亚洲部分地区东方蜜蜂mtDNA多态性研究

 就云南省7个不同样点共7群东方蜜蜂蜂群开展mtDNA内切酶位点测试和分析研究,并与菲律宾的东方蜜蜂作对比分析。内切酶DraI分析7个蜂群,共发现4个内切酶位点;云南东方蜜蜂mtDNA的tRNAleu-COII基因的序列没有长度多态性,EcoRI内切酶位点共有4个,与菲律宾的吕宋岛的东方蜜蜂属于同一单倍型。另外,对来自尼泊尔、泰国、越南、老挝以及我国北京、云南等地的共13群蜜蜂mtDNA COII基因的420个碱基对进行测序分析,发现13群东方蜜蜂分析的420个碱基序列里,位点变异从0个到5个不等,变异率从0到1.19％. 用邻接法(neighbor-joining)构建的分子系统树可以看出分枝树主要分为两个类群:高纬度或高海拔的蜂群为一个类群,它们主要来自撒营盘（2）（China 4）、丽江(China 7)、北京(1)（China 1）、尼泊尔（Nepal）、北京（2）（China 2）、河口（1）（China 8）和越南（2）（Vietnam 2）。另一个类群的主要来自低纬度或低海拔的蜂群,它们主要来自撒营盘（1）（China 3）、景洪（China 5）、越南（1）（Vietnam 1）、泰国（Thailand）、河口(2) (China 6)和老挝(Laos)。该实验为我国东方蜜蜂资源的保护和开发研究提供了重要的信息和手段。     

Bayesian inference towards the resolution of molecular evolution:application to the "Trichoderma harzianum sensu lato" clade

The Hypocrea lixii/Trichoderma harzianum species aggregate contains a group of taxa (H. lixii /T. harzianum, T. aggressivum, T. tomentosum, T. cerinum, T. velutinum, H. tawa) of which some (e.g. T. harzianum) are important for biocontrol of plant pathogenic fungi in agriculture, whereas others are aggressive pathogens of Agaricus spp. and Pleurotus spp. in mushroom farms (T. aggressivum), or opportunistic pathogens of immunocompromised mammals including humans (T. harzianum). We ch…     

湖羊起源及系统地位的研究

应用中心产区典型群简单随机抽样法 ,检测控制血液酶和其他蛋白质变异的 14个结构基因座上31个等位基因的频率 ,并引用国内外 2 2个绵羊群体 11个座位的研究资料 ,以探讨湖羊的起源及系统地位。研究表明 ,湖羊与蒙古利亚的绵羊群体亲缘关系相对较近 ,两者可能在更早的世代具有共同的起源。这个结果与已知的历史事实吻合。     

湖羊蛋白酶遗传型结构及系统地位的研究

用“中心产区典型群随机抽样”的方法，对湖羊品种进行遗传检测，在所检测的12个位点中的11个（Alb,Tf,Alp,Lap,Ary-Es,Hb-β，X-p,CA,Cat,Ly和Le)具有多态性，仅Po位点为单态，多态座位比例为91．7％，在27个等位基因中，只有Po^R,Tf^A,Hb-β^A,CA^F和Fe^L的估计可靠程度分别为0.5222,0.7458,0.5222,0.6212,0.8990和0.9070外余21个等位基因估计可靠程度均在0．9545以上。说明“中心产区典型群随机抽样”在特定遗传背景下是一种有效的抽样方法。湖羊的平均杂合度比国内其他绵羊种群偏低，而与国外其他群体相比，平均纯合度偏低。引用国内外14个绵羊群体的相同资料，根据血液酶和其他蛋白质变异的10个基因座位共计33个等位基因的频率，进行系统聚类分析，表明湖羊与蒙古羊亲缘关系较近。     

