Expression Profiling Of Myosin Va, CHH And Timeless Genes In Chinese Mitten Crabs At Different Developmental Stages

Migration is an instinctive behavior of animals.It is the animal's response to the internal and external environmental changes,which is often seasonal and carried out on a certain route.Migration of aquatic animals(such as fish and crustaceans,etc.)is particularly known as reproductive migration or feeding migration,etc.Only a few species of crustaceans,such as the Chinese mitten crab(Eriocheir sinensis),are migratory crustaceans.In natural habitats,the Chinese mitten crab has two migrations throughout its life.The aims of the two migration are different and in opposite directions.To date,nevetherness,the mechanism of these timing and directional migration in crustaceans has not been studied clearly.Based on the three key factors(energy supply,muscle contraction,and circadian rhythm),three genes including Myosin Va,CHH and Timeless were selected for further gene expression analysis and functional investigation in this study.In the present work,a full-length cDNA of Myosin Va(named as EsMyoVa)from the Chinese mitten crab,E.sinensis,was cloned.Moreover,the gene sequence,functional structure,physical and chemical properties,and the rest were analyzed.The real-time quantitative PCR(RT-qPCR)was used to detect the relative expression level of the three genes in different developmental stages of larvae and different tissues of different gender immature and mature crabs.The results revealed that the there genes were widely expressed in all developmental stages of larvae and detected tissues.Furthermore,the expression level of the three genes fluctuated obviously in the fifth zoeal stage and the megalopa stage.The EsMyoVa was highly expressed in hepatopancreas,while the CHH was highly expressed in the eyestalks of different developmental stages and different gender immature and mature E.sinensis.The expression level of Timeless was higher in hepatopancreas and muscle of immature young crabs and it was only highly expressed in muscle of mature E.sinensis.The extensive tissue expression patterns,especially high expression in muscle and hepatopancreas,indicate that these three genes may play important roles in the growth,development,and energy supply of crabs during migration.In addition,RNAi technology was used to further explore the role of EsMyoVa gene in the growth and development of E.sinensis.The results showed that the silence of the EsMyoVa gene induced the decrease of body weight gain rate and the increased of mortality of crabs.