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皇冠游戏乐代理必赢网

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摘要 : 2017年8月8日,国际微生物学旗舰刊物《mBio》杂志上在线发表了华中农业大学芽胞杆菌分子生物学研究团队微生物基因组学研究论文

2017年8月8日,国际微生物学旗舰刊物《mBio》杂志上在线发表了华中农业大学芽胞杆菌分子生物学研究团队微生物基因组学研究论文“Comparative Genomics of Bacillus thuringiensis Reveals a Path to Specialized Exploitation of Multiple Invertebrate Hosts”。该研究通过比较基因组学的方法,发现了一种新的百家乐代理适应多宿主的必赢网。信息学院郑金水副教授为该论文第一作者,生科院娱乐城教授为通讯作者。

群体基因组学为人类和其他高等动物细菌病原体的形成、进化和动态变化提供了许多新的见解, 但这些研究关注的百家乐代理往往仅有非常狭窄的寄主范围。作为昆虫和线虫的病原菌, 苏云金芽胞杆菌(Bt)产生的毒素对昆虫等多种无脊椎动物的具有毒杀活性, 可作为一种模型来研究具有广泛宿主范围的病原菌的演变。比较包括所有84个亚种的标准菌株在内的130个Bt基因组,发现在基于基因组的系统发育树上, Bt宿主的特化和转换分别发生在主要和次要的分支上。毒素基因共出现网络分析表明, 具有相似靶标宿主的、且对宿主具有直接毒杀作用的多种毒素基因往往在同一细菌的基因组上大量积累。同时发现特定质粒的动态变化引起的水平基因转移是这种毒素基因积累的直接原因。这种积累可能是Bt用来对抗寄主抗性的策略之一。

研究报道的病原细菌的这种形成和进化方式,代表了一种的不同于高等动物百家乐代理进化的新模式。

原文链接:

Comparative Genomics of Bacillus thuringiensisReveals a Path to Specialized Exploitation of Multiple Invertebrate Hosts

原文摘要:

Understanding the genetic basis of host shifts is a key genomic question for pathogen and parasite biology. The Bacillus cereus group, which encompassesBacillus thuringiensis and Bacillus anthracis, contains pathogens that can infect insects, nematodes, and vertebrates. Since the target range of the essential virulence factors (Cry toxins) and many isolates is well known, this group presents a powerful system for investigating how pathogens can diversify and adapt to phylogenetically distant hosts. Specialization to exploit insects occurs at the level of the major clade and is associated with substantial changes in the core genome, and host switching between insect orders has occurred repeatedly within subclades. The transfer of plasmids with linked cry genes may account for much of the adaptation to particular insect orders, and network analysis implies that host specialization has produced strong associations between key toxin genes with similar targets. Analysis of the distribution of plasmid minireplicons shows that plasmids with orf156 and orf157, which carry genes encoding toxins against Lepidoptera or Diptera, were contained only by B. thuringiensis in the specialized insect clade (clade 2), indicating that tight genome/plasmid associations have been important in adaptation to invertebrate hosts. Moreover, the accumulation of multiple virulence factors on transposable elements suggests that cotransfer of diverse virulence factors is advantageous in terms of expanding the insecticidal spectrum, overcoming insect resistance, or through gains in pathogenicity via synergistic interactions between toxins.

doi:10.1128/mBio.00822-17

作者:娱乐城 点击:

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