Factores ecológicos y evolutivos que modulan las comunidades bacterianas del intestino en diferentes especies de lagartijas del genero Sceloporus.

Abstract

The gut microbiota comprises a complex microbial community influenced by a diverse range of extrinsic and intrinsic factors. In vertebrate hosts, the major richness and abundance of microbial taxa resides in the gastrointestinal tract (GIT), which exerts a central role in nutrient absorption, intestinal homeostasis, immune system, protection against pathogens, hormone and vitamin production, among others. However, to date, most microbial studies have been performed on human and laboratory animals and little is known about the gut microbiota composition in wild populations, particularly in reptilian species, one of the most diverse and successful groups of vertebrates. Therefore, understanding how the gut microbiota contributes to host fitness is a major goal of microbial research. Moreover, to avoid lethal procedures in wild populations is necessary to estimate which non-lethal method (fecal samples or cloacal swabs) is more accurate to assess GIT microbiota. Here, through next-generation sequencing technology, we examined the variation of gut bacterial communities among four lizard species of the genus Sceloporus (S. aeneus, S. bicanthalis, S. grammicus and S. spinosus) inhabiting a mountainous region in central Mexico (La Malinche volcano). The bacterial 16S rRNA gene was PCR-amplified to assess the gut bacterial communities and investigate how environmental conditions, phylogenetic relatedness, seasonal dynamics and diet composition influence their diversity and composition. Furthermore, by amplifying the mitochondrial cytochrome c oxidase subunit I (COI) gene, we characterized the diet of these Sceloporus lizard species during the dry and rainy seasons and explored whether seasonal dietary changes promote seasonal variation in gut microbiota composition.