Meeting Abstract

116.1  Tuesday, Jan. 7 10:15  Host-symbiont dynamics in the Atlantic Forest hotspot SCHWEITZER, A.M.*; PERKINS, S.L.; CARNAVAL, A.C.; The Graduate Center, CUNY; The American Museum of Natural History; The City College of New York amandaschweitzer5@gmail.com

To better understand the effects of long-term climatic changes on spatial patterns of biodiversity, we examine the host-symbiont dynamics of skin bacteria from widely distributed frogs in the Brazilian Atlantic Forest, targeting species used in phylogeographic studies such as Hypsiboas faber, H. semilineatus, and H. albomarginatus. Studies indicate the northern forest lowlands served as large biodiversity refugia to populations of these species during the Last Glacial Maximum while the mostly unsuitable southern lowlands have only been recently recolonized. Phylogeographic data suggests the targeted host species have tracked these changes. We aim to determine if the same historical climatic events have significantly impacted an individual host’s ectosymbiont composition and evaluate whether historical climatic stability can shape contemporary diversity patterns by mediating biotic interactions. To achieve this, we have collected and analyzed bacterial swabs and host DNA samples from breeding ponds across multiple elevations and latitudes in the Atlantic Forest. Collected hosts were swabbed, washed with distilled water to remove transient bacteria, and swabbed again to determine which bacteria have colonized the skin. Swabs were used in DNA cloning and next-generation sequencing to sufficiently sample the microbiome. Symbiont DNA sequence data, generated through conserved 16S primers, are used to test the following hypotheses: i) bacterial alpha diversity is higher in the climatically stable areas and lower in the historically unstable areas; ii) host specificity is higher in areas of stability and lower in areas of instability; iii) symbiont beta diversity is higher in the climatically stable areas and lower in the unstable areas.