利用12对微卫星分子标记对大菱鲆Scophthalmus maximus 4个引进地理群体进行遗传多样性分析。结果表明,等位基因数（A）为2~10个,平均等位基因数为4.3,有效等位基因数（Ne）为1.6~6.1,平均有效等位基因数为2.7,各位点的杂合度观测值（H...利用12对微卫星分子标记对大菱鲆Scophthalmus maximus 4个引进地理群体进行遗传多样性分析。结果表明,等位基因数（A）为2~10个,平均等位基因数为4.3,有效等位基因数（Ne）为1.6~6.1,平均有效等位基因数为2.7,各位点的杂合度观测值（Ho）为0.0000~0.5625,杂合度期望值（He）为0.3823~0.8416。各群体之间无偏倚杂合度期望值由小到大依次为丹麦群体、英国群体、法国群体、挪威群体,运用SPSS软件对无偏倚杂合度期望值进行Kruskal-Wallis检验,其结果（H=4.438,df=3,P=0.218）表明,4个群体的遗传多样性差异不显著。群体间平均遗传分化指数（Fst）为0.1117,各群体之间存在中度遗传分化。用UPGMA法进行聚类分析,4个群体聚为两类,挪威群体和丹麦群体聚为一类,法国群体和英国群体聚为一类。结合Hardy-Weinberg平衡和遗传偏离指数（d）,4个群体都不同程度的偏离平衡。4个群体具有一定的遗传分化、较好的遗传多样性,适合作为大规模家系选育的基础群体。展开更多
Chimerism is defined as the presence in a subject of more than one stable and genetically distinct cell line;cases reported so far include both patients with ambiguous genitalia and healthy subjects. The biological me...Chimerism is defined as the presence in a subject of more than one stable and genetically distinct cell line;cases reported so far include both patients with ambiguous genitalia and healthy subjects. The biological mechanisms, which may give origin to chimeras, are complex, and can be understood by analyzing DNA samples of the patients and their parents using molecular techniques. The objective of this study is to identify the mechanism of origin for the 2 cases we report. The first patient is a phenotipically normal girl with normal (external and internal) genitalia;the second patient had ambiguous genitalia and underwent surgery. DNA was purified from blood samples and, limited to Patient 1, from a sample of biliary cyst. Short tandem repeat polymorphisms were analyzed in order to identify the relative parental contribution to the patients. Molecular analyses carried out on the first patient are not fully informative because of two possible explanations (i.e. parthenogenetic and andrognetic chimera), while in the second case the presence of four alleles at some markers allowed us to identify a tetragametic chimera originnated from the fusion of two distinct embryos. Studies carried on one single tissue may not always be conclusive as they do not allow the precise identification of the mechanism of origin. In these cases, studies on more tissues are strongly suggested.展开更多
文摘利用12对微卫星分子标记对大菱鲆Scophthalmus maximus 4个引进地理群体进行遗传多样性分析。结果表明,等位基因数（A）为2~10个,平均等位基因数为4.3,有效等位基因数（Ne）为1.6~6.1,平均有效等位基因数为2.7,各位点的杂合度观测值（Ho）为0.0000~0.5625,杂合度期望值（He）为0.3823~0.8416。各群体之间无偏倚杂合度期望值由小到大依次为丹麦群体、英国群体、法国群体、挪威群体,运用SPSS软件对无偏倚杂合度期望值进行Kruskal-Wallis检验,其结果（H=4.438,df=3,P=0.218）表明,4个群体的遗传多样性差异不显著。群体间平均遗传分化指数（Fst）为0.1117,各群体之间存在中度遗传分化。用UPGMA法进行聚类分析,4个群体聚为两类,挪威群体和丹麦群体聚为一类,法国群体和英国群体聚为一类。结合Hardy-Weinberg平衡和遗传偏离指数（d）,4个群体都不同程度的偏离平衡。4个群体具有一定的遗传分化、较好的遗传多样性,适合作为大规模家系选育的基础群体。
文摘Chimerism is defined as the presence in a subject of more than one stable and genetically distinct cell line;cases reported so far include both patients with ambiguous genitalia and healthy subjects. The biological mechanisms, which may give origin to chimeras, are complex, and can be understood by analyzing DNA samples of the patients and their parents using molecular techniques. The objective of this study is to identify the mechanism of origin for the 2 cases we report. The first patient is a phenotipically normal girl with normal (external and internal) genitalia;the second patient had ambiguous genitalia and underwent surgery. DNA was purified from blood samples and, limited to Patient 1, from a sample of biliary cyst. Short tandem repeat polymorphisms were analyzed in order to identify the relative parental contribution to the patients. Molecular analyses carried out on the first patient are not fully informative because of two possible explanations (i.e. parthenogenetic and andrognetic chimera), while in the second case the presence of four alleles at some markers allowed us to identify a tetragametic chimera originnated from the fusion of two distinct embryos. Studies carried on one single tissue may not always be conclusive as they do not allow the precise identification of the mechanism of origin. In these cases, studies on more tissues are strongly suggested.
