Molecular cloning and expression of a coding CARD gene from Haliotis diversicolor in development and under stresses

In order to analyze the role of Caspase recruitment domain (CARD) of abalone in development and under stress, the full length cDNA of a coding CARD gene was cloned by RACE according to its partial sequence in transcritpome of Haliotis diversicolor. Its expression profile of development and stress was obtained by real time quantitative PCR. The cDNA sequence was named HdCARD and was1371 bp, with a 735 bp open reading frame encoding a protein of 244 aa (HdCARD) and containing a conserved CARD domain. Quantitative real-time PCR results indicated that HdCARD could be detected in all examined tissues, with the highest expression level in mucus gland. There was also expression of HdCARD in different developmental stages, with highest expression level during late veliger stage. There was a significant difference of HdCARD in hemocytes after a bacterial challenge/thermal/hypoxia stress. The RNAi of HdCARD could increase larval malformation rate in trochophore stage. Moreover, larval caspase-8 and DAD1 significantly rose, but larval caspase-3 significantly reduced. The results suggested that HdCARD might play a role in larval development, immunity, and under thermal stress and hypoxia stress.