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1.
牛亚科MHC DRB3基因exon2的序列变异分析 总被引：12，自引：0，他引：12
根据牛（Bos taurus）主要组织相容复合体（MHC）DRB3基因的已知序列设计引物，对中国牦牛（B．grunniens）的DRB3基因exon2进行扩增和克隆测序，并根据DRB3基因exon2序列对牛亚科的遗传多样性和分子系统发育进行了分析。结果在234的片段中发现有115个多态位点，多态位点百分率为49．15％。由标准遗传距离和净遗传距离构建的牛亚科系统发育树，可将牛亚科分为5个属，支持将牦牛作为牛亚科中一个独立的属的观点。多态性较丰富的DRB3基因exon2适于属间系统发育分析。 相似文献
2.
鲤鱼品系的部分线粒体序列的遗传变异 总被引：1，自引：0，他引：1
运用PCR测序法,以9个我国常见鲤鱼（Cyprinus carpio）养殖品种和2个野生群体为研究材料,分析线粒体DNA的16S rRNA、Cyt b和D-loop序列片段,用于分析的序列共有1 457 个位点,其中变异位点32个,简约信息位点21个,共有单倍型16个。分别利用以上3个基因片段以及合并后的序列, 构建NJ和MP进化树。由不同方法获得相似的进化树,由不同基因片段得到的进化树均为两支,其中贝尔湖野鲤（BE）单独成支,其它群体聚为1支,只是由D-loop得到的进化关系更为详细,而由合并后的序列构建的进化树也与利用不同基因序列所得到的进化树并不矛盾。各品系间的分化时间约为3.03×104～1.21×105年前。根据序列的特征,16S rRNA的1个变异位点、Cyt b基因的4个变异位点和D-loop的14个变异位点可以作为鉴定不同的养殖品系和野生群体的SNP,证明mtDNA序列分析可以应用于品系的鉴定。 相似文献
3.
月季切花衰老相关基因的差异显示及其序列分析 总被引：4，自引：0，他引：4
摘要：通过对不同瓶插寿命切花月季（Rosa hybrida）品种的DDRT-PCR方法，从长寿命的Pavarotti花瓣中扩增出22条cDNA特异片段，共得到9个cDNA片段的克隆，分别命名为b21、b32（b33）、b43、b51（b52、b814）、b618（b101、b108、b813）、b624、b131、b134和b186。序列测定和同源性检索的结果表明，来自b6的2个克隆b618和b624的序列不同，其中一个片段b618为439 bp，其氨基酸序列与拟南芥（Arabisopsis thaliana）、柑橘（Citrus sinensis）、萝卜（Raphanus sativus）、苹果（Malus sp.）、葡萄（Vitis vinifera）和胡颓子（Elaeagnus umbellata）等查尔硐异构酶(CHI)相应区域的同源性为71%~79%；另一个片段b624为440 bp,其氨基酸序列与拟南芥、豌豆（Pisum sativum）、欧洲油菜（Brassica napus）等的磷酸乙酰胆碱胞苷转移酶(CPCT)相应区域的同源性高达86%~90%。RT-PCR验证表明这2条cDNA片段为阳性结果。CHI涉及类黄酮色素的生物合成途径，CPCT参与胞苷二磷酸胆碱的合成途径，二者均与衰老进程相关。 相似文献
4.
3种野鲮亚科鱼类线粒体细胞色素b基因序列分析及种质鉴定 总被引：2，自引：0，他引：2
鲮、麦瑞加拉鲮和露丝塔野鲮隶属鲤形目（Cypriniformes）鲤科（Cyprinidae）中的野鲮亚科（Labeoninae）.这三种鱼类种苗外形相似,仅凭形态上的差别难以区分,而在实际生产、种苗引进及苗种放流时需要进行严格的鉴定.本研究利用PCR-RFLP技术对鲮、麦瑞加拉鲮和露丝塔野鲮进行种苗鉴定的分析,并利用三种鱼类cyt b基因序列的差异进行亲缘关系分析. 相似文献
5.
