哈维氏弧菌浸浴后凡纳滨对虾肠道组织病理变化及转录水平的免疫应答  

Pathological changes and transcriptional response to immersion infection by Vibrio harveyi in shrimp(Litopenaeus vannamei) gut

作　　者：夏青[1,2] 王宝杰[1] 刘梅[1] 蒋克勇[1] 王雷[1] 

机构地区：[1]中国科学院海洋研究所海洋生物学重点实验室,山东青岛266071 [2]中国科学院大学,北京100049

出　　处：《水产学报》2015年第10期1521-1529,共9页Journal of Fisheries of China

基　　金：国家科技支撑计划(2012BAD17B03)

摘　　要：为研究凡纳滨对虾在不同浓度哈维氏弧菌的浸浴攻毒作用下肠道损伤的动态发展过程及肠道免疫基因表达水平,采用组织切片探究对虾肠道组织形态,采用实时荧光定量PCR测定抗脂多糖因子基因（ALF）、对虾素基因（Pen-4c）和Crustin基因（Cru）以及溶菌酶基因（LZM）、脂肪酸结合蛋白基因（Fabp）的表达水平变化,并对肠道及水体中的弧菌数目进行监测。结果表明,哈维氏弧菌侵染后,在低浓度组侵染32 h、中浓度组侵染16 h及高浓度组侵染8 h后出现轻度感染,在低、中浓度组侵染40 h后及高浓度组侵染16 h后发生重度感染。Cru在低、中浓度组侵染24 h和高浓度组侵染16~24 h出现显著表达;ALF在低浓度组侵染24 h,中浓度组侵染8和16 h,高浓度组侵染16 h显著上升后;Pen-4c在中、低浓度组侵染8 h,高浓度组侵染8~16 h达到其表达量最大值;LZM在低浓度组侵染24 h,中、高浓度组侵染8 h有显著提高。攻毒后,3种攻毒剂量下弧菌数目均处下降趋势,弧菌在侵染0~8 h经口大量进入对虾肠道,至侵染32 h菌数回落。结论：随着弧菌浓度的提高和攻毒时间的延长,中肠组织损伤情况逐渐加重,上皮细胞形态改变直至溃散,黏膜褶皱形态发生皱缩及脱落,肌层发生损伤。肠道受到哈维氏弧菌侵染后,抗菌肽ALF、Pen-4c、Cru基因及LZM基因表达量迅速上调,能够及时做出免疫应答反应,从而阻止致病菌的侵染;Fabp表达量未显著增加。Vibrio has been widely recognized as a primary pathogen of many commercially cultured invertebrate species the world over. In order to characterize the dynamics of intestinal infection after Vibrio challenge,we investigated the pathological changes and transcriptional response in shrimp Litopenaeus vannamei midgut after bacteria immersion in multiple concentrations. The dynamic changes in intestinal morphology were explored under microscope. Changes in expression of immune genes including anti-lipopolysaccharide factor gene（ ALF）,penaeidin gene（ Pen-4c）,crustin gene（ Cru）,lysozyme gene（ LZM） and fatty acid binding protein gene（ Fabp） were quantified with qRT- PCR. In addition,the number of Vibrio in intestine and water was also monitored in time courses. To summarize the result,we found slight damage in intestinal tissue in lowconcentration group at 32 h,medium concentration group at 16 h and high concentration group at 8 h post infection. Severe damages were observed as dose of Vibrio increased and as infection time prolonged,such as the lowand medium concentration groups after 40 h or high concentration group after 16 h. Expression level of Cru gene increased at 24 h in lowand medium concentration and 16- 24 h in high concentration. ALF gene increased at 24 h in lowconcentration,8- 16 h in medium concentration and 16 h in high concentration. Pen-4c gene reached its peak value at 8 h in lowand medium concentration and 8- 16 h in high concentration. LZMgene was up-regulated at 24 h in lowconcentration and 8 h in medium and high concentration. Vibrio number in water in all three treatments decreased after infection. Cumulative bacteria in shrimp increased in intestine during 0- 8 h and decreased at32 h. To conclude,midgut damage became worse when bacteria concentration increased or the immersion time prolonged. Gut epithelial cells degraded and collapsed,mucosal folds shrank and ecclasis occurred,as well as the muscular layer was damaged. Within 40 h post infection,shrimp gut morphology deterio

关 键 词：凡纳滨对虾 哈维氏弧菌 浸浴攻毒 免疫基因 q PCR 组织病理 

分 类 号：S968.22[农业科学—水产养殖]