【作者】 王慧春；

【导师】 管越强；

【作者基本信息】 河北大学 ， 水生生物学， 2010， 硕士

【摘要】 将虾青素添加到凡纳滨对虾(Litopenaeus vannamei)配合饲料中,从抗氧化角度入手,在个体、细胞和分子水平研究虾青素对凡纳滨对虾免疫防护和抗氧化酶基因的影响,以期全面评价虾青素在改善凡纳滨对虾的生理功能和提高凡纳滨对虾抗病力等方面的作用,进而推测虾青素的作用机理。虾青素对感染WSSV的凡纳滨对虾的免疫防护作用。评价指标有：血液免疫指标(血细胞计数、血细胞吞噬百分比、血细胞吞噬指数、血清抗菌活力、血清溶菌活力、血清酚氧化酶活力、血清抗超氧阴离子自由基活力),WSSV感染后的累积死亡率及相对免疫保护率。实验证明：饲料中添加80 mg/kg虾青素可显著提高实验组对虾的血液学指标(p<0.05)；实验组中感染WSSV的凡纳滨对虾累计死亡率为76.3%,免疫保护率为23.7%：虾青素对凡纳滨对虾抗氧化酶基因转录的影响。采用β-actin作为内参,用半定量PCR法研究添加虾青素作为抗氧化剂对凡纳滨对虾肝胰腺MnSOD、CAT和GPX 3种抗氧化酶基因转录水平的影响。结果表明,饲料中添加80mg/kg虾青素能明显提高抗氧化物酶系统包括SOD、CAT、GPX的mRNA水平(p<0.05)。针对养殖对虾病害频发的现状,本实验还初步研究了中国明对虾(Fenaeus chinensis)养殖水体理化因子变化与对虾白斑综合症病毒(WSSV)感染率的相关性。通过对养成池的水质监测及对虾WSSV检测,发现在WSSV感染率较高的的8月份,水体溶解氧迅速下降,温度处于WSSV易感的温度范围,pH值变化剧烈,,铵盐和硝酸盐含量骤然升高。这说明恶化的水体环境能增加对虾WSSV的易感性,或使潜伏感染WSSV的对虾产生应激反应引起急性感染死亡更多还原

【Abstract】 In this paper, the astaxanthin was added to the feedstuff of Litopenaeus vannamei. The effect of astaxanthin upon L. vannamei was studied in terms of anti-oxidation at individual cell and molecular levels so as to give an overall appraisal of astaxanthin used to improve L. vannamei physiological function and resistance to disease. Furthermore the mechanism of astaxanthin action could be predicted. The effect of astaxanthin to L. vannamei is discussed as below:The effect of astaxanthin to L. vannamei after challenged with WSSV; the effect of astaxanthin on transcription activity of anti-oxidase gene in L. vannamei liver. Evaluation factors were selected according to various experiment aims:immunological index in hemolymph(total haemocyte counts, phagocytic percentage of haemocyte, phagocytic index, serum anti-bacterial activity, serum lysozyme activity, serum phonoloxidase activity, serum anti-superoxide radical activity); resistance to disease (the mortality of L. vannamei after challenged with WSSV); index in molecular level(SOD CAT and GPX mRNA leve 1).The results showed that astaxanthin could increase immunological index in hemol-ymph(p<0.05), the mortality of L. vannamei after challenged with WSSV was 76.3% in the supplementation level of 80 mg/kg group, the relative percent suvrival(RPS)valu e of the test group reached 23.7%. The effect of astaxanhin on gene expression of an ti-oxidase was determined using semiquantitative reverse transcription polymerase chaim reaction(RT-PCR) analysis, the results suggest that astaxanhin can impove the transcri ption acivities of anti-oxidase gene in L. Vannamei liver(p<0.05).In view of frequent occurrence of epidemic disease in shrimp culture, this paper studies on the relationship between WSSV and environmental factors in shrimp culture ponds of Fenaeus chinensis. By water quality monitoring and WSSV detection, it was shown from the analysis that when WSSV of cultured shrimp outbreak in august, dissolved oxygen in the culture ponds decreased rapidly, the variable ranges of temperature was from 24.3℃to 28.4℃in which F. chinensis can easily suffer from WSSV, pH changed acutely, ammonium and nitrate contents in the water increased suddenly. Apparently, aggravation of water quality can decrease the resistance of F. Chinensis and suffer from WSSV easily, while penaeid acute viremia survivors may die of hyperirritability.更多还原