晒田环境胁迫对克氏原螯虾卵巢组织、卵黄蛋白原及营养物质代谢的影响.

【Objective】The present paper aimed to study the histological characteristics of the ovaries, the changes in concentration of vitellogenin and nutrient metabolism level of Procambarus clarkii under the stress of sunning field, explore the relevant mechanism of nutrient changes during ovarian maturation process of P. clarkii, and the results provided a reference for the improvement and standardization of the production operation of P. clarkii ovary maturity which was promoted by environmental stress in sunning field.【Method】The experimental subjects were divided into sunning field group P. clarkii and control group P. clarkii. The female P. clarkii were collected at 0, 3, 7 and 10 days of the sunning field stress respectively. At each sampling time point, the ovaries were taken for paraffin section and HE staining. The ovaries, hepatopancreas and serum of samples were collected, of which the expression and concentration of vitellogenin mRNA and the level of nutrient metabolism were detected. 【Result】Under the sunning field stress, four ovarian development stages were identified, including the pre-vitellogenesis stage (stage Ⅰ, ovary was yellow, oocyte diameter 150-250 μm), primary vitellogenesis stage (stage Ⅱ, ovary was orange, oocyte diameter 250-600 μm), secondary vitellogenesis stage (stage Ⅲ, ovary was brown, oocyte diameter greater than 600 μm), mature stage (stage Ⅳ, ovary was dark brown, oocyte diameter greater than 1000 μm). At 0 days of the stress, the ovarian maturation rate of female P. clarkii in the sunning field group was similar to that in the control group. At 10 days of experiment, the ovarian maturation rate of the female P. clarkii in the sunning field group rose to 96.67%, while the control group rose to 60.00%. With stress time increasing, the relative expression of vitellogenin mRNA in the ovaries and hepatopancreas of the control group and the sunning field group increased, of which vitellogenin mRNA in the hepatopancreas was greater than that in the ovaries. Over the time of experiment, the total expression level of vitellogenin mRNA of the hepatopancreas in the sunning field group and the control group was greater than that in the ovary, and the contribution rate of the hepatopancreas was greater than that of the ovary. The concentration of vitellogenin in the ovary, hepatopancreas, and serum in the sunning field group and the control group increased over time. The concentration increase of vitellogenin in the sunning field group was significantly higher than that in the control group. There was extremely significant positive correlation between hepatopancreas vitellogenin concentration and ovary vitellogenin concentration, between hepatopancreas vitellogenin concentration and serum vitellogenin concentration, between ovary vitellogenin concentration and serum vitellogenin concentration (P＜0.01). With stress time increased, hemocyanin (Hem), total protein (TP), lactic acid (LA) and glucose (Glu) content in female P. clarkii of both groups all showed a decreasing trend, the decrease range of sunning field group was greater than control group; And contents of triglyceride (TG) and cholesterol (TC) showed an increasing trend, and the increasing range of sunning field group was greater than that of control group.【Conclusion】Four developmental stages in ovaries of P. clarkii were identified during environmental stress of sunning field. As stress time passed by, the relative expression and concentration of vitellogenin mRNA in different tissues of P. clarkii increased, of which contribution rate in hepatopancreas was greater than that in ovary. The contents of Hem, TP, LA, and Glu decrease, and the contents of TG and TC increase in P. clarkii, indicating that environmental stress of sunning field has a positive effect on ovarian development. [ABSTRACT FROM AUTHOR]