高通量测序方法分析两种草食性淡水螺肠道菌群多样性

High-throughput sequencing analysis of intestinal flora diversity of two freshwater snails (Radix auricularia and Planorbella trivolvis)

摘要:

淡水螺是水生态系统中重要的生物类群，也是多种寄生虫的中间宿主。肠道菌群在动物能量代谢和抵抗病原体方面起着重要作用。本文分析了耳萝卜螺Radix auricularia和三旋卷丽螺Planorbella trivolvis肠道菌群的多样性。结果表明：在门水平上，耳萝卜螺有23个菌门，以变形菌门 (Proteobacteria，33.63%)、蓝细菌门(Cyanobateria，15.33%)、绿弯菌门 (Chloroflexi，13.95%) 和放线菌门 (Actinobacteria，12.99%)为主；三旋卷丽螺有13个菌门，以变形菌门 (54.88%)、拟杆菌门 (Bacteroidetes，28.49%) 和放线菌门 (7.65％) 为主。属水平上，耳萝卜螺有厚皮藻属Pleurocapsa、硫网菌属Thiodictyon、纤毛菌属Leptotrichia及类诺卡氏菌属Nocardioides等445个属；三旋卷丽螺有Cloacibacterium、OM60NOR5_clade、假单胞菌属Pseudomonas及红杆菌属Rhodobacter等238个属。有93个菌属为两种螺的共有核心菌群 (所有样本中都存在)，其中27个菌属丰度大于0.5%。两种螺肠道菌群结构差异显著 (P=0.027)。PICRUSt功能预测分析表明，两种螺肠道菌群KEGG功能组成相似，氨基酸代谢、碳水化合物代谢及膜转运丰度较大。综上，两种草食性淡水螺肠道菌群多样性较高且差异显著，但有数量较多的共有核心菌群。

Abstract:

Freshwater snail is an important biological group in aquatic ecosystem and an intermediate host of many parasites. Intestinal flora plays an important role in animal energy metabolism and resistance to pathogens. We analyzed the intestinal microbiota diversity of Radix auricularia (RA) and Planorbella trivolvis (PL) by 16S rRNA high-throughput sequencing. At the phylum level, RA had 23 phyla, including Proteobacteria (33.63%), Cyanobacteria (15.33%), Chloroflexi (13.95%), and Actinomycetes (12.99%). PL had 13 phyla, including Proteobacteria (54.88%), Bacteroidetes (28.49%), and Actinomycetes (7.65%). At the genus level, there were 445 genera in RA, including Pleurocapsa, Thiodictyon, Leptotrichia, and Nocardioides. There were 238 genera in PL, including Cloacibacterium, OM60NOR5_clade, Pseudomonas, and Rhodobacter. Ninety-three genera were the common core flora of the two snail species (all the samples were present), and 27 genera had an abundance greater than 0.5%. The structure of intestinal microbiota was significantly different between the two groups (P=0.027). We performed the functional prediction of intestinal microbiota using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt), and the results show that the KEGG functional composition of the intestinal flora of the two snails was similar, and the abundance of the amino acid metabolism, carbohydrate metabolism and membrane transport were large. In summary, the intestinal microbiota of the two snails was high in diversity and significantly different, but there were a large number of common core flora.