Differences in Gut Microbiome Composition Between Sympatric Wild and Allopatric Laboratory Populations of Omnivorous Cockroaches

Abstract

Gut microbiome composition is determined by a complex interplay of host genetics, founder’s effects, and host environment. We are using omnivorous cockroaches as a model to disentangle the relative contribution of these factors. Cockroaches are a useful model for host–gut microbiome interactions due to their rich hindgut microbial community, omnivorous diet, and gregarious lifestyle. In this study, we used 16S rRNA sequencing to compare the gut microbial community of allopatric laboratory populations of Periplaneta americana as well as sympatric, wild-caught populations of P. americana and Periplaneta fuliginosa, before and after a 14 day period of acclimatization to a common laboratory environment. Our results showed that the gut microbiome of cockroaches differed by both species and rearing environment. The gut microbiome from the sympatric population of wild-captured cockroaches showed strong separation based on host species. Laboratory-reared and wild-captured cockroaches from the same species also exhibited distinct gut microbiome profiles. Each group of cockroaches had a unique signature of differentially abundant uncharacterized taxa still present after laboratory cultivation. Transition to the laboratory environment resulted in decreased microbiome diversity for both species of wild-caught insects. Interestingly, although laboratory cultivation resulted in similar losses of microbial diversity for both species, it did not cause the gut microbiome of those species to become substantially more similar. These results demonstrate how competing factors impact the gut microbiome and highlight the need for a greater understanding of host–microbiome interactions.

Of Cockroaches and Symbionts: Recent Advances in the Characterization of the Relationship between Blattella germanica and Its Dual Symbiotic System

“…On the one hand, the host's species play a key role in shaping it. In omnivorous gregarious cockroaches, there is a strong association between host species and gut microbiota composition, and even a weak but significant correlation between host family and gut microbiota [52], while different species living in sympatry have a species-dependent composition [60]. On the other hand, insects from the same species living in different environments host different bacterial communities in their guts [20,55].…”

“…On the other hand, insects from the same species living in different environments host different bacterial communities in their guts [20,55]. Thus, the composition is more diverse in wild cockroaches than in lab-reared ones [60,65,87], a change that appears to be associated with their omnivorous diet, which can be highly variable for wild roaches.…”

Transcriptome Responses to Defined Insecticide Selection Pressures in the German Cockroach (Blattella germanica L.)

“…However, there appears to be wider variation with respect to disappearance of microbial contigs (right side of Figure 6A). This finding is logical given that different environments have different microbiomes associated with them that can, in turn, shape internal microbiomes of higher organisms living within them (Renelies-Hamilton et al, 2021;Tinker and Ottesen, 2021).…”

Cockroaches: a potential source of novel bioactive molecule(s) for the benefit of human health

“…Cockroaches are a fascinating and ancient species, and are hemimetabolous insects of the class Insecta , order Blattodea , which also includes termites, with their ancestors originating from the Carboniferous period, emerging approximately 300–350 million years ago (Tinker and Ottesen 2021 ; Wang et al 2017 ; Zhao et al 2017 ). To date, around 4700 species of cockroaches are known; however, it is speculated that at least twice this number is yet to be ascertained (Beccaloni 2014 ).…”