Abstract
Opsin is a fellow of the G protein-coupled receptors (GPCRs)
superfamily. It can be divided into visual and non-visual opsins
according to whether they are directly involved in visual imaging. Opsin
plays an important role in visual image formation and the regulation of
non-image forming functions such as circadian entrainment in the growth,
development and evolution of fish. Crimson snapper is mainly found in
the Indo-West Pacific and the southern part of the East China Sea and
the South China Sea. It is one of the most influential economic fish in
the South China Sea. In order to study the existence and expression of
opsin gene in Crimson snapper, we sequenced the genome and tissue sample
transcriptome of Crimson snapper. In this study, 32 opsin genes were
identified from the genome with the length of 1061 bp - 86203 bp
distributed on 15 different chromosomes. The analysis of opsin gene
family of Crimson snapper showed that the sws2 was expanded with two
copies than that of Zebrafish. Domain and motif analysis revealed that
all the 32 opsin sequences had 7TM receptors, and Crimson snapper opsin
family contained 10 common motifs. The expression level of opsin gene,
confirmed by RT-qPCR, was analyzed by using nine tissues transcriptome
databases of Crimson snapper. The results showed that almost opsin genes
were highly expressed in the retina and brain,except opn7a and opn7b
which were expressed in intestine and red skin, and almost no expression
in other tissues.