PRELIMINARY STUDIES ON THE EARLY DEVELOPMENT AND THE EXPRESSION PATTERN OF OPSIN GENES OF EMPEROR RED SNAPPER(LUTJANUS SEBAE)

In this study, we observed the morphological characteristics and used qRT-PCR to analyze the expression pattern of four opsin genes during the early development of Emperor red snapper. The eggs of Emperor red snapper were a type of buoyancy that had spherical shape and one oil globule. Fertilized eggs hatched in 24 hours at the temperature of (24.50.5)℃, and there were 6 phases and 18 stages in the development of the embryo. After 1215 days, the larvae developed into juvenile. After 3035 days, the juvenile developed into young fish. We detected the expression of four opsin genes (LWS, SWS1, SWS2 and RH) at 7 embryo stages and 2 larvae stages. All four genes were markedly expressed at the 1/2 epiboly stage, the closure of blastopore stage and the optic capsule stage (P0.05). The expression level of the four genes was the highest at the closure of blastopore stage. At other stages the expression was largely decreased. However, the expression was slightly increased at 2 larvae stages compared to the hatching stage. Our results suggested that the expression of the four opsin genes in the early development was closely associated with the formation of the neural embryo of Emperor red snapper.