猎豹(Acinonyx jubatus)肠道微生物多样性及其性别差异研究

Diversity and sex-specific differences in the intestinal microbiota of cheetah (Acinonyx jubatus)

摘要:

[目的]探讨猎豹（Acinonyx jubatus）肠道微生物多样性特征。[方法]通过采集新鲜粪便样品，对9只健康成年野生猎豹（4只雄性，5只雌性）的肠道微生物16S rRNA基因V3-V4区进行高通量测序，对猎豹肠道微生物多样性进行研究。[结果]测序共获得肠道微生物16S rRNA基因V3-V4区有效序列599349条，序列平均长度405 bp。通过以97%的序列相似性进行分类，共获得操作分类单元（OTU） 268个。经序列比对和分类鉴定，这些OTU都属于细菌域，包括10个门，21个纲，35个目，72个科，144个属。其中，丰度最高的5个细菌门是厚壁菌门（Firmicutes，平均占OTU总数的42.29%%）、放线菌门（Actinobacteria，31.54%）、梭杆菌门（Fusobacteroidetes，16.66%）、变形菌门（Proteobacteria，5.30%）和拟杆菌门（Bacteroidetes，4.19%）。拟杆菌门的丰度较低是猎豹肠道微生物的主要特征。丰度最高的5个科依次是红蝽杆菌科（Coriobacteriaceae，31.28%）、消化链球菌科（Peptostreptococcaceae，平均占17.66%），梭杆菌科（Fusobacteriaceae，15.46%）、毛螺菌科（Lachnospiraceae，12.40%）、梭菌科I（Clostridiaceae_I，6.93%）等。丰度最高的5个属依次是柯林斯氏菌属（Collinsella，30.16%）、梭杆菌属（Fusobacterium，15.46%）、艰难梭菌属（Peptoclostridium，11.46%）、Blautia属（8.28%）和狭窄梭菌属1（Clostridium_sensu_stricto_1，6.39%）。约有2.32%的OTU没有归类到属。群落alpha多样性分析结果显示，猎豹肠道微生物群落Shannon指数为2.93-4.41，Simpson指数为0.72-0.91。通过依据性别进行分组，对雌雄两组之间的alpha多样性比较表明，雄性组的物种和Shannon指数略高于雌性组。Beta多样性分析表明，雌雄两组之间的差异高于各组内部不同个体之间的差异。然而，聚类分析显示，相同性别的猎豹的肠道微生物并没有聚在一起。[结论]本文通过高通量测序技术研究了猎豹肠道微生物多样性特征和性别差异，为猎豹的保护、救护饲养和消化生理学研究提供了基础数据。

Abstract:

[Objective] This study aimed to investigate the diversity and sex-specific differences in the intestinal microbiota of cheetah (Acinonyx jubatus). [Methods] Fecal samples were collected from 9 healthy adult cheetahs (4 male and 5 female), and intestinal microbiota were assessed through high-throughput sequencing of the V3-V4 region of 16S rRNA gene. [Results] In total, 599349 effective tags were obtained, with an average length of 405 bp. At 97% sequence similarity, 268 operational classification units (OTUs) were obtained and classified into the bacterial domain, including 10 phyla, 21 classes, 35 orders, 72 families, and 144 genera. Based on relative abundance, the 5 most abundant bacterial phyla were Firmicutes (accounting for approximately 42.29% of the total OTUs), Actinobacteria (31.54%), Fusobacteria (16.66%), Proteobacteria (5.30%), and Bacteroidetes (4.19%). The low abundance of phylum Bacteroidetes was the primary feature of the intestinal microbial community of the cheetah. The 5 most abundant families were Coriobacteriaceae (31.28%), Peptostreptococcaceae (17.66%), Fusobacteriaceae (15.46%), Lachnospiraceae (12.40%), and Clostridiaceae_1 (6.93%). The 5 most abundant genera were Collinsella (30.16%), Fusobacterium (15.46%), Peptoclostridium (11.46%), Blautia (8.28%), and Clostridium_sensu_stricto_1 (6.39%). Approximately 2.32% of the total OTUs were unclassified strains at the genus level. Alpha diversity analysis indicated that the Shannon indices of the intestinal microbiota ranged 2.93-4.41; Simpson indices, 0.72-0.91. The observed species and Shannon indices of the intestinal microbiota of male cheetahs were slightly greater than those of female cheetah. Beta diversity analysis revealed that the difference between sexes was greater than that within groups. However, cluster analysis revealed that intestinal microbes of cheetahs of the same sex were not clustered. [Conclusion] The present results show the intestinal microbial diversity of cheetah, and indicate that intestinal microbiota of cheetah do not differ significantly on the basis of sex, thus providing a scientific basis for studies on the conservation of cheetahs and their digestive physiology and for rescuing and feeding cheetahs.