2배체와 3배체 참굴의 계절적 성장변화와 조직별 IGF system의 발현

Abstract

In Korea, the Pacific oyster, Crassostrea gigas is the essential aquaculture species, moreover, diploid has mainly occupied the product quantity. Furthermore, research on triploid that promotes growth has recently been reported. While, the insulin-like growth factor (IGF), known as a significant growth factor in vertebrates, has been studied mainly in fish, and the association between growth and IGF expression was reported in some bivalves. Therefore, in this study, the seasonal somatic growth of the diploid and triploid Pacific oysters was investigated, and the relationship of the growth of each ploidy oysters and the IGF system (IGF-I, IGF binding protein, and IGF-I receptor) was identified by comparing the mRNA expression of the IGF system in each tissue. The diploid and triploid Pacific oysters were measured condition index (CI) and tissue weight rate (TWR) by shell length, shell height, shell width, total weight, and soft tissue weight for every month. Moreover, adductor muscle, digestive gland, gills, labial palps, and mantle edge were collected to confirm mRNA expression of the molluscan insulin-related peptide (MIP), IGF binding protein complex acid labile subunit (IGFBP_ALS), and Crassostrea gigas insulin receptor-related receptor (CIR). As a result, the CI and TWR were shown the same pattern. Both values were temporarily increased in May in diploid, and increased from January to May in triploid. mRNA expression of MIP, IGFBP_ALS, and CIR was showed the same tendency in all the tissues used in this experiment, and expression of the IGF system was higher in triploid than diploid. In addition, mRNA expression of CIR in the adductor muscle of diploid and triploid was increased in summer season when temperature increased. The pooled estimate value of each IGF mRNA expression was a high level in November, February, and August in diploid, however, triploid has a high level in spring to autumn, and these results are suggested that it can relate to spawning seasons of Pacific oysters. Therefore, the results of this study will be used as base data on seasonal growth of the diploid and triploid Pacific oysters, moreover, it can be suggested an indicator of the expression of growth factors.