Comparison of Porifera Bacterial Symbiont Community Profiles Based on Species and Source Template

Comparison of Porifera Bacterial Symbiont Community Profiles Based on Species and Source Template

Sponges exhibit complex, species-specific microbial symbioses. The role of symbiont communities, known as “microbiomes”, to create a “holobiont” with their host is not fully understood. Microbiomes can be characterized by sequencing 16S rRNA fragments from total community genomic DNA (gDNA). The purpose of this study is to sequence bacterial rRNA from previously isolated cDNA (complementary DNA synthesized from RNA samples) and compare the profiles to gDNA. The samples were derived from the Porifera Tree of Life (PorTol.org). I hypothesize that microbial profiles derived from gDNA templates will be nearly identical to those found in cDNA of the same sponge species. We assume that cDNA sequences represent active and viable bacteria that can be compared with microbial profiles of gDNA templates (which may hold inactive, or less viable microbes). Samples were PCR amplified using universal 515/806 primers which have been applied in the EarthMicrobiomeProject.org. The PCR products were then analyzed using gel electrophoresis to confirm the presence of bacterial genes (specifically 16S rRNA, a nuclear housekeeping gene). Next, the samples were purified and run on a genome sequencer (Illumina MiSeq) to acquire variable region V4 sequences of active bacterial communities present in the sponge cDNA and DNA samples. The next step for this research will be to analyze the raw microbiome data using R-based statistical software and QIIME. Bacterial community identities present in each sample will be compared across sponge species and group in order to determine the levels of relatedness, as well as compare differences between cDNA and DNA results.