Gupta Manisha, Kaur Rajbir, Gupta Ankita, Raychoudhury Rhitoban
Indian Institute of Science Education and Research Mohali (IISER-Mohali) Manauli India.
Indian Institute of Science Bengaluru India.
Ecol Evol. 2021 Oct 16;11(21):14490-14508. doi: 10.1002/ece3.8108. eCollection 2021 Nov.
Maternally inherited endosymbionts of arthropods are one of the most abundant and diverse group of bacteria. These bacterial endosymbionts also show extensive horizontal transfer to taxonomically unrelated hosts and widespread recombination in their genomes. Such horizontal transfers can be enhanced when different arthropod hosts come in contact like in an ecological community. Higher rates of horizontal transfer can also increase the probability of recombination between endosymbionts, as they now share the same host cytoplasm. However, reports of community-wide endosymbiont data are rare as most studies choose few host taxa and specific ecological interactions among the hosts. To better understand endosymbiont spread within host populations, we investigated the incidence, diversity, extent of horizontal transfer, and recombination of three endosymbionts (, and ) in a specific soil arthropod community. strains were characterized with MLST genes whereas 16 gene was used for and . Among 3,509 individual host arthropods, belonging to 390 morphospecies, 12.05% were infected with , 2.82% with and 2.05% with . Phylogenetic incongruence between host and endosymbiont indicated extensive horizontal transfer of endosymbionts within this community. Three cases of recombination between supergroups and eight incidences of within-supergroup recombination were also found. Statistical tests of similarity indicated supergroup A and show a pattern consistent with extensive horizontal transfer within the community but not for supergroup B and . We highlight the importance of extensive community-wide studies for a better understanding of the spread of endosymbionts across global arthropod communities.
节肢动物的母系遗传内共生菌是细菌中数量最为丰富、种类最为多样的群体之一。这些细菌内共生菌还表现出广泛的水平转移，转移至分类学上无关的宿主，并在其基因组中广泛重组。当不同的节肢动物宿主在生态群落中接触时，这种水平转移会增强。较高的水平转移率也会增加内共生菌之间重组的可能性，因为它们现在共享同一宿主细胞质。然而，关于整个群落内共生菌数据的报道很少，因为大多数研究只选择了少数宿主分类群以及宿主之间特定的生态相互作用。为了更好地理解内共生菌在宿主种群中的传播情况，我们调查了特定土壤节肢动物群落中三种内共生菌（、和）的发生率、多样性、水平转移程度和重组情况。菌株用多位点序列分型基因进行表征，而和则使用16基因。在3509个个体宿主节肢动物中，属于390个形态物种，12.05%感染了，2.82%感染了，2.05%感染了。宿主与内共生菌之间的系统发育不一致表明该群落内共生菌存在广泛的水平转移。还发现了超组之间的三起重组事件和超组内的八起重组事件。相似性统计检验表明，超组A和显示出与群落内广泛水平转移一致的模式，但超组B和则不然。我们强调了广泛的全群落研究对于更好地理解内共生菌在全球节肢动物群落中传播的重要性。
