Heritability of resistance-related gene expression traits and their correlation with body size of clam Meretrix petechialis

Abstract

Gene expression variation can be considered as a phenotype, and it plays an important role in both acclimation and adaption. However, genetic variation of gene expression received much less attention than traditional commercial traits in aquaculture. To estimate the genetic variation and heritability of gene transcription in clam Meretrix petechialis, five Vibrio resistance-related genes were selected for gene expression analysis in the digestive gland, and an animal linear model was used to analyze data from quantitative real-time PCR (qRT-PCR). Among the five genes, BIRC7 showed significant additive genetic variations, the heritability of this gene of 12-month- and 15-month-old clams were 0.84±0.32 and 0.91±0.34, respectively. The heritability of other four genes (Bax, NFIL3, Big-Def, and CTL9) expression were low-to-moderate but not significantly expressed. Additionally, no significant phenotypic and genetic correlations between the BIRC7 transcription trait and body size were detected. This study highlights that certain gene expression variation is heritable and provides a reference for indirect selection of M. petechialis with high Vibrio resistance.