烟粉虱复合种不同地理种群的遗传分化

烟粉虱Bemisia tabaci(Gennadius) 是由具有遗传分化的不同地理种群组成的复合种。本文介绍了烟粉虱不同地理种群遗传分化的最新研究进展，并在世界各国对烟粉虱核糖体ITS1(rDNA ITS1)、线粒体COI（mtDNA COI）基因大量测序的基础上，进一步分析了烟粉虱不同地理种群的遗传分化。根据mtDNA COI和rDNA ITS1基因序列分析的结果，烟粉虱不同地理种群可分为5组，即亚洲组（Asia group）、美洲组（America group）、非洲组（Africa group）、澳洲组(Australia group)、B型/地中海/中东/北非/Ms型组(Biotype B/Mediterranean/Middle Eastern/Northern Africa/Biotype Ms group)；此外，还包括3个没有特定组的种群，即乌干达（Uganda）、科特迪瓦（Ivory Coast和台湾（Taiwan）种群。地理隔离可能是造成烟粉虱不同地理种群遗传分化的最重要驱动力。许多具有入侵性或生物学优势的烟粉虱种群随着人类活动而传入新的地区，造成了严重的经济损失。有必要加强烟粉虱生物型的监测，遏制已入侵烟粉虱种群的蔓延，防止新的具有潜在危险性的烟粉虱种群传入中国。     

甘蓝胞质雄性不育系育性相关线粒体DNA片断的克隆及序列分析

以甘蓝结球期叶球内叶为试材,利用PCR方法在甘蓝新型胞质雄性不育材料CMS451的线粒体基因组中扩增出与细胞质雄性不育相关的片断,并克隆测序.结果表明:该片断和NCBI发布的Ogura胞质不育系特异片段高度同源,说明CMS451的不育机理与Ogu-CMS相似,也反映了CMS基因的相对保守性.     

Classification and Genetic Diversity of Three Hare Species in Xinjiang Based on Mitochondrial DNA

The study aimed to explore the phylogeny and genetic diversity of 3 hare species in Xinjiang by molecular genetics methods, define the relationship and taxonomy status, assess diversity level of Lepus in Xinjiang, and provide the basic data for conservation genetics of hares in Xinjiang and even in China. Three mitochondrial DNA genes, COI, ND4 and 16S rRNA, were used as molecular markers, and the sequences of 3 genes of 57 samples collected from 8 different regions (4 geographic groups) in Xinjiang were determined by PCR amplification and sequencing technology. After the sequences of COI, ND4 and 16S rRNA of each sample were revised and pooled together, data were analyzed with softwares such as MEGA 7, DNAsp 6, Arlequin 3.1 and MrBayes 3.2. A total of 43 haplotypes were detected from the combined sequences of 3 genes of 57 hare samples. Five distinct clades (A-E) and 3 clusters were clearly showed in phylogenetic tree and median-joining network (MJN). Furthermore, the genetic distance between 3 clusters reached the level of species (4.21%-9.09%). However, the genetic distance between hares from northern Xinjiang (Clade E) and those from central Xinjiang (Clade D) were not up to the level of species (≤2.26%) in the third cluster. The haplotype diversity (h) of Lepus yarkandensis, Lepus tibetanus pamirensis and Lepus tolai lehmanni were higher(0.979±0.014, 0.972±0.064 and 0.972±0.064, respectively), while the nucleotide diversity (π) of the L. t. lehmanni and L. t. centrasiaticus were higher (0.033±0.018 and 0.023±0.015, respectively). Based on comprehensive analysis of 3 genes of mitochondrion and reference with published research, it is suggested that hares from southwestern Pamir Plateau of Xinjiang should belong to L. t. pamirensis. Meanwhile,hares distributed in northern and central Xinjiang might be considered as L. t. lehmanni and L. t. centrasiaticus. Moreover, there is abundant genetic diversity in the 3 hare species in Xinjiang, and the obvious phylogeographic pattern is showed.     

