猪全基因组中微卫星分布规律

利用生物信息学方法搜索猪全基因组中完整型微卫星序列,并对其基因组中微卫星数量、频率以及分布规律进行了研究。搜索到猪全基因组中1⁶个碱基重复类型微卫星位点数为1 149 884个,占其全基因组长度的比率为0.85%,出现频率为1/2.22 kb。猪第1条染色体(143 330个)中微卫星数量最多,其次是第2、6和13条染色体,而较少的是第12、18条染色体和Y染色体。猪性染色体X和Y序列长度差异极显著,X染色体序列长度是Y染色体的88.10倍,其微卫星数量也存在明显差异(58 437 vs 814)。通过检验表明,猪染色体长度与其所含微卫星数量具有高度正相关性(r=0.913,P<0.01)。猪全基因组中完整型微卫星各重复类型中,单碱基重复类型数量最多,占其微卫星总数量的比率为62.95%;其次依次是二碱基、四碱基、三碱基、五碱基、六碱基重复类型。猪全基因组中微卫星重复拷贝类别数量较多的是A、AC、AT、AAC、AAT、AAAT AAAC、AAAG、AAGG,而数量较少的是C、CG、AGC、AGT、ACT、AGCG、AGTC、ACTG和CCGG。     

微卫星标记BMS2508在4个山羊品种中的遗传多样性研究

微卫星DNA又称简单序列重复、短串联重复序列和简单序列长度多态性,广泛存在于真核生物基因组中.微卫星多态性是由于减数分裂过程中不等交换造成变异而产生的,具有保守性,其核心序列为2～6 bp,重复约10～20次,属于等显性遗传.自1989年在人类基因组研究发现微卫星多态性后,目前在马、牛、猪、绵羊和鸡等动物基因组中也筛选出了大量的微卫星标记,但山羊等动物中则相对较少.     

牦牛Y染色体基因组单纯型微卫星丰度分析

微卫星或简单序列重复（SSRs）广泛分布于真核生物基因组中,其在物种基因组结构组成和功能中发挥着重要作用。本研究以2021年报道的牦牛（Bos grunniens）Y染色体基因组序列为研究对象,利用生物信息学方法系统分析了其单纯型微卫星的丰度状况。结果表明,在牦牛Y染色体基因组（26.36 Mb）中共发现12 699个1～6个碱基重复的单纯型SSRs,总长为0.33 Mb,平均长度为25.68 bp,相对频率和相对密度分别为481.77 loci/Mb和12 371.73 bp/Mb,提示牦牛Y染色体基因组包含约1.25%的单纯型SSRs。6类单纯型SSRs在牦牛Y染色体上分布不均匀,其中二碱基重复的SSRs最为丰富,总数为5 835个（45.95%）,平均长度为27.82 bp,而单碱基和三、四、五、六碱基重复的SSRs所占比例分别为29.79%、9.66%、8.81%、5.57%和0.22%。不同类别的单纯型SSRs其不同重复单元的重复次数存在差异,其中以A、AC、AAC等为重复单元的单纯型SSRs在牦牛Y染色体上所含比例相对较高;各重复单元重复次数的范围分别集中在12～20次（单...     

畜禽微卫星的应用

微卫星（Ｍｉｃｒｏｓａｔｅｌｉｔｅ）是指由１－６ｂｐ的碱基序列为核心,呈串联重复状散在分布于整个基因组的ＤＮＡ序列。由于微卫星标记在基因组中具有数量大、分布广、分布均匀、多态含量丰富及检测方便适合自动化和半自动化分析的优点,已成为各物种遗传图谱构建、...     

