鲍分子遗传学研究进展

阐述了近年来鲍分子遗传学方面的研究进展,总结了核型分析、等位酶、微卫星和小卫星、随机扩增多态性DNA、限制性片断长度多态性、线粒体DNA、表达序列标签研究和基因序列等技术在鲍种群遗传多样性、遗传分化、遗传结构及种质鉴定等方面的应用。并指出今后应加强鲍蛋白质组学、功能基因组学、遗传连锁图谱、数量性状基因座和标记辅助选择等方面研究。     

鳙小卫星DNA的克隆

鳙基因组ＤＮＡ 经内切酶Ｓａｕ３ＡⅠ完全酶切后，与Ｂａｍ ＨⅠ－ ｐＵＣ１８ 质粒连接，转化ＤＨ５α后，获得９３３ 个重组体。用人源小卫星探针３３ ．１５ 对重组体进行原位杂交筛选，获得１４ 个阳性克隆，取其中的１ 个阳性克隆（ 即小卫星ｐＢＣ１７４） 作探针，与５ 尾鳙和４ 尾鲢基因组ＤＮＡ 杂交，能产生具有高度变异性的、个体特异性的ＤＮＡ 指纹图，表明克隆的鳙小卫星ｐＢＣ１７４ 可用于鱼类ＤＮＡ 指纹分析。     

用DNA指纹技术研究Zmu-1:DHP豚鼠的群体遗传结构

为了鉴定Zm u-1∶DHP新品系豚鼠的遗传组成,试验以Jeffreys 33.6和33.15探针,分别与Zm u-1∶DHP和DHP 2个品系豚鼠基因组DNA的H in fⅠ和H aeⅢ酶切限制性片段进行Sou thern杂交,绘制豚鼠DNA指纹图,分析豚鼠基因组DNA限制性片段长度的多态性。结果显示,33.6探针与H in fⅠ酶组合应用,多态性程度较高,制图效果好;Zm u-1∶DHP豚鼠的DNA指纹图中,在6 kb和9 kb标记点出现特征性基因序列片段;Zm u-1∶DHP品系内的相似系数Fm=0.834±0.066,显著高于DHP品系内的Fm=0.653±0.158,也高于2个品系的Fm=0.670±0.115;Zm u-1∶DHP豚鼠2随机个体间遗传组成完全相同的机率Fmn=1.07×10-2,高于DHP豚鼠的Fmn=8.474×10-5。表明该方法用于豚鼠遗传质量检测和品系鉴定是可行的。Zm u-1∶DHP和DHP豚鼠都属远交系动物,但前者的遗传基因纯合性显著高于后者,结合性状可以看出,Zm u-1∶DHP豚鼠遗传分化形成了新的品系。     

鳙小卫星pBC174的序列结构特性分析

用双脱氧DNA测序法对鳙 (Aristichthysnobilis)小卫星 pBC174进行序列测定。其长度为 1873bp。在这段序列中 ,A T含量高达 6 4 % ,从 15 11碱基处开始 ,含有多聚腺嘌呤 多聚胞嘧啶 ,即 (AC) 13 的短重复序列的隐蔽微卫星。序列中含有 2 0种限制性内切酶的 5 7个酶切位点 ,97个不同的正向重复序列 ,其中 71个 8bp、10个 9bp、10个 10bp、2个 11bp和 4个 17bp。根据序列分析 ,认为小卫星 pBC174是由富含A的重复序列TAAAGAAA和富含T的重复序列TTTTTACA等 2个不同的核心序列组成。     

甜瓜DAMD反应体系优化及指纹图谱分析

以甜瓜DNA为模板,以小卫星DNA YNZ22核心序列为引物,在甜瓜上建立了DAMD的优化反应体系,并用该优化体系分析了28份甜瓜的遗传多样性,开发了一种揭示甜瓜种质间遗传差异的新型分子标记.     