西藏牦牛12SrRNA基因全序列测定及系统进化关系

以西藏11个地区的牦牛类群共计110头为研究对象,采用PCR方法,首次从耳组织总DNA中扩增出了线粒体12SrRNA基因,并进行了序列测定及分析。结果表明,该基因的长962～965bp;序列分析表明12SrRNA基因有较高的进化速率,11个地区的牦牛品种同源性相对较高;对11种类群的牦牛及亚洲水牛、非洲水牛、欧洲野牛和家牛四种牛亚科的12SrRNA基因序列建立NJ和ME分子进化树,结果显示帕里牦牛、斯布牦牛、巴青牦牛、丁青牦牛、江达牦牛、工布江达牦牛、康布牦牛与桑日牦牛的亲缘关系最近。     

DNA技术在羊毛羊绒鉴别中的应用

羊绒与羊毛的鉴别一直是当前面临的难题,以DNA为基础的检测方法由于准确灵敏,目前已成为毛绒鉴别中最可靠的方法。文中对毛绒的DNA鉴别方法及难点进行了综述,以期为毛绒准确鉴别提供参考。     

Extreme neutral genetic and morphological divergence supports classification of Adriatic three-spined stickleback (Gasterosteus aculeatus) populations as distinct conservation units

The fact that the intraspecific genetic differentiation in neutral genetic markers and genes coding for adaptive traits are not typically correlated has caused a great deal of conceptual and practical trouble in delimitation of conservation units. Although the importance of combining information on adaptive genetic divergence with information on historical and recent gene flow in the delimitation of conservation units has been recognized, integrated empirical studies to this end are still rare. We explored the evidence for the specific conservation status of two freshwater three-spined stickleback (Gasterosteus aculeatus) populations on the Adriatic side of the Balkan Peninsula by comparing their phenotypic and genetic characteristics to those of other representative European populations. Apart from focusing on the neutral genetic divergence in mitochondrial DNA sequences and microsatellite markers, we also compared the patterns of morphological differentiation (i.e. bony armour development) resulting from adaptation to freshwater environments. The Balkanic populations formed two distinct groups with regard to neutral genetic variation and had the least developed bony armour of all the examined populations. All morphometric analyses identified the two Balkanic populations as phenotypically – and hence most likely also ecologically – clearly distinct from other European three-spined stickleback populations. These results suggest that the two Balkanic populations (River Neretva and River Zeta) fulfil the most stringent criteria (i.e. lack of genetic and ecological exchangeability) to be classified as conservation units distinct from other European three-spined stickleback populations.     

建昌马mtDNA D-loop区遗传多样性及系统进化分析

试验旨在以线粒体DNA(mitochondrial DNA,mtDNA)为切入点,研究建昌马的母系遗传多样性与系统进化。从建昌马(n=39)血液中提取基因组DNA,用PCR方法扩增mtDNA D-loop区并直接测序,分析其高变区247 bp序列信息,统计mtDNA D-loop区的单倍型及变异位点,计算单倍型多样性(haplotype diversity,Hd)、核苷酸多样性(nucleotide diversity,Pi)和平均核苷酸变异数(average number of nucleotide differences,K)。构建包括建昌马在内的19个品种马的NJ系统进化树,计算各品种间的遗传距离。结果显示,试验获得了清晰的PCR扩增产物,并通过直接测序方法获得了约1200 bp的序列。39匹建昌马mtDNA D-loop区247 bp序列(其中1个样品缺失1 bp)的AT碱基含量为61.45%,属AT碱基对富集区,检测到33个多态性位点,共显示26种单倍型,其中4种为共享单倍型,且Hap7和Hap1为优势单倍型,单倍型多样性为0.947,核苷酸多样性为0.02399,平均核苷酸变异数为5.901,显示丰富的母系遗传多样性;NJ系统进化树显示,建昌马分布在A、C、D、E、F、G共6个支系中,约50%的样品分布在A支系,显示出复杂的母系起源;建昌马与关中马的遗传距离最小(0.021),其次是三河马、文山马、韩国车巨马(0.024),与韩国济州岛马遗传距离最大(0.032)。本研究结果表明,建昌马的mtDNA D-loop高变区遗传多样性丰富,具有多个母系起源,且A支系占有明显优势,与关中马、文山马可能有共同的母系起源。     