绵羊(ATAG)n四碱基微卫星位点的筛选及其在亲子鉴定中的应用

本试验旨在筛选绵羊高度多态性四碱基微卫星遗传标记,建立适用于绵羊亲子关系鉴定的实验体系。试验以小尾寒羊为主要研究对象,从已有的绵羊参考基因组序列出发,基于全基因组序列筛选法共筛选出53个（ATAG）_n四碱基重复微卫星位点,然后通过基因分型数据共筛选出30个扩增效果好、多态信息含量（PIC）丰富的四碱基重复微卫星位点;30个位点的基因分型结果表明,共扩增出253个等位基因,平均等位基因数为8.433,等位基因数均>5,多态信息含量在0.566~0.898,观测杂合度（Ho）范围在0.548~0.903,期望杂合度（He）范围在0.631~0.921,平均期望杂合度为0.776;哈代-温伯格平衡检验30个位点均处于遗传平衡状态。随后根据PCR的扩增效率从获得的30个多态性位点中筛选出22个微卫星位点用于亲权排除概率的计算,根据多态信息含量的大小由高到低依次增加位点数进行组合。结果表明,在两个亲本的基因型均未知的情况下,标记位点数为15个时,累积排除概率可达到99.99%,其中单个位点的第一非亲排除率（non-exclusion probability of the first parent,NE-1P）介于0.321~0.663之间。利用建立的亲子鉴定体系对16只具有系谱记录的小尾寒羊样本进行检测,结果共鉴定出4个具有高置信度的绵羊家系,鉴定结果与系谱记录完全一致。本试验为绵羊分子系谱的构建、亲子鉴定以及保障绵羊育种工作的正常开展奠定重要基础。     

微卫星标记及其在动物遗传育种中的应用

微卫星技术是20世纪80年代末期发展起来的能有效区别不同物种、不同群体及不同基因型个体的分子标记,可作为第二代分子标记。微卫星标记广泛分布于各真核生物基因组中,且随机分布。微卫星DNA(Microsatellite)是一类以1~6 bp的核苷酸为基本单位,呈串联重复状散在分布于整个基因组的重复序列,具有数量多,分布广且均匀,多态性丰富和     

微卫星DNA标记及其应用

微卫星DNA存在于大多数生物的基因组中,一般由1～6个核苷酸的串联重复片段构成,由于重复单位的重复次数在个体间呈高度变异性并且数量丰富,所以微卫星DNA标记的应用范围非常广泛。笔者就微卫星DNA标记在基因组连锁图构建、基因定位、QTL分析、标记辅助选择、杂种优势预测、亲缘关系鉴定、近交动物以及医学等方面的应用作逐一概述。     

微卫星标记在绵山羊育种中的应用研究

微卫星技术是20世纪80年代发展起来的一种能有效区别不同物种、不同群体以及不同基因型个体的分子标记，因此微卫星标记被广泛应用于各种动植物的分子领域的研究，微卫星标记在家畜遗传育种与繁殖中的研究随着人类基因组计划的进展而得到了空前的发展，当对猪、鸡和牛的物理图谱构建完成了一部分之后，国内外的学者已经开始了对绵羊和山羊的基因组的研究分析，并且取得了一些可喜的成绩。本文就微卫星标记在绵山羊育种中的应用进展做一介绍。     

牛亚科物种TRs分布特点及着丝粒区卫星DNA进化研究

旨在研究牛亚科物种间串联重复序列（tandem repeats sequence，TRs）的分布特点及着丝粒区卫星DNA的进化关系。本研究基于普通牛、瘤牛、牦牛、水牛、野牛、独龙牛6个牛亚科物种的基因组序列，研究了不同物种间TRs的组成、分布及结构特点，并分析了6个牛亚科物种染色体着丝粒区卫星DNA的进化关系。结果表明：1）TRs在牛亚科物种中平均占比为2.03%，平均长度54.93 Mb，其中普通牛的占比最高3.42%（93.00 Mb），瘤牛最低1.42%（37.88 Mb）。2）微卫星DNA在3类TRs中位点数最多，为483 405，占TRs总位点数85.64%，高于小卫星DNA（43 026，7.62%）和卫星DNA（38 180，6.75%）。3）通过对微卫星DNA丰度和平均长度分析发现，二碱基微卫星DNA在牛亚科物种中丰度最高，为70.93 loci/Mb，且以AC拷贝类别为主。4）通过构建着丝粒区1.715和1.723卫星DNA的系统发育树发现，1.715卫星DNA普遍存在于牛亚科物种的基因组中，而1.723卫星DNA在牦牛中不存在，两类卫星DNA在不同物种间或不同染色体上存在不同程度分化，具有较明显的种间特异性。TRs在牛亚科6个物种中平均占比为2.03%，微卫星DNA为TRs主要序列，且二碱基微卫星丰度最高，并以AC拷贝类别为主；1.715卫星DNA普遍存在于6个牛亚科物种的基因组中，但在物种间或染色体间存在不同程度分化。本研究结果为牛亚科物种间TRs分布特征及进化关系研究提供了重要理论依据。     