为判断浙江乐清铁皮石斛（Zhejiang Dendrobium officinale）与石斛属（Dendrobium）其它物种的亲缘关系,本文提取了该石斛鲜样的DNA,利用真核生物ITS序列通用引物ITS4/ITS5进行了扩增,并将扩增产物连接转化至大肠杆菌,在对阳性克隆测序。将得到的序列与GenBank上我国石斛属12个组中34个种的rDNAITS进行了比对,并在此基础上构建了系统发育树。序列比对结果表明浙江乐清铁皮石斛的rDNAITS与黄石斛（D.tosaense）一致,其次与铁皮石斛（D.officinale）最相近,序列相似性99%。系统发育树也表明浙江乐清铁皮石斛的rDNAITS序列与黄石斛（D.tosaense）的相似程度高于其与铁皮石斛（D.officinale）的相似程度。本研究将为利用ITS序列鉴别石斛物种种属关系提供参考。 相似文献
6.
查尔酮合成酶（chalcone synthase,CHS）是类黄酮生物合成的关键酶,在植物发育、防止UV损伤、抗病和逆境反应中起着重要作用。本研究通过EST测序,获得了罗汉果查尔酮合成酶基因序列（登录号：GU980155）。为了进一步了解罗汉果查尔酮合成酶基因的特征,我们将其与46种植物的查尔酮合成酶基因的核酸序列和氨基酸序列进行比对和进化分析。结果表明,罗汉果查尔酮合成酶基因的核酸序列和氨基酸序列与其它物种的查尔酮合成酶基因均具较高同源性,编码区相似性约为94%。使用PHYLIP和MEGA4分别构建了邻接树、最大似然树和最大简约树,但经bootstrap检验,最优树未能明确罗汉果查尔酮合成酶基因的系统发育地位。以紫花苜蓿查尔酮合成酶的三维结构为参考,利用同源建模的方法预测了罗汉果查尔酮合成酶的三维结构,发现罗汉果查尔酮合成酶具有保守的活性位点和空间结构。 相似文献
7.
杏自交不亲和相关S-RNase基因的克隆及表达 总被引：12，自引：0，他引：12
摘要: 从巴旦水杏(Prunus aremeniaca L. cv. Badanshui)、红玉杏(P. aremeniaca L. cv. Hongyu)和凯特杏(P. aremeniaca L. cv.Katy)3个品种中通过RT-PCR和RACE克隆出3个S-RNase片段， 分别被定名为PA1、PA2、PA3，片段大小分别为576、601和591 bp。3个基因的氨基酸的相似性达80.6%。将这3个基因与蔷薇科中其它树种的S- RNase比较表明，蔷薇科S-RNase的氨基酸序列变异很大，亚科内的相似性高于亚科间的，在所编码的187个氨基酸中只有14个氨基酸残基是完全保守的，高度变异（RHV）区PA1有H、M两个残基和PA3有N、S、A 3个残基不同于其它的S-RNase，这表明不同的残基可能起着S-等位基因专一性识别的作用。从蔷薇科、茄科及一些S-like RNase 的系统树分析可看出，苹果和梨分属于苹果亚科类，樱桃、扁桃和杏分属于李亚科类，同时也证明了实验中所得到的3个氨基酸序列是S-RNase的一个分支而不是S-like RNase的分支。 Northern 杂交分析表明凯特杏表达的PA3只在花柱中专一表达，在根、茎和叶中未表达，杂交斑的分子量为0.9 kb。序列分析及在基因库中搜索结果证明，本研究所得到的3个基因是S-RNase表达的基因。 相似文献
8.
本文运用PCR产物直接测序法对巴山榧树10个地理种群的trnL-trnF序列进行了测定,并调用GenBank中6个近缘种的trnL-trnF序列,选用MEGA 4.1软件对巴山榧树不同地理种群及近缘种间的trnL-trnF序列进行分析。结果表明,巴山榧树10个地理种群间的遗传分化程度较低,只有34个变异位点,1个信息位点;7个近缘种间的遗传分化较显著,有75个变异位点,30个信息位点。聚类分析将巴山榧树10个地理种群与6个近缘种聚为2个分支,巴山榧树、云南榧和日本榧树聚为一支,榧树、长叶榧树、佛罗里达榧和加州榧聚为另一个分支。trnL-trnF序列系统树不支持将榧树属分为皱乳榧组和榧树组;赞同将云南榧并入巴山榧树,或作为巴山榧树的变种处理;不支持将巴山榧树和云南榧合并在榧树下作为变种的处理意见。 相似文献
9.
