No impact of a short-term climatic “El Niño” fluctuation on gut microbial diversity in populations of the Galápagos marine iguana (Amblyrhynchus cristatus)
Open Access
- 2 February 2021
- journal article
- research article
- Published by Springer Science and Business Media LLC in The Science of Nature
- Vol. 108 (1), 1-15
- https://doi.org/10.1007/s00114-020-01714-w
Abstract
Gut microorganisms are crucial for many biological functions playing a pivotal role in the host’s well-being. We studied gut bacterial community structure of marine iguana populations across the Galápagos archipelago. Marine iguanas depend heavily on their specialized gut microbiome for the digestion of dietary algae, a resource whose growth was strongly reduced by severe “El Niño”-related climatic fluctuations in 2015/2016. As a consequence, marine iguana populations showed signs of starvation as expressed by a poor body condition. Body condition indices (BCI) varied between island populations indicating that food resources (i.e., algae) are affected differently across the archipelago during ‘El Niño’ events. Though this event impacted food availability for marine iguanas, we found that reductions in body condition due to “El Niño”-related starvation did not result in differences in bacterial gut community structure. Species richness of gut microorganisms was instead correlated with levels of neutral genetic diversity in the distinct host populations. Our data suggest that marine iguana populations with a higher level of gene diversity and allelic richness may harbor a more diverse gut microbiome than those populations with lower genetic diversity. Since low values of these diversity parameters usually correlate with small census and effective population sizes, we use our results to propose a novel hypothesis according to which small and genetically less diverse host populations might be characterized by less diverse microbiomes. Whether such genetically depauperate populations may experience additional threats from reduced dietary flexibility due to a limited intestinal microbiome is currently unclear and calls for further investigation.Keywords
Funding Information
- Alexander von Humboldt-Stiftung
- Swiss Friends of the Galápagos Islands
This publication has 70 references indexed in Scilit:
- A ntimicrobial peptides and gut microbiota in homeostasis and pathologyEMBO Molecular Medicine, 2013
- Phylogenetic analysis of the fecal microbial community in herbivorous land and marine iguanas of the Galápagos Islands using 16S rRNA-based pyrosequencingThe ISME Journal, 2011
- Individuality in gut microbiota composition is a complex polygenic trait shaped by multiple environmental and host genetic factorsProceedings of the National Academy of Sciences of the United States of America, 2010
- QIIME allows analysis of high-throughput community sequencing dataNature Methods, 2010
- Regulation of inflammatory responses by gut microbiota and chemoattractant receptor GPR43Nature, 2009
- Diet-Induced Obesity Is Linked to Marked but Reversible Alterations in the Mouse Distal Gut MicrobiomeCell Host & Microbe, 2008
- adegenet: a R package for the multivariate analysis of genetic markersBioinformatics, 2008
- Human gut microbes associated with obesityNature, 2006
- Corticosterone levels predict survival probabilities of Galápagos marine iguanas during El Niño eventsProceedings of the National Academy of Sciences of the United States of America, 2001
- Phylogenies and the Comparative MethodThe American Naturalist, 1985