微卫星DNA标记与乌骨鸡屠宰性能的相关分析

微卫星(mierosatellite)DNA标记是由重复单位为2～6 bp的核苷酸序列所构成的串联重复序列,由于重复单位的重复数目不同,形成了微卫星标记的丰富多态性.微卫星标记普遍存在于真核生物基因组中,由于具有数量多、分布广、多态性丰富、呈共显性遗传方式及检测快速和方便等优点而成为当今包括人类在内的各物种基因作图的首选标记,并在基因诊断、物种的演变追踪、QTL分析、系谱的确定、群体遗传结构分析、标记辅助选择等方面显示出巨大的应用价值.     

Distribution Difference of Microsatellite in 7 Domestic Animals Genomes

To investigate whether difference in SSRs distribution of 7 domestic animals genomes, the microsatellite sequence were searched by using MSDB (Microsatellite Search and Building Database) and analyzed in pig, horse, cow, goat, sheep, chicken and dog genomes.Preliminary results showed that SRRs number, frequency and density were found to be largely variable among these animals.The most abundant distribution was observed in dog genome with 1 436 242 identified SSRs loci.The minimum SSRs (276 564) number was found in chicken genome.Yet, the minimum SSRs (430 760) frequency and density were found in horse genome.Among these SSRs, mononucleotide repeat type motif was the most abundant and pentanucleotide repeat type motif was the rarest in all animals.Meanwhile, all the dominant SSRs for different repeat types were abundant in nucleotide A and T.In addition, there was variability among 7 animals of SSRs distribution.In general, SSRs distribution was the most similar in cow, goat and sheep genomes, and chicken was the most different from other animals.The results also showed that the length of microsatellite ranged mainly from 12 to 20 bp in all animals, which might be due to selection pressure of convergence.In short, these results revealed difference as well as conservation in SSRs distribution among different domestic animals genomes.In particular, genetically close animals tended to have similar SSR distribution patters.This would provide a basis for subsequent research of SSRs function.     

Reactivity of eleven anti-human leucocyte monoclonal antibodies with lymphocytes from several domestic animals

Nine commercially available monoclonal antibodies and two monoclonal antibodies from The American Type Culture Collection, raised against various human leucocyte surface antigens, were tested on lymphocytes from cow, sheep, goat, swine, horse, cat, dog, mink, and rabbit as well as man. Four antibodies bound to lymphocytes from some of the animals. These were the antibodies against CD8 and CD4 antigen, the antibody to C3b-receptor, and the antibody to the HLA-DR antigen. The CD8 antigen-reactive antibody reacted with lymphocytes from mink, cat, dog, and sheep, while the CD4 antigen-reactive antibody reacted with lymphocytes from mink. The anti-C3b-R antibody reacted with lymphocytes from horse, swine, dog, and cat, and the anti-HLA-DR reacted with lymphocytes from cow, goat, sheep, horse, dog, cat, and mink.     

上海地区多种动物莱姆病的血清学调查

为探讨猪、牛、羊、马、犬、鸡、鸭和野鸟等与人类关系密切的多种动物莱姆病的血清流行病学状况,从上海地区采集血清870份,应用酶联荧光测定技术(ELFA)检测莱姆病抗体。猪、牛、羊、鸡、鸭和野鸟中均未检测到莱姆病抗体,马血清中莱姆病抗体阳性率为18.5%,犬血清中莱姆病抗体阳性率为12.3%。结果表明,上海地区动物群中莱姆病的感染率相对较低,马和犬在莱姆病传播中的重要性应引起重视。     

家养动物线粒体DNA最新研究进展

线粒体DNA多态性研究对于了解家养动物的驯化历史十分重要.本文对家猪、黄牛、水牛、马、驴、绵羊、山羊与家鸡的线粒体DNA多态性最新研究进展作了总结.通过mtDNA D-loop研究,发现家养动物都是通过野生动物多次驯化而来,可能有多个驯化地点,表现出复杂的驯化历史.     

