Insect-bacterial mosaic produces peptidoglycan in mealybug
Insect-bacterial mosaic produces peptidoglycan in mealybug
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昆虫细菌嵌合体在粉蚧中产生肽聚糖
DOI：
10.1080/20477724.2019.1706711
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发表时间：
2019
影响因子：
3.4
通讯作者：
Favia G
中科院分区：
文献类型：
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作者：
Favia G
10月，Cell发表了一篇有趣的论文，描述了一种功能性的生物合成途径，该途径由粉蚧Planococcus citri及其细菌的一种内共生体编码的基因组合组成，从而显示出与细胞器进化的显著而有趣的相似性[1]。粉蚧（Planococcus citri）是一种非常有趣的研究微生物共生的生物，实际上这种昆虫宿主两种细菌内共生，一种（Moranella）生活在另一种（Tremblaya）体内。更有趣的是，粉蚧共生体Tremblaya princeps （PCIT）拥有最小的基因组，由129千碱基组成，PCIT基因组的减少与Moranella[2]的存在显著相关。Bublitz和他的合作者发现水平转移到p.s citri基因组的基因与维持在Moranella基因组上的基因协同作用，产生肽聚糖（PG）层，然后只定位在内共生体的细胞外围。PG对于维持细菌细胞形状和防止肿胀至关重要，它具有基本的组成，在所有细菌中都可以识别，尽管已经描述了一些物种特异性变异，它们可能影响细菌的致病性。昆虫具有肽聚糖识别蛋白（PGRP），这对于检测病原体相关的分子模式至关重要，并参与抗菌反应的激活。虽然作者没有指出PG层的功能作用，但他们从对质体的研究中推断，从其内共生体中获取PG可能是调节细菌细胞分裂的关键因素。有趣的是，在这篇文章中，作者引用了De Vries和Gould（2018）的一篇论文，该论文在苔藓中展示了核基因组上pg相关的HGT（水平基因转移）的敲除了如何导致叶绿体[5]的大小增加。
In October, Cell published an intriguing paper describing a functional biosynthetic pathway constituted from a combination of genes encoded by both the mealybug Planococcus citri and one of its bacterial endosymbionts, thus showing a remarkable and interesting parallelism to organelle evolution [1]. Mealybug (Planococcus citri) is a very interesting organism in which to study microbial symbiosis, in fact this insect hosts two bacterial endosymbionts, one (Moranella) living inside the other one (Tremblaya). Even more interesting, the mealybug symbiont, Tremblaya princeps (PCIT) has the smallest reported genome, which consists of 129 kilobases and the PCIT genome reduction is significantly related with the presence of Moranella [2]. Bublitz and collaborators [1] show that genes horizontally transferred to the P. citri genome act synergistically with genes maintained on the Moranella genome to produce a peptidoglycan (PG) layer that then localizes only on the cell periphery of the endosymbiont.PG is essential to maintain the bacterial cell shape and protect from turgor, it has a fundamental composition, identifiable in all bacteria, although some species-specific variations have been described and they may impact on the pathogenicity of the bacteria [3]. Insects have Peptidoglycan Recognition Proteins (PGRP) that are critical for the detection of pathogen associated molecular patterns and are involved in the activation of anti-bacterial responses [4]. Though the authors do not indicate the functional role of the PG layer, they infer from studies on plastids that the PG takeover from its endosymbiont can represent a critical element in the regulation of the cellular division of the bacteria. Interestingly, in this article the authors refer to a paper by De Vries & Gould (2018) which in moss showed how the knock-out of a PG-related HGT (horizontal gene transfer) on the nuclear genome results in an increased size of chloroplast [5].
影响因子：
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作者：
M. Pazos;K. Peters
通讯作者：
M. Pazos;K. Peters