大银鱼早期发育阶段微生物群落特征及其与免疫和代谢的关联

Characteristics of microbial communities and their association with immunity and metabolism at the early developmental stage of Protosalanx chinensis

为了解大银鱼早期发育过程中的微生物群落变化规律与特征,采集大银鱼胚胎期(心跳期,XT)、内源性营养期(采样时间为孵化后第1天,记为H1)、混合性营养期(孵化后第4天,H4)、开口摄食期(孵化后第7天,H7)和外源性营养期(孵化后第10天,H10)5个发育时期的样本。通过16S rRNA基因测序技术观察大银鱼早期发育过程中的微生物群落演替,尤其是摄食前后的微生物群落特征和关键菌属;并结合同批次样品的转录组数据,基于关联网络方法重点分析了与免疫和代谢相关的菌属。结果显示:大银鱼早期发育阶段各时期的β多样性存在显著差异(P<0.001),其中,XT的优势菌群为黄杆菌属(Flavobacterium)和金黄杆菌属(Chryseobacterium);胚后H1时期的优势菌群为假单胞菌属(Pseudomonas);H4时期的主要菌群为黄杆菌属和假单胞菌属;H7和H10时期的主要菌群为弯曲杆菌属(Flectobacillus)和假单胞菌属。假单胞菌属在各时期中稳定存在。与多种免疫和代谢基因表达显著相关的是弯曲杆菌属等节点菌属。本研究首次获得了大银鱼早期发育阶段的微生物演替信息,同时,筛选到的优势菌属与节点菌属将为大银鱼苗种的规模化培育提供思路和参考。

In order to understand the changes and characteristics of microbial communities during early development of Protosalanx chinensis,samples were collected at five developmental periods,which are the embryonic period(heartbeat stage,XT),the endogenous nutrition period(the first day after hatching,H1),the mixed nutrition period(the fourth day after hatching,H4),the open feeding period(the seventh day after hatching,H7),and the exogenous nutrition period(the tenth day after hatching,H10).Microbial community succession during early development was observed by 16S rRNA gene sequencing technology,especially the characteristics and key microbial genera before and after feeding.Combined with the transcriptome data of the same batch of samples,the microbial genera related to immunity and metabolism were analyzed based on the association network method.The results showed that there were significant differences inβdiversity among the different periods at the early developmental stage(P<0.001).The dominant bacteria in the XT period were Flavobacterium and Chryseobacterium,and the dominant bacterium in the H1 period was Pseudomonas.The main bacteria in the H4 period were Flavobacterium and Pseudomonas.The main bacteria in H7 and H10 periods were Flectobacillus and Pseudomonas.The abundance of Pseudomonas was stable at all developmental periods.Node bacteria such as Flectobacillus were significantly associated with the expression of various immune and metabolic genes.This study has obtained the microbial succession information of the early developmental stage of P.chinensis for the first time,and screened out the dominant bacteria and node bacteria,which will provide references and ideas for the scaled cultivation of P.chinensis fry.