天山一号冰川产淀粉酶酵母菌的筛选及其系统发育分析

[目的]筛选并分析天山一号冰川冰层产淀粉酶的低温酵母菌。[方法]对天山一号冰川冰层含冰冻土产低温淀粉酶的低温酵母菌菌株进行筛选、纯化,并对其生理多样性和系统发育多样性进行研究。[结果]从天山一号冰川冰层含冰冻土中分离出60株酵母菌,并从中筛选出6株产低温淀粉酶的菌株,根据细胞菌落形态、菌体特征和26S rDNA D1/D2区域序列系统发育分析,6株菌分别隶属于红酵母属(Rhodotorula)、隐球菌属(Cryptococcus)和掷孢酵母属(Sporobolomyces),最适生长温度为20~24℃,为兼性耐冷细菌。[结论]研究可为了解冰川酵母菌的系统发育多样性以及低温淀粉酶的生物技术研发奠定基础。     

A fine map for maternal lineage analysis by mitochondrial hypervariable region in 12 Chinese goat breeds

As the fast pace of genomic research continues to identify mitochondrial lineages in animals, it has become apparent that many independent studies are needed to support a robust phylogenetic inference. The aim of this study was thus to further characterize the maternal lineage, proposed to originate in southwestern region of China, using a wider survey of diverse goat breeds in China. To this end, we sequenced the mitochondrial hypervariable region 1 (HVR1) of the mtDNA control region in 145 goats of 12 Chinese breeds. Phylogenetic analysis revealed that Chinese goats were classified into four distinct lineages (A, B, C and D) as previously reported. A Mantel test and the analysis of Analysis of Molecular Variance (ANOVA) indicated that there was not an obvious geographic structure among Chinese goat breeds. Population expansion analysis based on mismatch distribution and Fu's Fs statistic indicate that two expansion events in Chinese goats occurred respectively at about 11 and 29 mutational time units ago, revealing two star-like subclades in lineage B corresponding to two population expansion events. Moreover, lineage B sequences were presented only in the breeds of southwestern or surrounding regions of China. Multiple lines of evidence from this study and previous studies indicate that for Chinese goats mtDNA lineage B originated from the southwestern region of China.     

The complete mitochondrial genome and molecular phylogeny of Lueyang black-bone chicken

ABSTRACT

1. The objectives of the current study were to investigate the mitochondrial genome and molecular phylogeny of Lueyang black-bone chicken, and provide molecule base to preserve and explore the specific chicken strain.

2. Based on sequencing and clustering, the complete mitochondrial DNA map and sequences of Lueyang black-bone chicken were revealed, and two phylogenetic trees of Lueyang black-bone chickens based on D-loop sequences and the mitochondrial genome were constructed.

3. The results showed that the complete mitochondrial genome of Lueyang black-bone chickens is 16,784bp in size, consisting of 22 transfer RNA genes, two ribosomal RNA genes, 13 protein-coding genes, and one non-coding control region. The base composition of the complete mtDNA sequence is 30.28% for A, 23.78% for T, 32.42% for C, 13.52% for G. Additionally, 10 haplotypes of D-loop sequences in 32 Lueyang black-bone chickens were detected, which were distributed into 4 clades (A, B, C and E).

4. It was concluded that genetic diversity is wide in Lueyang black-bone chickens, and this strain has multiple maternal origins from different regions in China and neighbouring regions.     

Genetic diversity and phylogenetic relationships between Leishmania infantum from dogs,humans and wildlife in south‐east Spain