中国家鸡和红色原鸡mtDNA控制区遗传多态性及系统进化分析

通过线粒体DNA控制区的结构和多态性来研究中国家鸡和红色原鸡的遗传多态性与系统进化。测定14个中国地方鸡种和红色原鸡2个亚种的256个个体线粒体DNA控制区部分序列约560bp,结果表明,A、C、G、T这4种核苷酸的平均比例分别为25．∞％、37．40％、4．40％和33．20％。共发现44个变异位点,约占分析位点总数的7．86％,没有观测到插入／缺失,颠换和转换之比为0．13;共具有32种单倍型,9种为共享单倍型;16个群体内单倍型多样度从0到0．964,单倍型变异度总体为0．909±0．014,整体的平均核苷酸差异数为7．276,核苷酸多样度为1．851％。群体间核苷酸分歧度（Dxy）在0．747％～3．125％之间变化,核苷酸净遗传距离（Da）为0．015％～2．633％。16个群体表现出较高水平的遗传多态性,群体间表现出显著的遗传分化。群体遗传多态性和亲缘关系分析表明,一些中国家鸡的群体（如固始鸡和仙居鸡）起源于泰国红色原鸡Gallus gallu sgallus亚种,一些中国家鸡的群体（如茶花鸡和藏鸡等）起源于中国红色原鸡Gallus gallus spadiceus亚种,在一些中国地方鸡种还同时具有这2种红色原鸡的遗传贡献;认为中国家鸡起源于泰国或单纯起源于中国的观点都是不全面的。     

贵州下司犬线粒体DNA控制区核苷酸序列分析

采用聚合酶链式反应和直接测序的方法,分析了贵州下司犬线粒体D-loop区序列。结果显示,该犬的线粒体D-loop全长1260bp,碱基序列中A、T含量明显高于G、C含量。其中有一段以串连方式排列、重复29次的序列,重复单元为TACACGT(A/G)CG。对该串连重复序列上游673bp的碱基序列进行分析,比较已知犬种相应碱基序列之间的差异,聚类分析结果显示下司犬与亚洲犬种的亲缘关系较近。     

Genetic diversity of Bangladeshi native chickens based on complete sequence of mitochondrial DNA D-loop region

ABSTRACT

1. The aim of this study was to explore genetic diversity and possible origin of Bangladeshi (BD) native chickens. The complete mtDNA D-loop region was sequenced in 60 chickens representing five populations; naked neck, full feathered, Aseel, Hilly and autosomal dwarf. The 61 reference sequences representing different domestic chicken clades in China, India, Laos, Indonesia, Myanmar, and other Eurasian regions were included. The mtDNA D-loop sequence polymorphism and maternal origin of five BD populations were analysed.

2. A total of 35 polymorphic sites, and 21 haplotypes were detected in 60 mtDNA D-loop sequences. The haplotype and nucleotide diversity of the five populations were 0.921 ± 0.018 and 0.0061 ± 0.0019, respectively. Both mtDNA network and phylogenetic analysis indicated four clades (four haplogroups) in BD populations (21 haplotypes) along with 61 reference haplotypes. Clade E contained the most individuals (20) and haplotypes (11) of BD chickens, followed by clade D (17, 6), clade C (12, 2) and clade F (11, 2), respectively.

3. The higher number of unique haplotypes found in Yunnan, China, suggested that the origin of BD chickens was in this region. The haplotypes from different haplogroups were introduced in Bangladeshi chickens from India, China and Myanmar. The phylogenetic tree showed a close relationship of BD chickens with the clusters from India, China, Myanmar and Laos, and indicated the dispersion of BD chickens from these sources. The phylogenetic information revealed high genetic diversity of BD chickens because of their origin from different lineages with high genetic variation and distance, which was determined from four cluster and neighbour-joining trees.

4. In conclusion, BD populations had high genetic diversity. The mtDNA network profiles and phylogenetic trees showed multiple maternal origins of BD chickens from India, China, Myanmar and Laos.