A study using amplicon sequencing of the viral mcp gene of dinoRNAVs to analyze their dynamics in the reef-buliding coral <i>Porites c.f. lobata</i> at three reef zones around Moorea, French Polynesia

These data are from a study that used amplicon sequencing of the viral major capsid protein (mcp) gene of positive-sense single-stranded RNA viruses known to infect symbiotic dinoflagellates ('dinoRNAVs') to analyze their dynamics in the reef-building coral, Porites lobata. The investigators repeatedly sampled 54 colonies across three environmentally distinct reef zones (fringing reef, back reef, and forereef) around the island of Moorea, French Polynesia over a three-year period and spanning a reef-wide thermal stress event. Temperature was measured in each reefzone to quantify differences in temperature according to reef zone and during the thermal stress event.

Images were also taken of all colonies at each sample point in order to analyze colony health and partial mortality. By the end of the sampling period, 28% (5/18) of corals in the fringing reef experienced partial mortality versus 78% (14/18) of corals in the forereef. Over 90% (50/54) of colonies had detectable dinoRNAV infections. Reef zone influenced the composition and richness of viral mcp amino acid types ('aminotypes'), with the fringing reef containing the highest aminotype richness. The reef-wide thermal stress event significantly increased aminotype dispersion, and this pattern was strongest in the colonies that experienced partial mortality. Amplicon sequencing was also used to amplify the D1–D2 region of the 28 S large subunit (LSU) nuclear ribosomal RNA gene and to ultimately identify the dominant lineages of Symbiodinaiceae (the hosts of dinoRNAVs) in all P. lobata colonies. All colonies were dominated by Cladocopium C15 symbionts. These findings demonstrate that dinoRNAV infections respond to environmental fluctuations experienced in situ on reefs.