Leishmania infantum causes human and canine leishmaniosis. The parasite, transmitted by phlebotomine sand flies, infects species other than dogs and people, including wildlife, although their role as reservoirs of infection remains unknown for most species. Molecular typing of parasites to investigate genetic variability and evolutionary proximity can help understand transmission cycles and designing control strategies. We investigated Leishmania DNA variability in kinetoplast (kDNA) and internal transcribed spacer 2 (ITS2) sequences in asymptomatically infected wildlife (n = 58) and symptomatically and asymptomatically infected humans (n = 38) and dogs (n = 15) from south‐east Spain, using single nucleotide polymorphisms (SNPs) and in silico restriction fragment length polymorphism (RFLP) analyses. All ITS2 sequences (n = 76) displayed a 99%–100% nucleotide identity with a L. infantum reference sequence, except one with a 98% identity to a reference Leishmania panamensis sequence, from an Ecuadorian patient. No heterogeneity was recorded in the 73 L. infantum ITS2 sequences except for one SNP in a human parasite sequence. In contrast, kDNA analysis of 44 L. infantum sequences revealed 11 SNP genotypes (nucleotide variability up to 4.3%) and four RFLP genotypes including B, F and newly described S and T genotypes. Genotype frequency was significantly greater in symptomatic compared to asymptomatic individuals. Both methods similarly grouped parasites as predominantly or exclusively found in humans, in dogs, in wildlife or in all three of them. Accordingly, the phylogenetic analysis of kDNA sequences revealed three main clusters, two as a paraphyletic human parasites clade and a third including dogs, people and wildlife parasites. Results suggest that Leishmania infantum genetics is complex even in small geographical areas and that, probably, several independent transmission cycles take place simultaneously including some connecting animals and humans. Investigating these transmission networks may be useful in understanding the transmission dynamics, infection risk and therefore in planning L. infantum control strategies.     

The genetic diversity and structure of 18 sheep breeds exposed to isolation and selection

The phylogenetic layout of the genotyped (30 microsatellite) 18 sheep breeds in this study demands and provides the opportunity to evaluate both neutral and adaptive components of genetic diversity in a naturally and artificially selected and subdivided sheep population. Seven Pramenka strains from Bosnia and Herzegovina and Croatia characterized by a very low intensity of artificial selection, preserved the highest neutral genetic variability. Eight central and north‐western European breeds under considerable artificial isolation and selection preserved the lowest genetic variability. Only combinations of various phylogenetic parameters offer a reasonable explanation for underlying evolutionary forces working in the investigated island and mainland sheep breeds under variable natural and artificial selection. More than 60% of total genetic, diversity was allocated to virtually unselected Pramenka strains, and an additional 25% to native moderately selected Graue Gehoernte Heidschnucke and intensively selected Ostfriesische Milchschafe. Some economically very important breeds and strains did not contribute to a pool with maximal genetic diversity, while they play an important role in the cultural heritage of respective countries.     

Influenza A Viruses Detected in Swine in Southern Germany after the H1N1 Pandemic in 2009

Infections with influenza A viruses (IAV) are highly prevalent in swine populations, and stable cocirculation of at least three lineages has been well documented in European swine – till 2009. However, since the emergence of the human pandemic pdmH1N1 virus in 2009, which has been (re)introduced into individual swine herds worldwide, the situation has been changing. These variations in the respective IAV pools within pig populations are of major interest, and the zoonotic potential of putative emerging viruses needs to be evaluated. As data on recent IAV in swine from southern Germany were relatively sparse, the purpose of this study was to determine the major IAV subtypes actually present in this region. To this aim, from 2010 to 2013, 1417 nasal swabs or lung tissue samples from pigs with respiratory disease were screened for IAV genomes. Overall, in 130 holdings IAV genomes were detected by real‐time RT‐PCR targeting the matrix protein gene. For further analyses, several PCR protocols were adapted to quickly subtype between H1, pdmH1, H3, N1 and N2 sequences. Taken together, cocirculation of the three stable European lineages of IAV was confirmed for Bavaria. H1N1 sequences were identified in 59, whereas H1N2 genomes were only diagnosed in 14, and H3N2 in 9 of the holdings analysed. However, pdmH1 in combination with N1 was detected in 2010, 2012 and 2013 confirming a presence, albeit in low prevalence, likewise pdmH1N2 reassortant viruses. Interestingly, individual cases of coinfections with more than one subtype were diagnosed. Partial genome sequences were determined and phylogenetic analyses performed. Clearly other than in the human population classically circulating IAV have not been displaced by pdmH1N1 in Bavarian swine. However, some interesting viruses were detected. Further surveillance of these viruses in the Bavarian pig population will be of major importance, to monitor future developments.