The mode of action of neuropeptide in gametogenesis and application to artificial induction of gonad development in bivalves

Representative Organization: Tohoku University

2016/04/01 - 2017/03/31

Onagawa Bay and other experimental waters

Others

Gonadotropin releasing hormone (GnRH) has been suggested to be useful for manipulation of sex and maturation in scallop. We aim to identify the GnRH receptor (GnRHR) cDNA from the scallop and plan to perform transcriptome survey and PCR cloning. In order to understand the mechanism of larval settlement in Pacific oysters, we plan to quantitatively analyze the differentiation and development of neurons in larval developmental process from fertilized egg through settled spat of oyster.

We identified the candidate fragment of scallop GnRH receptor (GnRHR) cDNA by the transcriptome survey and isolated scallop GnRHR cDNA by PCR cloning. High expression of GnRHR at early stage of sexual maturation in the scallop suggested that GnRH of the scallop functions to differentiation of gonia at early stage of development of ova and sperms. These results strongly suggested that GnRH is available for sex manipulation and artificial induction of gonad development in this species. As a result of quantitative analysis of the differentiation and development of neurons during larval development from fertilized egg through settled spat of oyster, dopamine, norepinephrine and serotonin neurons were differentiated at the gastrula and D-shaped larva stages The contents of these monoamines increased from the larvae grew up to 100um of shell size and reached. The peak just before and after settlement stages. It was suggested that these three types of neurons control settlement and metamorphosis of larvae in oyster from these results.

FY2016 The mode of action of neuropeptide in gametogenesis and application to artificial induction of gonad development in bivalves