Dataset: Sponge Disease Transmission - Secondary Metabolites
Deployment: Bahamas_Gochfeld

Temporal changes in biochemical, physiological and microbiological associations in the Aplysina cauliformis holobiont over the course of transmission of Aplysina Red Band Disease (ARBS) were investigated in two experiments, one performed in July and one performed in January. In both experiments, healthy and ARBS-affected sponges (n = 21-24 of each) were marked in situ at North Norman’s reef in the Exuma Cays, Bahamas. Healthy sponges were collected, labeled and a subsample (10 cm) was removed into an individual resealable plastic bag underwater to serve as an "initial" sample. The remainder of each of these healthy sponges was randomly attached to either a healthy in situ sample or to the active red band on a diseased in situ sample using a cable tie. In July, randomly selected pairs of healthy-healthy and healthy-diseased sponges were collected on days 3, 6 and 9 to provide "final" samples. In January, randomly selected pairs of each type were collected on days 1, 3 and 9. Following final collection, all pairs were separated in the lab, and photographs were taken to confirm whether ARBS transmission had occurred.

Following collection of initial and final samples, the sponges were subsampled for several analyses. Only sections of healthy tissue were used, even from the ARBS-affected sponges (Gochfeld et al. 2012, Marine Ecology Progress Series; Gochfeld et al. 2012, Journal of Chemical Ecology; Olson et al. 2014). Subsamples were collected for measurement of chlorophyll a, total protein, secondary metabolite profiles, and microbial community analysis. In addition, in January, subsamples were also collected for heat shock protein 70 expression analysis.

Analytical methods followed those of Gochfeld et al. (2012, Marine Ecology Progress Series) for chlorophyll a and total protein, and Olson et al. (2014) for microbial community assemblages. Secondary metabolite profiles used similar methods to those described in Gochfeld et al. (2012, Journal of Chemical Ecology) except that the samples were extracted three times in methanol prior to generating chemical profiles using HPLC. Areas under the curve for peaks that were consistently found in either in situ healthy and/or in situ diseased sponges were quantified. Heat shock protein 70 expression analysis was performed following methods in Sarkis et al. (2005).