斑头雁成鸟与雏鸟泄殖腔微生物的对比分析

Comparative Analysis of the Cloacal Microbiome of both Adult and Chick Bar-Headed Geese(Anser indicus)

肠道微生物通过维持稳态、辅助消化和促进免疫系统发育等方式维护宿主的健康状态。肠道微生物本身则受到宿主的基因、饮食、年龄和环境等因素的影响。然而,肠道微生物的变化与宿主年龄之间的关系仍有许多未知。本研究分别收集斑头雁(Anser indicus)2只成鸟及3只雏鸟泄殖腔样品,提取肠道微生物总DNA,采用16S rRNA高通量测序的方法,分析并比较两年龄阶段鸟类肠道微生物的菌群结构及组成差异。研究发现,斑头雁雏鸟泄殖腔微生物属于9个门,含量最高的前5个门分别是梭杆菌门(48.29%)、厚壁菌门(22.21%)、变形杆菌门(22.07%)、放线菌门(5.02%)和软壁菌门(1.93%)。成鸟泄殖腔微生物属于17个门,最多的依次是变形菌门(64.69%)、厚壁菌门(23.92%)、蓝细菌(8.48%)、放线菌门(1.43%)和梭杆菌门(0.56%)。在属的水平,斑头雁雏鸟泄殖腔微生物属于18个属,而成鸟含有24个属。成鸟泄殖腔微生物的α多样性显著高于雏鸟(P<0.05,Welch′s t-test)。有186个操作分类单元(OTU)属于成鸟和雏鸟共有,而其他640个OTU和90个OTU则分别隶属于成鸟和雏鸟。雏鸟中67.39%的OTUs是成鸟所具有的。基于OTU的聚类结果与年龄分组一致。本结果对认识鸟类肠道微生物与宿主年龄变化之间的关系有一定的参考价值。

Gastrointestinal bacteria contribute to host health by maintaining homeostasis,increasing digestive efficiency,and facilitating the development of the immune system.Host genetics,diets,ages and environments strongly influence the composition of the gut microbiota.However,changes in microbial community structure with host age remain poorly understood.In this study,collected 2 adults and 3 chicks Bar-headed Geese（Anser indicus） cloacal samples,extract total DNA samples,and using 16 S r RNA high-throughput sequencing,analysis and comparison the difference of composition and flora structure.According to analysis the intestinal microflora of adult and chick of bar-headed geese,to observed the dynamic changes of different age stage of bird intestinal microflora.A total of 9 different bacterial phyla were identified in the cloacal microbiota of chicks（Fig.1 a）.The results showed that Fusobacteria predominated（48.29%） among chicks followed by Firmicutes（22.21%）,Proteobacteria（22.07%）,Actinobacteria（5.02%） and Tenericutes（1.93%）（Table 2）.A total of 17 different bacterial phyla were identified in the cloacal microbiota of adults（Fig.1 a）.The top 5 most abundant phyla identified were：Proteobacteria（64.69%）,Firmicutes（23.92%）,Cyanobacteria（8.48%）,Actinobacteria（1.43%） and Fusobacteria（0.56%）（Table 2）.At the genus level,the sequences from the samples represented 18 and 24 genera in chicks and adults,respectively（Fig.1 b）.We employed Chao1 index and observed species curve to estimate the alpha diversity of the chicks and adults cloacal samples.These results suggested that the diversity of the cloacal microbiota of adult bar-headed geese was higher than in chicks.Analyses based on Bray-Curtis distances revealed strong clustering of the samples by age（Fig.3 a）.At the OTU level,there were 186 OTUs shared between the samples from adults and chicks,whereas the other 640 OTUs and 90 OTUs,were specific to the adults and chicks,respectively（Fig.3 b）.These results indicated that majority of OTUs（67.39%） presented in the chicks were also presented in the adults.The top 25 most abundant OTUs at the genus level shared by both adults and chicks were shown in Fig.4.This preliminary study would be valuable for future investigations of the sequential changes in gut microbiota composition with age in birds.