximum distance between the quantitative trait loci and the nearest marker loci. For the probability of linkage more simple expressions are derived. The accuracy of the approximations is checked by a simulation.     

Mapping and Analysis of Dairy Cattle Quantitative Trait Loci by Maximum Likelihood Methodology Using Milk Protein Genes as Genetic Markers

Maximum likelihood methodology was used to estimate effects of both a marker gene and a linked quantitative trait locus (QTL) on quantitative traits in a segregating population. Two alleles were assumed for the QTL. In addition to the effects of genotypes at both loci on the mean of the quantitative trait, recombination frequency between the loci, frequency of the QTL alleles and the residual standard deviation were also estimated. Thus six parameters were estimated in addition to the marker genotype means. The statistical model was tested on simulated data, and used to estimate direct and linked effects of the milk protein genes, β-lactoglobulin, κcasein, and β-casein, on milk, fat, and protein production and fat and protein percent in the Dutch dairy cattle population. β-Lactoglobulin had significant direct effects on milk yield and fat percent. κ-Casein had significant direct effects on milk yield, protein percent and fat yield. β-Casein had significant direct effects on milk yield, fat and protein percent and fat and protein yield. Linked QTL with significant effects on fat percent were found for κ-casein and β-casein. Since the β-casein and κ-casein genes are closely linked, it is likely that the same QTL was detected for those two markers. Further, a QTL with a significant effect on fat yield was found to be linked to κ-casein and a QTL with a significant effect on protein yield was linked to β-lactoglobulin.     

猪肌肉蛋白质含量的QTL分析

用酶山猪与大白猪构建的资源家系检测影响肌肉蛋白质含量的数量性状座位（QTL）。测定135头F2代个体及其相应父母和祖父母在分布1号、2号和6号染色体上的24个微卫星基因型。用这些微卫星标记计算每个F2代个体固定位置的加快和显性系数,以1cM的间距肌肉蛋白质含量与这些系数进行回归分析,发现3个与肌肉蛋白质含量具有显著效应的QTL（P＜0．05）,它们分别于位于1号染色体的Sw1332和Sw2130之间,2号染色体的Sw2516和Sw1201之间,6号染色体的Sw2516和Sw1201之间,分别解释0．91％、12．76％和4．60％的肌肉蛋白质含量变异方差。结果提示,影肌肉蛋白质含量的QTL分布在多条染色体上。     

21例奶蛋白过敏患儿临床特征分析及诊治方法

目的：探讨奶蛋白过敏患儿的临床特点及诊治方法。方法：收集2012年2月-2013年2月我院接诊的21例奶蛋白过敏患儿的临床资料,将临床表现、特异性皮肤点刺试验、回避试验等结果进行总结分析。结果：患儿皮肤粘膜、消化道等症状出现时间较早,湿疹症状出现最多（71．43％）,仅有1例患儿出现发育迟缓（4．76％）;皮肤点刺试验奶蛋白阳性者12例（57．14％）,回避试验阳性率为100．00％;经过改善饮食及对症治疗,21例患儿皮肤粘膜、消化道、呼吸道系统等症状一般在4周内消失,发育迟缓在正规治疗2．4周开始缓解,8周内消失。结论：奶蛋白过敏缺乏特异症状表现,临床在出现症状后加强实验室检查。结合详细病史进行确诊,才能减少误诊的发生,及时治疗,保证患儿的正常生长发育。