Gut Microbiome Analyses of Wild Migratory Freshwater Fish (Megalobrama terminalis) Through Geographic Isolation

Yaqiu Liu; Yuefei Li; Jie Li; Qiong Zhou; Xinhui Li

doi:10.3389/fmicb.2022.858454

Gut Microbiome Analyses of Wild Migratory Freshwater Fish (Megalobrama terminalis) Through Geographic Isolation

Front Microbiol. 2022 Apr 8:13:858454. doi: 10.3389/fmicb.2022.858454. eCollection 2022.

Authors

Yaqiu Liu^{1

2

3

4}, Yuefei Li^{1

3

4}, Jie Li^{1

3

4}, Qiong Zhou², Xinhui Li^{1

3

4}

Affiliations

¹ Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.
² Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture and Rural Areas, College of Fisheries, Huazhong Agricultural University, Wuhan, China.
³ Guangzhou Scientific Observing and Experimental Station of National Fisheries Resources and Environment, Guangzhou, China.
⁴ Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Chinese Academy of Fishery Sciences, Guangzhou, China.

Abstract

Gut microbiome is considered as a critical role in host digestion and metabolic homeostasis. Nevertheless, the lack of knowledge concerning how the host-associated gut microbiome underpins the host metabolic capability and regulates digestive functions hinders the exploration of gut microbiome variation in diverse geographic population. In the present study, we selected the black Amur bream (Megalobrama terminalis) that inhabits southern China drainage with multiple geographic populations and relatively high digestive plasticity as a candidate to explore the potential effects of genetic variation and environmental discrepancy on fish gut microbiome. Here, high-throughput 16S rRNA gene sequencing was utilized to decipher the distinct composition and diversity of the entire gut microbiota in wild M. terminalis distributed throughout southern China. The results indicated that mainland (MY and XR) populations exhibited a higher alpha diversity than that of the Hainan Island (WS) population. Moreover, a clear taxon shift influenced by water temperature, salinity (SA), and gonadosomatic index (GSI) in the course of seasonal variation was observed in the gut bacterial community. Furthermore, geographic isolation and seasonal variation significantly impacted amino acid, lipid, and carbohydrate metabolism of the fish gut microbiome. Specifically, each geographic population that displayed its own unique regulation pattern of gut microbiome was recognized as a specific digestion strategy to enhance adaptive capability in the resident environment. Consequently, this discovery suggested that long-term geographic isolation leads to variant environmental factors and genotypes, which made a synergetic effect on the diversity of the gut microbiome in wild M. terminalis. In addition, the findings provide effective information for further exploring ecological fitness countermeasures in the fish population.

Keywords: Megalobrama terminalis; degradation enzymes; geographic isolation; gut microbiome; metabolism.