Changes in the gut microbial community of the eastern newt (Notophthalmus viridescens) across its three distinct life stages

Abstract

Understanding the forces that shape vertebrate gut microbial community assembly and composition throughout development is a major focus of the microbiome field. Here, we utilize the complex life cycle of the eastern newt (Notophthalmus viridescens) as a natural wild model to compare the effects of host and environmental factors on gut microbiome development. We compared bacterial inventories of each of the newt's three physiologically distinct developmental stages to determine if each hosted a unique community, or if the two stages which share an aquatic habitat (larvae and adults) harbored more similar communities than those of the third stage, the terrestrial juvenile eft. Additionally, we assessed how the contribution of selective processes to gut microbial assembly changed through development. We found that structurally, each life stage harbored a distinct community, which may be attributable to host factors. Further, across development, we found that community assembly processes shifted from a predominance of neutral to selective forces. However, habitat may also be important in determining community membership and diversity due the uniqueness of eft communities based on these metrics. Our results are similar to those in other vertebrate taxa, suggesting that gut microbiota assembly processes may be conserved across diverse lineages.

Experimental depletion of gut microbiota diversity reduces host thermal tolerance and fitness under heat stress in a vertebrate ectotherm

“…Our results are consistent with other studies finding relative stability in microbial communities of pond water stored at 4°C in the laboratory 39 . In tadpole gut bacterial communities, the dominant phyla overall were Firmicutes and Proteobacteria (Supplementary Figure 2), which appear to be common commensals of larval amphibians, having been documented in high abundance in the guts of several other tadpole species 40, 41 , as well as in the early life-stages of the eastern newt 42 .…”

Heat stress and amphibian immunity in a time of climate change

“…The microbial communities that inhabit the gut and skin of larval amphibians are different from those of adults of the same species [ 83 , 84 ]. Elevated temperatures can alter those communities at the larval stages.…”

Comparison of hypoxia- and hyperoxia-induced alteration of epigene expression pattern in lungs of Pleurodeles waltl and Mus musculus

“…Another interesting property of newts is resistance to carcinogenesis [ 20 , 21 ]. As they are semiaquatic animals, their life cycle follows three developmental stages, such as larvae (aquatic) stage, juvenile (terrestrial) stage, and adult (semiaquatic) stage [ 22 ]. Similar to having different developmental phases and habitats, they have different ways of breathing.…”