三种水螨体内共生菌多样性分析

Diversity Analysis of Symbiotic Bacteria in Three Species of Water Mites

为了解厚水螨Hydrachna(Rhabdohydrachna)crassa、瓦松腺水螨Lebertia(Lebertia)fimbriata和短胸湿螨Hygrobates(Hygrobates)bravisterus 3种水螨体内共生菌组成和多样性,采用16S rDNA高通量测序方法对3种水螨的共生菌群进行比较和分析。3种水螨的测序数据经抽平处理后均获得20 844条序列,分别得到34、39和233个OTU。3种水螨中,H.(H.)bravisterus体内共生菌多样性最高,而H.(R.)crassa优势菌的集中程度最高。3种水螨体内共生菌在门和纲级阶元,丰度最高的均为变形菌门、α-变形菌纲。在目级阶元以下,H.(R.)crassa和L.(L.)fimbriata丰度最高的优势菌为立克次氏体目、立克次氏体科、立克次氏体属;而H.(H.)bravisterus丰度最高的优势菌为根瘤菌目。在体内共生菌的组成和丰度上,H.(R.)crassa和L.(L.)fimbriata相似,H.(H.)bravisterus与前2种存在明显差别。研究表明,3种水螨体内共生菌多样性存在差异,不同的生活环境可能是影响水螨体内共生菌差异的主要原因。

In order to investigate the composition and diversity of symbiotic bacteria in three water mite species,Hydrachna(Rhabdohydrachna) crassa,Lebertia(Lebertia) fimbriata and Hygrobates(Hygrobates)bravisterus,high-throughput 16S rDNA sequencing was employed to compare and analyze the symbiotic bacterial communities in these water mites.Following rarefaction,a total of 20,844 sequences were obtained from the sequencing data of the three water mite species,with 34,39,and 233 operational taxonomic units(OTUs)identified for Hydrachna(Rhabdohydrachna)crassa,Lebertia(Lebertia)fimbriata,and Hygrobates(Hygrobates) bravisterus,respectively.The highest diversity of symbiotic bacteria was observed in H.(H.)bravisterus,while the greatest concentration of dominant bacteria was noted in H.(R.)crassa.At the phylum and class taxonomic levels,the most abundant symbiotic bacteria were found to belong to the phylum Proteobacteria and class Alphaproteobacteria across all three water mites.At lower taxonomic levels,the most abundant dominant bacteria in H.(R.)crassa and L.(L.)fimbriata were identified as belonging to the order Rickettsiales,family Rickettsiaceae,and genus Rickettsia.In contrast,the most abundant dominant bacteria in H.(H.) bravisterus were associated with the order Rhizobiales.Regarding the composition and abundance of symbiotic bacteria,similarities were observed between H.(R.) crassa and L.(L.) fimbriata,and distinct differences were noted in H.(H.) bravisterus compared to the other two species.The study indicates that there are differences in the diversity of symbiotic bacteria among the three species of water mites,and different living enviroments may be the primary cause affecting these differences.