RT Journal Article SR Electronic T1 Characterization of coral-associated microbial aggregates (CAMAs) within tissues of the coral Acropora hyacinthus JF bioRxiv FD Cold Spring Harbor Laboratory SP 576488 DO 10.1101/576488 A1 Naohisa Wada A1 Mizuki Ishimochi A1 Taeko Matsui A1 F. Joseph Pollock A1 Sen-Lin Tang A1 Tracy D. Ainsworth A1 Bette L. Willis A1 Nobuhiro Mano A1 David G. Bourne YR 2019 UL http://biorxiv.org/content/early/2019/03/23/576488.abstract AB Bacterial diversity associated with corals has been studied extensively, however, localization of bacterial associations within the holobiont is still poorly resolved. Here we provide novel insight into the localization of coral-associated microbial aggregates (CAMAs) within tissues of the coral Acropora hyacinthus using histological and fluorescent in situ hybridization approaches. In total, 318 CAMAs were characterized and shown to be distributed extensively throughout coral tissues collected from five sites in Japan and Australia. Density of basophilic CAMAs was typically higher at inshore sites (20.13 per cm2 at inshore sites in Okinawa, Japan; 5.43 per cm2 at inner shelf sites in the northern Great Barrier Reef) than at offshore sites on the GBR (0 to 1.1 per cm2). CAMAs were randomly distributed across the six coral tissue regions investigated. Within each CAMA, bacterial cells had similar morphological characteristics, but bacterial morphologies varied among CAMAs, with at least five distinct types identified. Identifying the location of microorganisms associated with the coral host is a prerequisite for understanding their contributions to fitness. Localization of tissue-specific communities housed within CAMAs is particularly important, as these communities are potentially important contributors to vital metabolic functions of the holobiont.