美国蒙大拿大学John P. McCutcheon小组发现肽聚糖（PG）可由一种昆虫和细菌嵌合体的方式产生。这一研究成果2019年10月3日在线发表在国际学术期刊《细胞》上。

研究人员发现粉蚧基因组上的水平转移基因与保留在Moranella基因组上的基因一起工作，从而只在Moranella细胞外围产生PG层。此外，研究人员表明由细菌来源的水平转移基因编码的昆虫蛋白被运输到Moranella的细胞质中。这些结果提供了与细胞器中发现的遗传和生物化学镶嵌相似的惊人结果，并证明了多个水平转移的基因可以整合到分布在动物和细菌内共生体基因组之间的功能途径之中。

研究人员介绍，PG是细菌的明确特征，参与到细胞分裂、形状和完整性。研究人员以前曾报道过，与PG生物合成有关的几个基因已从细菌水平转移到粉蚧的核基因组中。粉蚧以在特殊昆虫细胞中包含巢居的细菌内共生结构闻名，即一种细菌Moranella生活在另一种细菌Tremblaya的细胞质中。

附：英文原文

Title: Peptidoglycan Production by an Insect-Bacterial Mosaic

Author: DeAnna C. Bublitz, Grayson L. Chadwick, John S. Magyar, Kelsi M. Sandoz, Diane M. Brooks, Stéphane Mesnage, Mark S. Ladinsky, Arkadiy I. Garber, Pamela J. Bjorkman, Victoria J. Orphan, John P. McCutcheon

Issue&Volume: 3 October 2019

Abstract: Peptidoglycan (PG) is a defining feature of bacteria, involved in cell division, shape, and integrity. We previously reported that several genes related to PG biosynthesis were horizontally transferred from bacteria to the nuclear genome of mealybugs. Mealybugs are notable for containing a nested bacteria-within-bacterium endosymbiotic structure in specialized insect cells, where one bacterium, Moranella, lives in the cytoplasm of another bacterium, Tremblaya. Here we show that horizontally transferred genes on the mealybug genome work together with genes retained on the Moranella genome to produce a PG layer exclusively at the Moranella cell periphery. Furthermore, we show that an insect protein encoded by a horizontally transferred gene of bacterial origin is transported into the Moranella cytoplasm. These results provide a striking parallel to the genetic and biochemical mosaicism found in organelles, and prove that multiple horizontally transferred genes can become integrated into a functional pathway distributed between animal and bacterial endosymbiont genomes.

DOI: 10.1016/j.cell.2019.08.054

Source: https://www.cell.com/cell/fulltext/S0092-8674(19)31005-0