Integrating the Vibrio-resistance phenotype and gene expression data for discovery of markers used for resistance evaluation in the clam Meretrix petechialis

In this study, gene expression data were used to select resistance-associated markers that indicate resistance phenotypes in the clam Meretrix petechialis. A total of 1772 clams from 23 full-sibling families were subjected to a Vibrio challenge test, and the results showed significant variation in resistance to vibriosis among different families. Three of the most resistant families and three of the most susceptible families were selected for screening of resistance-associated markers. Then, among 22 genes, 12 demonstrated a significant change in expression, and their expression levels were further analysed by t-test and linear regression analyses, respectively, between resistant and susceptible families. Overall, the results showed that the basal expression levels of Big-Def, BIRC7, NFIL3, CTL9 and Bax were associated with Vibrio-resistant phenotypes and could be considered candidate resistance-associated markers. Further, two M. petechialis strains that differed in Vibrio resistance were used to examine the effectiveness of these five resistance-associated genes. The results further confirmed that the expression of BIRC7 and NFIL3 were associated with Vibrio-resistant phenotypes. This study integrated the Vibrio-resistance phenotype and gene expression data for resistance evaluation and provided potential markers for the genetic breeding of high Vibrio-resistance strains in the clam M. petechialis.