Exploring the development of wild microbiomes in the Eastern Fence Lizard
This study examines the gut microbiome from fecal samples of a reptilian model (Sceloporus undulatus). Vertebrates display a diverse range of variability in gut microbiota. The dynamic host-symbiote interactions between gut microbiota are essential in various metabolic processes and overall health of the host organism. We used 16S rRNA gene sequencing to profile the bacterial community from the guts of wild Eastern Fence Lizards. Microbiome profiles were collected at four distinct time points when lizards were actively foraging in the environment and across four age groups, aiming to characterize the natural variation in bacterial diversity among wild specimens. Bioinformatic analysis was conducted using QIIME2/DADA2 pipelines. Successional changes in the gut microbiome of lizards from the juvenile stage to adulthood revealed a pattern of increased functionality and diversity. Environmental bacteria such as Mycobacterium and Pantoea in young of year (YOY) lizards underwent successional microbiome changes to taxa including Caproiciproducens, Eubacterium, Fusobacterium, and Roseburia in adults, reflecting dietary shifts from maternal nutrients and early-stage prey to fiber-rich arthropod diets. Juvenile lizards exhibited a simple gut microbiome dominated by pioneer colonizers (Firmicutes, Bacteroidota, and Proteobacteria), with alpha diversity increasing rapidly within a month to near adult-level. This research extends our understanding of reptilian microbiomes, capturing a snapshot of the ecological complexities of Eastern Fence Lizard microbiomes.