Heitlinger Emanuel, Ferreira Susana C M, Thierer Dagmar, Hofer Heribert, East Marion L
Research Group Ecology and Evolution of Molecular Parasite Host Interactions, Leibniz Institute for Zoo and Wildlife ResearchBerlin, Germany.
Institute for Biology, Molecular Parasitology, Humboldt UniversityBerlin, Germany.
Front Cell Infect Microbiol. 2017 Jun 16;7:262. doi: 10.3389/fcimb.2017.00262. eCollection 2017.
In mammals, two factors likely to affect the diversity and composition of intestinal bacteria (bacterial microbiome) and eukaryotes (eukaryome) are social status and age. In species in which social status determines access to resources, socially dominant animals maintain better immune processes and health status than subordinates. As high species diversity is an index of ecosystem health, the intestinal biome of healthier, socially dominant animals should be more diverse than those of subordinates. Gradual colonization of the juvenile intestine after birth predicts lower intestinal biome diversity in juveniles than adults. We tested these predictions on the effect of: (1) age (juvenile/adult) and (2) social status (low/high) on bacterial microbiome and eukaryome diversity and composition in the spotted hyena (), a highly social, female-dominated carnivore in which social status determines access to resources. We comprehensively screened feces from 35 individually known adult females and 7 juveniles in the Serengeti ecosystem for bacteria and eukaryotes, using a set of 48 different amplicons (4 for bacterial 16S, 44 for eukaryote 18S) in a multi-amplicon sequencing approach. We compared sequence abundances to classical coprological egg or oocyst counts. For all parasite taxa detected in more than six samples, the number of sequence reads significantly predicted the number of eggs or oocysts counted, underscoring the value of an amplicon sequencing approach for quantitative measurements of parasite load. In line with our predictions, our results revealed a significantly less diverse microbiome in juveniles than adults and a significantly higher diversity of eukaryotes in high-ranking than low-ranking animals. We propose that free-ranging wildlife can provide an intriguing model system to assess the adaptive value of intestinal biome diversity for both bacteria and eukaryotes.
在哺乳动物中，可能影响肠道细菌（细菌微生物组）和真核生物（真核生物组）多样性及组成的两个因素是社会地位和年龄。在社会地位决定资源获取的物种中，处于社会优势地位的动物比处于从属地位的动物维持着更好的免疫过程和健康状况。由于高物种多样性是生态系统健康的一个指标，因此更健康、处于社会优势地位的动物的肠道生物群落应该比从属动物的更具多样性。出生后幼年期肠道的逐渐定殖预示着幼年期的肠道生物群落多样性低于成年期。我们针对以下影响进行了验证：（1）年龄（幼年/成年）和（2）社会地位（低/高）对斑鬣狗肠道细菌微生物组和真核生物组的多样性及组成的影响。斑鬣狗是一种高度群居、以雌性为主导的食肉动物，其社会地位决定资源获取。我们采用多扩增子测序方法，使用一组48种不同的扩增子（4种用于细菌16S，44种用于真核生物18S），对塞伦盖蒂生态系统中35只已知个体的成年雌性斑鬣狗和7只幼年斑鬣狗的粪便进行了细菌和真核生物的全面筛查。我们将序列丰度与传统的粪便虫卵或卵囊计数进行了比较。对于在六个以上样本中检测到的所有寄生虫分类群，序列读数的数量显著预测了所计数的虫卵或卵囊的数量，这突出了扩增子测序方法在定量测量寄生虫负荷方面的价值。与我们的预测一致，我们的结果显示，幼年斑鬣狗的微生物组多样性明显低于成年斑鬣狗，而高等级动物的真核生物多样性明显高于低等级动物。我们提出，自由放养的野生动物可以提供一个有趣的模型系统，以评估肠道生物群落多样性对细菌和真核生物的适应性价值。
