多态性微卫星标记技术与重复序列PCR在近平滑念珠菌基因分型中的比较

目的比较多态性微卫星标记（PMM）技术与重复序列聚合酶链反应（PCR）在近平滑念珠菌基因分型中的应用。方法收集2012年3月至2013年11月间上海5家医院临床分离的近平滑念珠菌55株,经内转录间隔区序列分析（ITS）进一步鉴定菌种,共有狭义近平滑念珠菌43株,之后采用重复序列PCR和PMM技术进行基因分型,比较2种分型方法的结果和效率。结果 43株狭义近平滑念珠菌经重复序列PCR分型只有1种基因型;经PMM技术分型有22种基因型,以Ⅰ型（10株）、Ⅱ型（6株）为主,Ⅲ~Ⅶ型见于2或3株菌,其余15种基因型均只有1株菌。结论 PMM技术用于狭义近平滑念珠菌的基因分型,分辨率高、重复性好,适用于狭义近平滑念珠菌基因组微进化的监测,而重复序列PCR不适用于狭义近平滑念珠菌的基因分型。

凉山半细毛羊微卫星标记多态性的研究

利用微卫星技术对凉山半细毛羊核心育种群206个个体第1、2、3、9号染色体上的18个微卫星位点进行研究,检测微卫星在凉山半细毛羊中的等位基因数,计算等位基因频率(Pi)、遗传杂合度(H)和多态信息含量(PIC),分析了凉山半细毛羊微卫星DNA的多态性。实验采用的18个微卫星标记位点在凉山半细毛羊群体中,平均等位基因数为8.2778个(3～19个),平均多态信息含量为0.591(0.253～0.833),遗传杂合度均值为0.500(0.026～0.888)。表明该品种绵羊遗传多态性丰富,群体遗传变异较大,并且所选18个微卫星基因座适用于绵羊的遗传连锁分析研究。

Genetic Polymorphism of Ten Microsatellites in Two Goat Breeds and Its Relationship with Heterosis

[Objective] This study aimed to investigate the genetic diversity of Macheng black goat and its correlation with heterosis.[Method] Ten microsatellite markers were selected for polymorphism investigation and statistical analysis of Boer goat and Macheng black goat populations.[Result] The results showed that totally 175 alleles were found in 10 microsatellite loci; to be specific,the maximum number of detected alleles was 23,and the minimum number was 10; the effective number of alleles （Ne） was 6.4-18.1,with absolute difference value of 1.6-8.1 from the observed number of alleles.The highest gene frequency was 0.239 1 and the lowest was 0.002 7.The polymorphic information contents of all the ten microsatellite markers were above 0.95.The observed heterozygosity （Ho） ranged from 0.616 7 to 0.984 4 and the expected heterozygosity （He） ranged from 0.844 1 to 0.944 6.The average expected heterozygosity of Boer goat and Macheng black goat was respectively 0.894 0 and 0.906 7.Various body weight and body size indices of Boer goatxMacheng black goat hybrids were improved in varying degrees compared with Macheng black goat （with an increase range of 0.32％-30.06％）.The average heterosis rates of body height and chest girth were relatively high,while average heterosis rate of body weight was relatively low.[Conclusion] The genetic distance between Boer goat and Macheng black goat was 0.379 5,which is consistent with the geographical distribution of Boer goat and Macheng black goat populations and is fully relevant to the heterosis of Boer goat × Macheng black goat hybrids,indicating that investigating polymorphism via microsatellite loci is one of the feasible means to predict and analyze heterosis between varieties.

云南地区先天性髋关节脱位四个家系X染色体易感基因连锁分析

目的研究先天性髋关节脱位(CDH)与X染色体之间有无连锁关系,为进一步寻找疾病易感基因的全基因组扫描进行初步尝试。方法以4个云南地区CDH家系为研究对象,提取DNA。选用人类连锁协作中心(The Cooperative Human linkage Center,CHLC)开发的17个分布于X染色体的微卫星多态标记进行PCR扩增,产物进行非变性凝胶电泳,银染色。凝胶分析系统行等位基因分型。应用LINKAGE软件包在不同的重组率条件下行参数型连锁分析,设疾病基因频率为0.02。结果所有位点表现了较高杂合度和多态性,基因型数据符合孟德尔定律。在X染色体遗传标记DXS8091连锁分析时,发现重组率=0.0时,Lod=2.184339,提示可能存在连锁。又在DXS8091附近每隔3cm的范围内选择了7个多态性位点进行同样的实验,但两点连锁Lod<1,不支持存在两点间的连锁。提示家系CDH与各微卫星位点不存在连锁关系。结论排除云南地区CDH家系致病基因位于X染色体。

三核苷酸重复疾病与植入前遗传学诊断

三核苷酸重复疾病 (TRD)是指由于致病基因三核苷酸重复序列拷贝数目的不稳定而异常扩增导致的一类常见的遗传性疾病。它包括多种神经系统变性性疾病 ,尤其是脊髓小脑性共济失调 (SCA)。采用 PCR或 FISH技术的植入前遗传学诊断 (PGD)通过对遭受多种单基因遗传病威胁的早期胚胎的检查而从根本上避免患病后代的产生 ,具有广阔的临床应用前景。

