Spatial distribution of microbial communities among colonies and genotypes in nursery-reared Acropora cervicornis

Abstract

Background The architecturally important coral species Acropora cervicornis and A. palmata were historically common in the Caribbean, but have declined precipitously since the early 1980s. Substantial resources are currently being dedicated to coral gardening and the subsequent outplanting of asexually reproduced colonies of Acropora, activities that provide abundant biomass for both restoration efforts and for experimental studies to better understand the ecology of these critically endangered coral species. Methods We characterized the bacterial and archaeal community composition of A. cervicornis corals in a Caribbean nursery to determine the heterogeneity of the microbiome within and among colonies. Samples were taken from three distinct locations (basal branch, intermediate branch, and branch tip) from colonies of three different coral genotypes. Results Overall, microbial community composition was similar among colonies due to high relative abundances of the Rickettsiales genus MD3-55 (Candidatus Aquarickettsia) in nearly all samples. While microbial communities were not different among locations within the same colony, they were significantly different between coral genotypes. These findings suggest that sampling from any one location on a coral host is likely to provide a representative sample of the microbial community for the entire colony. Our results also suggest that subtle differences in microbiome composition may be influenced by the coral host, where different coral genotypes host slightly different microbiomes. Finally, this study provides baseline data for future studies seeking to understand the microbiome of nursery-reared A. cervicornis and its roles in coral health, adaptability, and resilience.

Host-specific epibiomes of distinctAcropora cervicornisgenotypes persist after field transplantation

“…These findings point to MD3-55 as the driving factor distinguishing genotype-specific epibiomes, similar to those signatures reported for A. cervicornis tissue samples (Klinges et al 2020;Miller et al 2020;Baker et al 2021). MD3-55 were previously visualized (Gignoux-Wolfsohn et al 2020), and are known to lack basic metabolic pathways, strongly supporting an intracellular lifestyle (Klinges et al 2019).…”

Phosphate enrichment induces increased dominance of the parasite Aquarickettsia in the coral Acropora cervicornis

“…Numerous studies have demonstrated the surprising dominance of the parasitic genus Aquarickettsia in microbiomes of A. cervicornis , and in particular, of disease-susceptible genets of this species (Shaver et al 2017 , Rosales et al 2019 , Klinges et al 2020 , Baker et al 2021 , Aguirre et al 2022 , Miller et al 2020 , Casas et al 2004 , Gignoux-Wolfsohn et al 2020 ). Results from this study were consistent with previous work, as populations of Aquarickettsia were found to comprise 74.98% of the microbiome in samples of A. cervicornis genotype 50, a disease-susceptible genotype (Muller et al 2018 ).…”

High-resolution spatial and genomic characterization of coral-associated microbial aggregates in the coral Stylophora pistillata

“…Numerous 16S ribosomal RNA (rRNA) amplicon-based studies have reported Endozoicomonas (Gammaproteobacteria)-affiliated taxa as the dominant members of the coral microbiome, with diverse phylotypes associated with individual species and across taxonomically dispersed hosts (11,(17)(18)(19)(20). Endozoicomonas strains have been isolated from corals, and their metabolic potential was inferred from derived genomic studies on the isolates and metagenomes assembled from culture-independent studies, suggesting integrated metabolic links facilitating nutrient acquisition and provision and therefore potentially important roles in host health (14,(21)(22)(23)(24).…”