采用mtDNA D-环序列和微卫星DNA两种标记方法,对9个绵羊群体225只个体进行遗传多样性和系统发育分析。结果表明：两种方法在遗传多样性分析中得出的结论一致,即在研究的9个绵羊群体中青海藏羊的遗传多样性最丰富,而湖羊和岷县黑裘皮羊遗传多样性都较低。但在系统发育分析中,通过mtDNA D-环序列和微卫星DNA座位数据构建系统发育树,结果表现为很大的不同。由于微卫星DNA符合孟德尔遗传规律,能够反映群体间的亲缘关系,构建的系统发育树结构可靠。mtDNA是核外遗传物质,具有母系遗传的特点,在反映群体间的亲缘关系上不具优势。此外,青海细毛羊和甘肃高山细毛羊的育种实践表明它们的遗传来源相似,亲缘关系相近,这与微卫星DNA座位数据构建系统发育树反映的结果一致,因此,在群体的亲缘关系研究上,微卫星DNA数据分析的结果比mtDNA序列分析结果更可信。172个单倍型序列网络关系分析表明研究的9个绵羊群体可能有三个母系起源。 相似文献
10.
基于STK激酶保守结构域克隆香蕉R基因和RLKs同源序列* 总被引：1，自引：0，他引：1
利用抗病候选基因（Candidate resistant gene analogs,RGAs）克隆法是获得香蕉RGAs的一条简捷而有效的途径,该法已从14种植物中获得了RGAs,发现的大多数R基因都是受体样蛋白激酶（receptor-like protein kinase,RLKs）,并具有丝氨酸/苏氨酸蛋白激酶（serine/threonine protein kinase,STK）结构域（Feuillet et al.,2001,）.本研究利用STK类R基因的STK蛋白激酶保守结构域合成简并引物,扩增香蕉主栽品巴西香蕉基因组DNA,获得RGAs同源序列和STK蛋白激酶家族基因同源序列,对于研究香蕉STK类R基因的起源和进化,利用分子标记辅助育种以及香蕉抗病信号传导机制研究和R基因的克隆将提供重要的背景. 相似文献
11.
Identifying earthworms through DNA barcodes 总被引：1，自引：0，他引：1
With almost 3000 species, earthworms provide important model systems for studying soil fauna. However, species identification of earthworms is difficult and therefore limiting. The use of DNA barcodes, which are short sequences from standardized regions of the genome, has been regarded as a promising approach to resolve this taxonomic dilemma. We evaluated sequence diversity in the mitochondrial cytochrome-c oxidase I (COI) gene as a tool for resolving differences among species of Chinese earthworms. Members of six genera and 28 species were examined, and species were successfully discriminated in all cases. Sequence divergence within species was generally less than 1%, whereas divergence between species was greater than 15% in all cases. Divergence among individuals of Eisenia fetida were much higher (up to 7.8%); however, this may represent the presence of unrecognized sibling species or subspecies. We conclude that although it cannot completely replace taxonomy, the DNA barcode is a powerful tool for identifying species of earthworms and provides a useful complement to traditional morphological taxonomy. 相似文献
12.
DNA条形码技术能够快速、准确地识别物种,对于开展基础性的分类学研究和应用性的生物多样性研究极为重要。本文以广西畜牧研究所牧草种质资源圃的8个物种共22个品种为材料,进行植物条形码ITS测序。PCR结果显示ITS的扩增成功率达到100%,同源性的分析表明各物种中的ITS序列变异显著,共找到99个可以用来区分物种的变异位点,系统进化树的结果表明利用ITS序列进行物种水平鉴定成功率达100%,能够作为DNA条形码识别植物物种。 相似文献
13.
