基于生殖调控轴理论的人工养殖曼氏无针乌贼性早熟机理研究

Cephalopods are widely distributed with many good characters (rapid growth, short life history, and strong adaptive capacity) and occupy a pivotal position in the marine food chain. Cephalopod is one of the largest and most potential protein resources in the sea, which has a broad prospect of industrialization development of mariculture. The common Chinese cuttlefish Sepiella japonica was once one of the four important ocean products in East China Sea and has always been love of the people with high medicinal and edible values. However, since 1970s, over-fishing the brood stock in spring flood outside the spawning grounds, in summer spawning grounds, and in winter season with the fishing of hairtail caused the wild stock severely damaged and on the verge of extinction. Study on artificial breeding and feeding technique were imperative in order to protect the natural cuttlefish resources and development of this species. Currently, under the condition of artificial breeding, gonadal precocity which caused the body size diminished seriously restricted the economic benefits of artificial breeding. Based on this condition, Sepiella japonica reproductive regulation axis will be illuminated in this project and the key molecules of neuron peptides in the axis will be identified. With the guide of the cuttlefish reproductive regulation axis, the activation and swallowing mechanism, signal transduction mechanism, and the physiological function regulation of the reproductive related neuropeptide receptors will be researched; multi-level functions and expression regulation mechanism of cuttlefish neuropeptides in the gonad development will be clarified; relation between the reproductive related neuropeptides and GtH and sex steroid hormones will be explored under the cephalopods reproductive regulation axis. The results might provide certain theoretical support for solving the problem of the gonadal precocity in cultured Sepiella japonica.

头足类是海洋中最大、最具潜在价值的蛋白质资源之一，具有广阔的海水养殖产业化发展前景。曼氏无针乌贼曾是我国东海区“四大海产”之一，具有较高药用和食用价值，是潜在的优良养殖种类，但人工养殖中普遍存在的性早熟、个体小型化问题严重制约其经济效益。基于此，本课题在已初步摸清温度和光周期对其性腺发育影响、以及获得的神经肽GnRH（及受体）、FMRFamide、LFRFamide基因的cDNA全长和时空表达的基础上，以生殖调控轴理论为导向，阐明曼氏无针乌贼生殖调控轴关键分子；开展神经肽受体的激活与内吞机制、信号转导机制和生理功能调控研究；在细胞、组织与器官和个体水平多层次阐明神经肽在性腺发育中的功能与表达调控机制；探究神经肽与GtH和性类固醇激素之间在生殖调控轴中的相互关系，为解决人工养殖曼氏无针乌贼性腺早熟、体型小的问题提供理论支持。

头足类是海洋中最大、最具潜在价值的蛋白质资源之一，具有广阔的海水养殖产业化发展前景。曼氏无针乌贼曾是我国东海区“四大海产”之一，具有较高药用和食用价值，是潜在的优良养殖种类，但人工养殖中普遍存在的性早熟、个体小型化问题严重制约其经济效益。基于此，本课题围绕项目研究目标，应用细胞生物学和分子生物学技术，完成了曼氏无针乌贼神经肽NPF、FMRF、PRQFV及其受体基因NPFr、FMRFr-GPCR、FMRFr-NaC、QRFPr，以及与生殖密切相关的FSHR的克隆与鉴定，并对基因的序列特征进行了分析；并采用RT-PCR、qPCR、ISH、IHC、亚细胞定位等技术解析了上述基因mRNA 在曼氏无针乌贼机体不同组织中的分布、定位特征和性腺不同发育时期的分子动态变化情况，初步揭示了神经肽的生殖、免疫和摄食调控功能。为解决人工养殖曼氏无针乌贼性腺早熟、体型小的问题提供理论支持。