Preliminary Research On Regulation Mechanism Of FSHR In Reproduction And Development Of Sepiella Japonica

Sepiella japonica is an economically important cephalopod in the East China Sea.However,with the serious decline of the resources of S.japonica and the breakthrough of the bottleneck of artificial breeding technology,the large-scale artificial propagation and resource conservation work have been carried out in the coastal areas of China.In this paper,some tissues of S.japonica,including brain,optic lobe,intestines,liver,pancreas,stomach,and nidamental gland were observed with histological technology and the histological structures of these tissues were stated.At the same time,the FSHR gene was cloned,the tissue-specific expression was analyzed,and SjFSHR location in several different functional lobes was studied.According to the results,the regulatory role of SjFSHR in S.japonica reproduction was preliminarily speculated.HE staining results showed the histological structure of the brain,optic lobe,liver,intestine,pancreas,stomach,and nidamental gland of S.japonica.The partial sequence of SjFSHR gene was cloned by RACE method.The results of amino acid alignment showed that the sequence of SjFSHR shared high similarity with Octopus bimaculatus FSHR and the ORF of the O.bimaculatus FSHR.The phylogenetic tree analysis of SjFSHR showed that the gene of SjFSHR was closely related to O.bimaculatus FSHR.RT-PCR results showed that SjFSHR gene was transcribed in the retina,muscle,pancreas,brain and optic lobe of stage V male S.japonica,and SjFSHR gene was transcribed in the liver,intestine,retina,heart,muscle,gill,skin,stomach,pancreas,brain,optic lobe,nidamental gland and accessory nidamental gland of stage V female S.japonica.The qRT-PCR results showed that SjFSHR was transcribed the most in the liver of S.japonica,followed by brain and optic lobe.The results of in situ hybridization showed that SjFSHR had different intensity signals in the vertical lobe,the anterior basal lobe,the sub vertical lobe,the sub foot lobe,the posterior foot lobe,the upper frontal lobe and the lower frontal lobe,but no signal in the abdominal optic nerve connection,the anterior connecting lobe and the wrist lobe.There were obvious signals in inner granular cell layer,outer granular cell layer,central medulla and marginal medulla.All these results suggested that FSHR might play an important role in reproductive regulation of S.japonica.