Fecal Bacterial Community of Allopatric Przewalski's Gazelles and Their Sympatric Relatives.

Ruoshuang Liu,Jianbin Shi,Susanne Shultz,Dongsheng Guo,Dingzhen Liu

doi:10.3389/fmicb.2021.737042

Abstract

Mammal gastrointestinal tracts harbor diverse bacterial communities that play important roles in digestion, development, behavior, and immune function. Although, there is an increasing understanding of the factors that affect microbial community composition in laboratory populations, the impact of environment and host community composition on microbiomes in wild populations is less understood. Given that the composition of bacterial communities can be shaped by ecological factors, particularly exposure to the microbiome of other individuals, inter-specific interactions should impact on microbiome community composition. Here, we evaluated inter-population and inter-specific similarity in the fecal microbiota of Przewalski’s gazelle (Procapra przewalskii), an endangered endemic ruminant around Qinghai Lake in China. We compared the fecal bacterial communities of three Przewalski’s gazelle populations, with those of two sympatric ruminants, Tibetan gazelle (Procapra picticaudata) and Tibetan sheep (Ovis aries). The fecal bacterial community richness (Chao1, ACE) did not vary across the three Przewalski’s gazelle populations, nor did the composition vary between species. In contrast, the managed Przewalski’s gazelle population had higher bacterial diversity (Shannon and Simpson) and was more similar to its sympatric Tibetan sheep in beta diversity than the wild Przewalski’s gazelle populations. These results suggest that ecological factors like host community composition or diet affect Przewalski’s gazelle’s gastrointestinal bacterial community. The role of bacterial community composition in maintaining gastrointestinal health should be assessed to improve conservation management of endangered Przewalski’s gazelle. More broadly, captive breeding and reintroduction efforts may be impeded, where captive management results in dysbiosis and introduction of pathogenic bacteria. In free ranging populations, where wildlife and livestock co-occur, infection by domestic pathogens and diseases may be an underappreciated threat to wild animals.

Highlights

Animals harbor microorganism communities in a number of habitats (West et al, 2019) that play key roles in host biology (Mueller and Sachs, 2015; Sun et al, 2018)
The predominant phyla in all five populations of the three species were Firmicutes (37.27–72.82%) and Bacteroidetes (5.85–44.57%), followed by seven other phyla that represented more than 0.01% of the total sequences in every sample, including Actinobacteria (0.02–41.46%), Verrucomicrobia (0.02–19.29%), Proteobacteria (0.13–10.92%), Tenericutes (0.11–2.50%), Cyanobacteria (0.04– 2.62%), Spirochaetae (0.02–7.12%), and Saccharibacteria (0.05– 1.67%; Table 2)
Combining the results from intra-species comparison of Przewalski’s gazelles, we found that the fecal bacterial community of Przewalski’s gazelles at Bird Island (PG-B) shifted to resemble that of sympatric Tibetan sheep (TS-B): several bacterial genera such as Desulfovibrio, Spirochete, and Clostridium did not exist in their wild relatives (PG-S or Przewalski’s gazelles from Haergai River (PG-H))

Summary

Introduction

Animals harbor microorganism communities in a number of habitats (West et al, 2019) that play key roles in host biology (Mueller and Sachs, 2015; Sun et al, 2018). The mammalian gastrointestinal microbiome is dominated by Firmicutes and Bacteroidetes, which contain many anaerobic fermentative bacterial species These bacteria digest and ferment plant structural carbohydrates into available products like shortchain fatty acids (SCFAs, predominantly acetate, butyrate, and propionate), which are absorbed by the host (Amato et al, 2016; Lan and Yang, 2019; Sun et al, 2020). Herbivores and ruminants depend on the microbial fermentation products and other metabolites such as vitamins and highquality proteins for more than two-thirds of their daily energetic requirements (Morgavi et al, 2013; Furman et al, 2020) This long-time co-evolved holobiont (the host and its symbiotic microbiota) has adaptive plasticity to external environments. This convergent adaption of yaks and Tibetan sheep increases their feeding efficiency to cope with a harsh highaltitude environment (Zhang et al, 2016)

Methods

Results

Conclusion