巴里坤卤虫不同发育时期肠道菌群结构分析

Analysis on composition of intestinal microbiota of Artemia parthenogenetica at different growth stages

采用Illumina MiSep高通量测序技术,比较室内养殖条件下巴里坤卤虫(Artemia parthenogenetica)在无节幼虫期(S1)、后无节幼虫期(S2)、拟成虫期(S3)和成虫期(S4)的肠道菌群结构特征。结果显示:1)在门水平上,变形菌门和厚壁菌门为各发育时期优势菌群,拟杆菌门和放线菌门相对丰度随发育进行逐渐增加。2)在纲水平上,无节幼虫期优势菌群为α-变形菌纲,而后无节幼虫期、拟成虫期和成虫期为γ-变形菌纲。3)在属水平上,假单胞菌属相对丰度随发育进行呈递增趋势,而微小杆菌属相对丰度处于波动状态。结果表明,巴里坤卤虫不同发育时期的肠道菌群结构存在明显差异。

The assembly of intestine microbial communities is a vital event in animal development,and the resulting associations between animals and intestinal microbiota profoundly influence the maturation of their tissues and the function of adult organs.Artemia is a small branchiopod crustacean found almost worldwide in natural saline lakes and solar salt works.They are used worldwide as live feed in aquaculture production.It has also been used as a model organism for host-microbial studies among others.During the host development,different shifts happen in intestinal microbiota depending on host age.However,the extent to which this process mirrors the developmental programs of host tissues is unknown.In an effort to better understand the relationship between intestinal microbiota and Artemia,it is necessary to identify the composition of the microbiota and understand how they vary during Artemia development.In the present study,we collected samples at four stages of Artemia parthenogenetica from Barkol:the nauplius stage(S1,24 h),the metanauplius stage(S2,48 h),the pseudo adult stage(S3,144 h)and the adult stage(S4,264 h)and documented the changes in the intestine bacterial community using Illumina MiSep high throughput sequencing.These samples were obtained by indoors culture systems.All stages were carried out in triplicate.The operational taxonomic unit(OTU)was assigned at 97%sequence identity.The results showed that a total of 2 105 OTUs were obtained from intestinal microbiota.The intestine bacterial community was dominated by two bacterial phyla,proteobacteria and firmicutes at all stages,bacteroidetes and actinobacteria relative abundance gradually increased.Meanwhile,at the level of class classification,bacterial members belonging to alphaproteobacteria dominated in the intestine bacterial community during the nauplius stages of A.parthenogenetica,which was the gammaproteobacteria in other developmental stages.In addition,at the level of genus classification,the relative abundance of Pseudomonas increased rapidly,whereas the relative abundance of Microbacterium was in a fluctuating state.Our results indicated that the structure of intestine bacterial is obviously different at different developmental stages of A.parthenogenetica.A.parthenogenetica intestinal microbiota assemble into distinct communities throughout development.