Francesco Frati Ilaria Negri Pietro P. Fanciulli Marco Pellecchia Vincenzo De Paola Valerio Scali Romano Dallai 《Pedobiologia》2004,48(5-6):461-468
The Gram-negative -Proteobacterium Wolbachia pipientis has been described as an obligate endosymbiont in many arthropod species, where it induces a variety of reproductive alterations, including parthenogenesis. Recently, this microorganism has also been detected in the parthenogenetic collembolan Folsomia candida. Here, we confirm the occurrence of the endosymbiont also in two Italian parthenogenetic populations of F. candida using ultrastructural (electron microscopy) and molecular (PCR screening on two bacterial genes) evidence. The strain isolated in the Italian populations has almost-identical gene sequences compared to that previously isolated in other populations of F. candida. In addition, we discovered a population of Folsomia cf. candida, which showed the presence of both males and females. This population is not infected by Wolbachia. A screening of two mitochondrial genes (COI and COII) showed that the bisexual population has high levels of genetic divergence in comparison with the parthenogenetic ones, even suggesting the possibility that it belongs to a different species. Furthermore, the remarkably high levels of genetic divergence between the two parthenogenetic populations suggests a possible influence of Wolbachia on inducing such differentiation, and, in the long term, speciation. 相似文献
14.
15.
The amphidiploid species Brassica carinata A. Braun is believed to have originated in the plateaus of Ethiopia and has been cultivated there as an oilseed crop since antiquity. The species possesses agronomically important genes of rare occurrence. Although there is a large number of collections in Ethiopia, information on the extent of their genetic diversity is very limited. Thirty-six accessions of ecologically diverse regions were tested at three locations and multivariate analyses on 13 morphological and seed characters were performed. There was generally a large amount of divergence in all characters. Geographic isolation of genes, however, was not observed. Both principal component and cluster analyses disclosed complex relationships among the accessions and characters. Accessions with potential genes of interest to improve earliness, yield components and oil and protein contents have been identified. Length of growing period and yield components contributed most for divergence and clustering pattern. Oil, glucosinolate and protein contents also varied among the accessions but not so much between clusters. Increasing protein in high-glucosinolate genotypes reduced oil content and should be more efficient in genotypes of low-glucosinolate genetic background. 相似文献
16.
Genetic and morphological divergence in island and mainland birds: Informing conservation priorities
Rachael Y. Dudaniec Beth E. Schlotfeldt Terry Bertozzi Stephen C. Donnellan Sonia Kleindorfer 《Biological conservation》2011,144(12):2902-2912
Evolutionary processes can complicate conservation efforts for species with uncertain taxonomic classifications and discrete geographic populations. Discordant morphological and genetic patterns across the geographic range of species further calls for the identification of evolutionary significant units for conservation. Using island and mainland populations of a small Australian passerine (the superb fairy-wren, Malurus cyaneus), we examine the relationship between morphological and genetic divergence among two subspecies, M. c. ashbyi (Kangaroo Island, South Australia) and M. c. leggei (South Australia, mainland), using eight microsatellite markers. Island birds showed clear evidence for morphological divergence, with a larger body size and thinner bill compared to mainland birds. Two genetic clusters were found using Bayesian methods, comprising mainland and island regions. Estimates of recent migration rates between all sites were very low (<2%). Morphological and genetic differentiation between island and mainland sites correlated significantly, but not when controlling for isolation by distance. Genetic and morphological substructure was evident with three distinct genetic clusters in each region. Males, the highly sedentary sex, appeared to drive correlations between morphological and genetic differentiation. Our study provides evidence that the subspecies classification of M. cyaneus in island and mainland regions encapsulates two independently diverging populations that can be recognised in conservation planning. 相似文献
17.
Isozyme studies of genetic diversity and evolution in Hippophae 总被引：4，自引：0，他引：4
Summary To provide information on the genetic variation, differentiation and evolution in Hippophae seed samples of 25 populations from China, Finland and Russia were electrophoretically analyzed. Of six loci investigated, four were good genetic markers for identifying species and subspecies. The percentages of polymorphic loci per population were 40.3% and 62.5% at 0.95 and 0.99 polymorphic criteria respectively. The mean number of alleles per locus per population was 2.1. Total genetic diversity in the material was 0.4614. Genetic diversity partitioning showed that there was a large amount of diversity residing within geographical populations (0.1354), between subspecies within species (0.1046) and between species (0.2566) but not between geographical populations (0.0114). There were nearly twice as many negative fixation indices as positive ones in Hippophae populations. The phylogenetic tree agreed very well with botanic classifications of the species and subspecies and their geographical distributions, and quantitatively presented the genetic relationships of 25 populations. A detailed view of the evolutionary stages in Hippophae showed clearly a general decline of similarity as evolutionary divergence continued, which further explained the evolution process in Hippophae. 相似文献
18.