羊肉产品中若干动物源性成分的七重PCR检测技术应用研究

试验建立了猪、牛、绵羊、山羊、鸡、马和牦牛种属鉴别的七重PCR体系,分析了牛、牦牛、山羊源性成分七重PCR检测的灵敏度,检测了10种市售羊肉产品中的动物源性成分。结果表明,采用常规的琼脂糖凝胶电泳可以区分157～517 bp的片段及相互差异在41 bp以上的多重PCR扩增产物,从而实现对这7个物种的快速及准确鉴别,其中对3个物种(牛、牦牛、山羊)DNA的检测灵敏度在2.5 ng左右;所检测的10种羊肉产品中有2种并不是包装上所宣称的羊肉,而是混杂有牛肉或完全用牛肉替代。     

Isolation and culture of preantral follicles for retrieving oocytes for the embryo production: present status in domestic animals

The development of efficient ovarian preantral follicle (PF) isolation and culture systems provide a large number of oocytes for the manipulation and embryo production. It also helps for understanding the mechanisms of follicle and oocyte development. Isolation and culture protocols for PFs were developed for many domestic species like cattle, buffalo, sheep, goat, pig, horse, camel, dog and cats; however, embryo production from oocytes derived from in vitro grown PFs was reported only in pigs, buffalo, sheep and goat. The rate of oocyte maturation from PFs grown in vitro is low and requires considerable research. This paper presents an overview of isolation and culture systems of PFs that have been developed for domestic species (cattle, buffalo, sheep, goat, pigs, horse, camel, dog and cat) along with the current status of progress achieved in the direction of producing embryos using PFs as the source of oocyte in these species.     

胶乳凝集抑制试验快速鉴定肉种类研究

以羧化聚苯乙烯胶乳作载体,将动物血清分别共价交联到载体微球表面,制成免疫微球。将此微球同相应抗血清配对,进行胶乳凝集抑制试验以鉴定牛肉、马肉、羊肉、狗肉和猪肉。通过对162份牛肉、43份马肉、100份猪肉、34份羊肉、30份狗肉、10份骡肉、4份驴肉和7份山羊肉的鉴定,制备的5种胶乳试剂敏感性均为100％。除马肉胶乳试剂和羊肉胶乳试剂有种属内交叉反应外,其它胶乳试剂特异性为100％。实验具有良好的重复性,试剂稳定性强,易于保存。5分钟内出结果,操作简便,适于基层单位应用。     

山羊痘病毒反向末端重复序列的克隆与序列分析

应用PCR方法扩增山羊痘病毒QL、LD、Y、B-株反向末端重复序列片段,将其克隆至pMD18-T载体,构建了重组质粒pMD18-ITR,再将该重组质粒转化DH5α感受态细胞进行培养,对通过PCR、酶切鉴定为阳性的重组菌进行序列测定,并将所得序列与GenBank收录的2株山羊痘病毒、3株绵羊痘病毒全基因序列进行比较分析。结果:所测4个毒株序列与GenBank上收录的山羊痘病毒该片段核苷酸序列的同源性均为100%,与绵羊痘病毒该片段核苷酸序列的同源性均为98.3%。研究结果表明,山羊痘病毒反向末端重复序列与已收录的羊痘毒株之间该片段的同源性非常高,为今后兽医临床上应用PCR方法检测羊痘病毒提供了另一更为特异、保守的基因片段。     

Purification and sensitivity of Clostridium chauvoei hemolysin to various erythrocytes

Using ammonium sulphate fractionation, the Clostridium chauvoei hemolysin was purified by cation exchange chromatography and sephacryl S-100 gel filtration. The molecular mass of the hemolysin, determined by SDS-PAGE was found to be approximately 27kDa. The activity of the hemolysin was determined in erythrocytes of various animals, with sensitivities observed in the order of cow, sheep, chicken, rabbit, rat, mouse, dog and horse. Temperature affected the sensitivity of erythrocytes to C. chauvoei hemolysin. These results may reflect distinct characteristics of the hemolytic activity of C. chauvoei hemolysin and that the hemolysin may be pore-forming.     

DNases in milk and blood sera from different species.

DNases were demonstrated in samples of colostrum and blood serum from man and various domestic animals. The measurable DNase activity recorded was highest in samples from cat and dog and lowest in samples from goat, horse, pig and sheep. In contrast to DNases produced by certain bacteria, these enzymes were thermo-labile and the activity was maximal in the area pH 5.0–5.5.A modification of an agar medium originally described for the demonstration of bacterial DNases was found to be suitable for assays of DNases from colostrum, milk and serum.