Investigation And Taxonomic Study Of Parasitic Myxozoan In Crucian Carp In Jiangsu Region

Jiangsu province is the main breeding area of crucian carp in China. Since the1990s, the region breeding crucian carp has been suffered from the problem that is infection with myxosporeans, and myxosporidiosis has caused serious economic losses of local crucian carp farming, seriously affected the development of Jiangsu aquaculture. In the present study, we investigated and studied of myxosporeans parasitic in crucian carp in Jiangsu region, and established a specific and sensitive PCR test method for M. honghuensis, so as to provide some theoretical basis for life cycle of myxosporeans and prevention of myxosporidiosis.1. Investigation of myxosporeans parasitic in crucian carp and taxonomic study. We investigated pond-reard crucian carp of Yancheng、Dafeng、Sheyang、Binhai city form July2011to April2012. In this survey, we found five myxospore species from throat, gill and liver of crucian carp. According to the morphologic features and18S rRNA genes sequence of these myxosporeans, the results of classification and identification are as follow:M. cultus Yokoyama, Ogawa &Wakabayashi,1995、M. wulii Landsberg&Lom,1991、M. ampullicapsulatus Zhao et al,2008、M. honghuensis Liu,2011、Henneguya doneci Schulman,1962、Thelohanellus wuhanensis Xiao&Chen,1993. Among the eight species, M. ampullicapsulatus and M. wulii could cause the severest mortality on the fish farms. We studied the taxonomic and phylogenic relation of four myxosporean based on18S rDNA, and eked out the five kinds of Myxosporean morphology and18S rDNA information.2. Investigation of actionspore types in pond breeding crucian carp and taxonomic study. In this present study, four actinosprean types, Echinactinomyxon1、 Triactinomyxon、Raabeia、Echinactinomyxon2collected from the oligochaete Branchiura sowerbyi Beddard collected from crucian carp(Carassius auratus gibelio) ponds in Changzhou city and Liyang city, Jiangsu province. DNA sequences analysis, showed the Echinactinomyxon type1examined present99.7%genetic similarity to M. wulii, thus the Echinactinomyxon type1should be considered as M. wulii. On the basis of morphology data, these four actinosprean types presented in this study differs from those already known in the literatures, and were firstly reported in China.3. A detecte method for M. honghuensis by nest-PCR. Genome DNA solution of M. honghuensis was diluted to100、10-1、10-2、10-3、10-4、10-5、10-6、10-7with sterile distilled water. And then nest PCR reactions were carried out using the universal eukaryotic primers ERIB1 &10and the M. honghuensis specific primer Nest-F &R. After the end of reaction, comparing with the result of one-round PCR and nest-PCR by agarose gel electrophoresis, we found that the sensitivity of nest-PCR was102-103time higher than the one-round PCR.