DNA fingerprinting — A useful tool in fruit breeding

Summary Identification of cultivars and selections, pedigree analysis, estimation of genetic relatedness and genome mapping — all of these objects are achieved with various methods of DNA fingerprinting which can distinguish even closely related genotypes. Initial results were obtained by a variation of the well-known RFLP-technique (Restriction Fragment Length Polymorphism): hybridization of restriction enzyme-digested DNA samples with hypervariable minisatellite DNA probes. Technical improvements, including a number of additional DNA probes and various DNA fragment detection methods, have since been published. With the recent advent of the PCR technique (Polymerase Chain Reaction) and PCR-based methods like RAPD (Random Amplified Polymorphic DNA), DNA fingerprinting has widened its applicability and attracted a growing number of scientists.     

日本囊对虾基因组小卫星的特征分析

为了分析日本囊对虾基因组中小微星序列的分布特征并开发小卫星标记，构建了日本囊对虾随机基因组文库，对其中片段长度为400～1 000 bp的3 395个克隆测序，共获得总长度为1 606 711 bp的DNA序列。在序列拼接后的2 815个克隆中，筛选到487个小卫星序列，其序列总长度占测序序列总长度的3.97%。小卫星序列中，以12 bp重复单位的序列数量最多（8.62%)，总体趋势表现为重复单位越长，相应的重复序列数目越少（R=-0.826, P<0.01)。小卫星重复单位拷贝数分布范围以8 bp重复单位最广（3.1～47.6)，其次是10 bp(2.5～44)，再次是12 bp(2.2～28)。平均拷贝数最高的三种重复类型分别为8 bp重复单位（13.45)，32 bp（9.32）和7 bp（9.28）。小卫星序列重复单位的拷贝数分布范围2～48，集中分布在2～30，且表现为拷贝数目越大，其相应的重复序列数目越低的趋势。小卫星序列中，AT含量大于50%的序列占66%小卫星AT含量与相应的序列数目不相关（R=0.063,P<0.05)。小卫星侧翼序列分析表明，随着小卫星GC含量的升高，其两端侧翼序列GC含量表现为不断增大的趋势（R=0.731, P<0.01)，小卫星序列的产生与其两端侧翼序列的碱基组成可能存在一定的关系     

Polymorphisms of the growth hormone gene in domesticated red sea bream populations (Pagrus major) based on minisatellite genotypes and nucleotide sequences

The genetic diversity of the growth hormone gene in domesticated red sea bream (pmaGH) was evaluated using a minisatellite DNA marker located in intron 3 (pmaGH22) and nucleotide sequences. The number of alleles of pmaGH22 was largely decreased in domesticated strains of red sea bream, and the possibility of selection pressures was also detected based on the analysis of the Hardy–Weinberg equilibrium in some strains. However, each strain inherited a small number of alleles of pmaGH22, and the entire domesticated population (combining all strains) showed a large number of alleles (n = 17), similar to the allelic richness of the wild population (n = 18.5). Based on nucleotide sequencing analysis, three synonym mutations were found in the coding regions, and also several SNPs and indels were found in the noncoding regions. In addition, four genealogies of growth hormone haplotypes were identified based on principal coordinate analysis, and these genealogies of pmaGH partly reflected allele size ranges of pmaGH22. Several haplotypes shared alleles of pmaGH22, and also fragment size homoplasy in pmaGH22 was suspected. These alleles of pmaGH22 and the haplotypes will be a useful indicator for divergence of pmaGH and for broodstock individual selection with minimum inbreeding effect.     

家畜家禽DNA指纹图的研究进展(综述)

多种小卫星探针和微卫星探针可以用来获得家畜家禽的 DNA 指纹图谱.象人的DNA 指纹图一样,畜禽的 DNA 指纹图也具有高度的变异性和稳定的遗传性.畜禽 DNA 指纹图已广泛地用于鉴定个体、测定品种(系)的遗传纯度和品种(系)间的遗传距离、监测育种及遗传操作效应、寻找重要数量性状位点的遗传标记、开发单位点高变异探针等方面.