Characterization of 12 polymorphic microsatellite markers in the Chinese tree shrew (Tupaia belangeri chinensis)

The Chinese tree shrew (Tupaia belangeri chinensis) is a small experimental animal with a close affinity to primates. This species has long been proposed to be an alternative experimental animal to primates in biomedical research. Despite decades of study, there is no pure breed for this animal, and the overall genetic diversity of wild tree shrews remains largely unknown. In order to obtain a set of genetic markers for evaluating the genetic diversity of tree shrew wild populations and tracing the lineages in inbreeding populations, we developed 12 polymorphic microsatellite markers from the genomic DNA of the tree shrew. An analysis of a wild population of 117 individuals collected from the suburb of Kunming, China, showed that these loci exhibited a highly expected heterozygosity (0.616). These 12 microsatellites were sufficient for individual identification and parentage analysis. The microsatellite markers developed in this study will be of use in evaluating genetic diversity and lineage tracing for the tree shrew.

Microsatellite DNA polymorphisms and the relation with body weight in sea cucumber Apostichopus japonicus

The relationship between microsatellite polymorphism and body weight of captive bred Chinese sea cucumber Apostichopus japonicus was investigated in two local populations in Dalian. Among ten loci discovered, nine show changes except for AJ07 loci. Seven loci were found highly polymorphic in both populations. For each locus in two populations, the average number of alleles is 6.428 6 and 6.285 7, the average observed heterozygosity at 0.225 7 and 0.245 9, the expected heterozygosity at 0.776 8 and 0.748 8, the polymorphism information content (PIC) at 0.709 2 and 0.674 6, respectively. Further analysis show significant correlation between A. japonicus body weight and occurrence markers AJ02 and AJ04. The findings of the relation may be helpful for molecular breeding, as well as the marker-assisted selection of sea cucumbers.

Development of 57 Novel Polymorphic Microsatellite Markers in Half-Smooth Tongue Sole(Cynoglossus semilaevis)

Half-smooth tongue sole (Cynoglossus semilaevis) is a promising species for aquaculture in China.The wild population of C. semilaevis is under threat from environmental factors. Microsatellite markers are very suitable for assessing genetic diversity. Four microsatellite-enriched libraries of half smooth tongue sole (Cynoglossus semilaevis) were constructed,from which 57 polymorphic microsatellites were isolated and characterized.The polymorphism of these microsatellites was assessed by genotyping in 30 individual fish.The number of alleles ranged from 2 to 11, with an average of 4.614 alleles per locus.The values of observed and expected heterozygosities ranged from 0.1000 to 1.0000 and from 0.0966 to 0.8847 respectively. Polymorphism information content (PIC) ranged from 0.0905 to 0.862.These markers would be useful for population structure assessment,genetic linkage map construction and parentage analysis for this species.

Polymorphism of microsatellite sequence within signal transduction coding genes in phytopathogenic fungus, Magnaporthe grisea

Sixteen polymorphic microsatellite markers suitable for population genetic structure analysis and signal transduction coding genes variation measurement were developed for rice blast fungus, Magnaporthe grisea. Polymorphism was evaluated by using forty-six isolates collected from diverse geographical locations （including japonica grown zone, indica grown zone） and rice varieties. Preliminary results indicated that each locus resolved multiple alleles ranging from three to fourteen. The results showed that these SSR-containing genes are also polymorphic in the nature population.

常染色体显性高度近视一家系连锁定位分析

目的通过连锁定位分析，探讨一个中国原发性高度近视家系的致病基因与已报道高度近视相关连锁位点的关系。方法选择一个连续3代发病的常染色体显性高度近视家系，选取位于18p11．31，12q21-23，7q36，17q21-23，4q22-27，2q37．1，7p15．3，15q12-13，10q21.1这9个已报道的常染色体显性高度近视致病基因连锁位点的18个多态性微卫星标记物进行srR基因分型，采用两点法进行连锁分析。结果本家系受累者皆为高度近视，屈光度从-6．00D到-20．00D不等，符合常染色体显性遗传特征。分析显示此9个遗传标记位点与该家系致病基因均不连锁，比值比均〈-1。结论该家系存在一个新的致病基因连锁位点，需进一步实施全基因组多态性微卫星标记连锁分析以确定该家系致病基因的染色体定位。

云南地区先天性髋关节脱位4个家系22号与7号染色体易感基因连锁分析

目的探讨先天性髋关节脱位(CDH)与22、7号染色体之间的连锁关系。方法以4个云南地区CDH家系为研究对象,提取所有家系成员的DNA。选用人类连锁协作中心(CHLC)开发的微卫星多态标记,其中8个平均分布于22号染色体,10个分布于7号染色体。进行PCR扩增,产物进行非变性凝胶电泳,银染色。凝胶分析系统行等位基因分型。应用Linkage软件包在不同的重组率条件下行参数型连锁分析,设疾病基因频率为0.02。结果所有位点表现了较高杂合度和多态性,基因型数据符合孟德尔定律。22、7号染色体两点连锁分析,LOD值<1,表示不存在连锁关系。提示4个家系CDH与各微卫星位点不存在连锁关系。结论排除云南地区CDH家系致病基因位于22、7号染色体上。