Lipopolysaccharide treatment stimulates Pocillopora coral genotype-specific immune responses but does not alter coral-associated bacteria communities

• Published in: Developmental and comparative immunology Vol. 109; p. 103717
• Main Authors: Connelly, Michael T., McRae, Crystal J., Liu, Pi-Jen, Traylor-Knowles, Nikki
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.08.2020; Elsevier Science Ltd
• Subjects: animal pathogens; Bacteria; bacterial communities; Coral; Corals; diagnostic techniques; Gene expression; gene expression regulation; genome; Genomes; genotype; Genotype & phenotype; Genotypes; host-pathogen relationships; Immune response; Immune system; immunologic receptors; Innate immunity; Lipopolysaccharide; Lipopolysaccharides; Microbiome; Microorganisms; Pocillopora; Pocillopora damicornis; Pore formation; Ribonucleic acid; RNA; sequence analysis; Symbiosis; Taiwan; Toxins; Transcription factors; Taiwan; Lipopolysaccharide; Innate immunity; Bacteria; Coral; Microbiome
• ISSN: 0145-305X; 1879-0089; 1879-0089
• DOI: 10.1016/j.dci.2020.103717

Corals are comprised of a coral host and associated microbes whose interactions are mediated by the coral innate immune system. The diversity of immune factors identified in the Pocillopora damicornis genome suggests that immunity is linked to maintaining microbial symbioses while also being able to detect pathogens. However, it is unclear which immune factors respond to specific microbe-associated molecular patterns and how these immune reactions simultaneously affect coral-associated bacteria. To investigate this, fragments of P. damicornis and P. acuta colonies from Taiwan were subjected to lipopolysaccharide (LPS) treatment to stimulate immune responses and measure bacteria community shifts. RNA-seq revealed genotype-specific immune responses to LPS involving the upregulation of immune receptors, transcription factors, and pore-forming toxins. Bacteria 16S sequencing revealed significantly different bacteria communities between coral genotypes but no differences in bacteria communities were caused by LPS. Our findings confirm that Pocillopora corals activate conserved immune factors in response to LPS and identify transcription factors coordinating Pocillopora corals’ immune responses. Additionally, the strong effect of coral genotype on gene expression and bacteria communities highlights the importance of coral genotype in the investigation of coral host-microbe interactions. •Pocillopora coral immune factors were upregulated after LPS treatment.•Coral bacteria community compositions did not shift after LPS treatment.•Coral gene expression and bacteria communities showed strong genotypic effects.•Only six transcripts were upregulated in every coral genotypes' response to LPS.•Immunity-bacteria interactions may be critical for understanding coral resilience.