Whole genome analysis and specific PCR primer development for Vibrio coralliilyticus, combined with transcription and metabolome analysis of red spotting disease in the sea urchin, Strongylocentrotus intermedius

Abstract

Vibrio coralliilyticus is a notorious pathogen that causes disease in coral. Recently, we identified a pathogenic strain of V. coralliilyticus, Rb102, from farmed sea urchins that had "red spotting disease". In this study, we performed whole genome sequencing for Rb102 and compared the sequence with ten common aquatic pathogens. A specific PCR detection method was then developed for V. coralliilyticus. In addition, disease–resistant sea urchins and those suffering from red spotting disease were sent for comparative analysis of the transcriptome and metabolome. The complete genome was found to be 5758,353 bp and contains two large chromosomes (Chr1 and Chr2) and one plasmid. The groEL gene was chosen for the design of specific PCR identification primers. Differential transcriptome analysis between diseased and disease resistant groups revealed that there are 1845 differentially expressed genes (DEGs), with the largest number enriched in the purine metabolic pathway. Significant differences were detected between the two groups in 91 cationic metabolites and 43 anionic metabolites. Deoxyinosine was the most significantly down–regulated metabolite and is found in the purine metabolic pathway. The results of this study provide an important reference and data foundation for further study of "red spotting disease" in sea urchin farms.