Seasonal shifts in the insect gut microbiome are concurrent with changes in cold tolerance and immunity

1. Seasonal changes in the environment, such as varying temperature, have the potential to change the functional relationship between ectothermic animals, such as insects, and their microbiomes. Our objectives were to determine: a) whether seasonal changes in temperature shift the composition of the insect gut microbiome, and b) if changes in the microbiome are concomitant with changes in the physiology of the host, including the immune system and response to cold. 2. We exposed laboratory populations of the spring field cricket, Gryllus veletis (Orthoptera: Gryllidae), to simulated overwintering winter and spring, we extracted and sequenced 16S bacterial genomic DNA from cricket guts, to capture seasonal variation in the composition of the microbiome. 3. The composition of the gut microbiome was similar between microcosms, and overall me, where overwintering resulted in permanent changes to these microbial communities. In particular, the abundance of Pseudomonas spp. decreased, and tha...