Does adaptive radiation of a host lineage promote ecological diversity of its bacterial communities? A test using gut microbiota of Anolis lizards

Abstract

Adaptive radiations provide unique opportunities to test whether and how recent ecological and evolutionary diversification of host species structures the composition of entire bacterial communities. We used 16S rRNA gene sequencing of faecal samples to test for differences in the gut microbiota of six species of Puerto Rican Anolis lizards characterized by the evolution of distinct 'ecomorphs' related to differences in habitat use. We found substantial variation in the composition of the microbiota within each species and ecomorph (trunk-crown, trunk-ground, grass-bush), but no differences in bacterial alpha diversity among species or ecomorphs. Beta diversity analyses revealed subtle but significant differences in bacterial composition related to host phylogeny and species, but these differences were not consistently associated with Anolis ecomorph. Comparison of a trunk-ground species from this clade (A. cristatellus) with a distantly related member of the same ecomorph class (A. sagrei) where the two species have been introduced and are now sympatric in Florida revealed pronounced differences in the alpha diversity and beta diversity of their microbiota despite their ecological similarity. Comparisons of these populations with allopatric conspecifics also revealed geographic differences in bacterial alpha diversity and beta diversity within each species. Finally, we observed high intraindividual variation over time and strong effects of a simplified laboratory diet on the microbiota of A. sagrei. Collectively, our results indicate that bacterial communities are only weakly shaped by the diversification of their lizard hosts due to the strikingly high levels of bacterial diversity and variation observed within Anolis species.

Gut microbiota of a long‐distance migrant demonstrates resistance against environmental microbe incursions

“…Finally, we found only weak shifts in gut microbiota composition within the flock over the nonbreeding season, and individual stints underwent large, seemingly random, fluctuations in their gut microbiota composition and diversity, demonstrating a remarkably changeable microbiota within individuals even during sedentary periods. Such dramatic shifts have also been found in other wild species such as anolis lizards (Ren, Kahrl, Wu, & Cox, ) and baboons (Ren, Grieneisen, Alberts, Archie, & Wu, ), suggesting microbial fluctuations in community composition, potentially in response to short‐term shifts in host diet or physiology, may be the norm in wild animals, independent of being sedentary or migratory. However, our findings suggest these changes are likely to be due to short‐term shifts in diet or physiology, rather than exposure to altered environmental microbiota.…”

Gut microbial ecology of lizards: insights into diversity in the wild, effects of captivity, variation across gut regions and transmission

“…A recent study documented a shift in the gut microbiota of insectivorous Anolis sagrei lizards brought into captivity (Ren et al . ). Our current work builds upon this study by investigating omnivorous and herbivorous lizards and demonstrating that species‐specific bacterial signatures are retained in captivity.…”

Are you what you eat? A highly transient and prey‐influenced gut microbiome in the grey house spider Badumna longinqua

“…Our feeding experiment suggests that diet can affect gut microbiome assembly in the spiders in two drastically different ways, depending on the prey taxon. In the case of Drosophila ‐fed spiders, changing physicochemical conditions in the predator's gut after prey ingestion may have caused microbiome remodelling by environmentally derived taxa (Ren et al, ). We detected a considerable change in microbial community composition and diversity in Drosophila ‐fed spiders.…”

“…As for microbial taxa that appeared in Drosophila‐ fed spiders, but were absent from the Drosophila themselves, these newly appearing microbes must have either been acquired from the environment, or were rare taxa already present in the spiders’ guts that underwent abundance shifts after feeding (Costello, Gordon, Secor, & Knight, ; Ren et al, ). Interestingly, many microbes that were later detected as core OTUs in our feeding experiment were already present in some unfed spiders at low frequencies.…”