We carried out a comparative study using mtDNA (COI) for two free-living, endemic, terrestrial invertebrate taxa—the springtail Gomphiocephalus hodgsoni (Hypogastruridae) and the mite Stereotydeus mollis (Penthalodidae) collected from sites throughout Victoria Land and the Queen Maud Mountains, Antarctica. Maximum likelihood (ML) analyses revealed low levels of intraspecific substructuring for G. hodgsoni (?2% sequence divergence) with groups mostly corresponding to geographic location. Other well-defined (morphological) species within the Hypogastruridae ranged from 15% to 22% sequence divergence relative to G. hodgsoni. In contrast, ML analyses for S. mollis showed considerably higher levels of intraspecific divergence (up to 18% sequence divergence), suggesting the presence of morphologically cryptic species. Other presently described mite species were also readily discernible (14-18% sequence divergence). Within both G. hodgsoni and S. mollis there were three main groups corresponding to: (1) Taylor Valley; (2) Beaufort Island; and (3) Ross Island together with the adjacent continental sites. We suggest that a common pattern of climatic and geological history over long-term glacial habitat fragmentation have determined the similar geographic and haplotype distributions found for both species. However, a large variation in substitution rate, around eight times slower for G. hodgsoni, compared to S. mollis, may be due to their different life history strategies on the Antarctic continent. 相似文献
19.
Jérôme M Lemaire C Bautista JM Fleurence J Etienne M 《Journal of agricultural and food chemistry》2003,51(1):43-50
The DNA sequence diversity of Sardina pilchardus (Walbaum, 1792) and some closely related species of Clupeomorpha was investigated using the mitochondrial DNA gene encoding cytochrome b. The nucleotide sequences of complete and partial mtDNA cytochrome b were determined in numerous specimens. Sequence divergence between species and genera was evenly distributed in the cytochrome b gene but rather high compared to reports for other fish species. Phylogenetic analyses on complete cytochrome b were used to study the relationships among the considered species. S. pilchardus was easily differentiated, showing a genetic distance of 0.25 with respect to Clupeidae species and 0.26 with respect to the other species. A species-specific short fragment (<150 bp) was isolated by polymerase chain reaction (PCR) using primers designed for Clupeomorpha. A rapid and reliable PCR method using restriction fragment length polymorphism (RFLP) with two restriction enzymes (MnlI/HinfI) was optimized for unambiguous differentiation of S. pilchardus from the other species tested (raw and canned products). 相似文献
20.
The red kite (Milvus milvus) occurs in a relatively small area in the southwestern Palearctic region, with population strongholds in Central Europe. Following strong human persecutions at the beginning of the 20th century, populations have receded, particularly in peripheral areas and islands. In order to describe and compare levels of genetic diversity and phylogeographic patterns throughout its entire distribution in Europe, sequence variation of a 357 bps part of the mitochondrial DNA control region was assessed in eight populations and 105 individuals. Overall, results indicate that population declines have affected red kite mtDNA variation. We found low levels of genetic diversity (values of nucleotide diversity ranging from 0 in Majorca island to 0.0062 in Central Europe), with only 10 distinct haplotypes, separated by low levels of genetic divergence (mean sequence divergence = 0.75%). Highest haplotype and nucleotide diversities match with demographic expectations, and were found in Central European and Central Spanish samples, where present strongholds occur, and lowest values in the declining southern Spanish and insular samples. Φst estimates indicated moderate gene flow between populations. Phylogeographic patterns and mismatch distributions analyses suggest central European regions may have been colonized from southern glacial refugia (in the Italian or Iberian peninsulas). Interspecific phylogenetic comparisons and divergence date estimates indicated the genetic split between the red kite and its closely related species, the black kite (Milvus migrans), might be relatively recent. The low level of genetic variation found in the red kite mitochondrial control region, compared to the black kite, is likely the result of relatively recent divergence (associated with founder events), successive bottlenecks and small population sizes. As there are several ongoing projects aimed at reinforcing populations in countries such as the United Kingdom, Italy or Spain, our results may prove useful for the genetic management of the species. 相似文献