鲇病原粘孢子虫米氏碘泡虫不同株系的比较  

Comparative study on different strains of Myxobolus miyairii in catfish Silurus asotus pathogen

作　　者：向乾 谭禄奇 彭建军[1,3] 石小威 杨承忠 赵元莙[1] XIANG Qian;TAN Luqi;PENG Jianjun;SHI Xiaowei;YANG Chengzhong;ZHAO Yuanjun(Animal Biology Key Laboratory of Chongqing Education Commission of China,College of Life Sciences,Chongqing Normal University,Chongqing 401331,China;Chongqing Key Laboratory of Conservation and Utilization of Freshwater Fishes,Chongqing Normal University,Chongqing 401331,China;School of Life and Health Sciences,Hunan University of Science and Technology,Xiangtan 411201,China;Guizhou Provincial Key Laboratory for Biodiversity Conservation and Utilization in the Fanjing Mountain Region,Tongren University,Tongren 554300,China)

机构地区：[1]重庆师范大学生命科学学院,动物生物学重庆市高校重点实验室,重庆401331 [2]重庆师范大学,淡水鱼类资源保护与利用重庆市重点实验室,重庆401331 [3]湖南科技大学生命科学与健康学院,湖南湘潭411201 [4]铜仁学院,贵州省梵净山地区生物多样性保护与利用重点实验室,贵州铜仁554300

出　　处：《水产学报》2024年第5期158-165,共8页Journal of Fisheries of China

基　　金：国家自然科学基金(31970409);重庆市自然科学基金(CSTB2022NSCQ-MSX0994);重庆市教委科学技术研究重点项目(KJZD-202300503);重庆市留学人员回国创业创新支持计划(cx2018108);贵州省梵净山地区生物多样性保护与利用重点实验室开放课题([2020]2003)。

摘　　要：为研究米氏碘泡虫不同寄生部位和不同地理分布的株系差异和遗传分化情况,实验基于其形态特征、组织向性、地理分布、18S rDNA序列相似度、遗传距离、系统发育,对米氏碘泡虫各株系进行比较分析。结果显示,米氏碘泡虫各株系孢子形态特征基本一致;米氏碘泡虫重庆株系1(鲇鳃腔膜寄生)、重庆株系2(鲇肠寄生)和江西株系(鲇肠寄生)间相似度为98.6%~99.9%,遗传距离为0.000~0.013;系统发育分析显示,米氏碘泡虫重庆株系2先与江西株系聚支,其形成的进化支再与重庆株系1形成姐妹群关系。研究表明,米氏碘泡虫并没有形成地理种群特有的单系,而是依据寄生部位形成肠寄生支系和鳃腔膜寄生支系。宿主种类相同的条件下,较之于地理隔离,寄生部位差异对于米氏碘泡虫种群分化的影响更大。Myxozoans are microscopic metazoan parasites which are recognized as a group of cnidarians that turned their free-living condition to parasitic life about 600 million years ago.There are more than 2600 species of myxozoans,which mainly infect freshwater and marine fish,with a few infecting amphibians,reptiles,birds and mammals.Myxobolus Butschli 1882,with more than 900 species recorded to date,is the most speciose and widespread genus in Myxozoa,some of which can cause serious fish disease and bring great economic loss in fishery.Myxobolus miyairii Kudo 1919 is a pathogenic parasite of catfish Silurus asotus Linnaeus 1758,which is an economically important fish in China.This parasite was first discovered in Japan and subsequently found in China and Russia,successively.To investigate the strain divergence of M.miyairii from different parasitic sites and localities,the comparative study was carried out based on morphological characters,histotropism,geographic distribution,18S rDNA sequence similarity,genetic distance and phylogeny.The myxospores of Chongqing strain 1(infecting gill cavity membrane of S.asotus)of M.miyairii were ellipsoidal in shape with pointed anterior end and blunt posterior end.The myxospores of Chongqing strain 1 were 13.08±0.70(10.56-13.83)μm in length and 6.09±0.55(4.94-7.17)μm in width.The two polar capsules positioned at the anterior end of the spores,which were pyriform and equal,measured 4.97±0.39(4.09-5.87)μm long and 1.34±0.18(0.98-1.87)μm wide.The morphology of Chongqing strain 2(infect intestine of S.asotus)was generally consistent with the Chongqing strain 1.The results of principal component analysis and Mann-Whitney U test on morphometry of the two strains further confirmed their morphological consistency.The similarity and genetic distance among Chongqing strain 1,Chongqing strain 2 and Jiangxi strain(infecting intestine of S.asotus)was 98.6%-99.9%and 0.000-0.013,respectively.Phylogenetic analysis showed that the Chongqing strain 2 and Jiangxi strain clustered together as

关 键 词：鲇 米氏碘泡虫 18S rDNA 株系比较 

分 类 号：Q958.9[生物学—动物学] S943[农业科学—水产养殖]