福建霞浦海区刺激隐核虫虫株鉴定及生活史观察

The Strain and Life-cycle of Cryptocaryon irritans Isolated from Pseudosciaena crocea Cultured in Xiapu,Fujian

分离患"白点病"的大黄鱼(Pseudosciaena crocea)鱼鳃上的刺激隐核虫(Cryptocaryonirritans),提取基因组DNA,PCR扩增rDNA-ITS-1基因并进行序列分析.结果显示:该虫的rDNA-ITS-1序列与刺激隐核虫PYH4.12株及Chiayi虫株完全一致,表明福建霞浦流行的"白点病"病原为刺激隐核虫PYH4.12株或Chiayi株.以褐菖鮋(Sebastiscus marmoratus)为宿主,建立了该虫株的传代体系,对其生活史进行了详尽的观察,并收集各期虫体,为构建基因文库、功能基因的鉴定和分析奠定基础.

A strain of Cryptocaryon irritans was isolated from cultured Pseudosciaena crocea in Xiapu,Fujian,maintained and passaged successfully in aquaria by using Sebastiscus marmoratus as a host.The life cycle and the morphological characters of each phase were observed.Meanwhile,its genomic DNA was extracted and used as a template DNA to amplify the gene fragment of internal transcribed spacers of ribosomal DNA（rDNA-ITS-1） by using PCR.The sequence of rDNA-ITS1 was then analyzed and aligned with the known homological sequences of various strains of Cryptocaryon irritans.The result showed that both the morphological characterization and the sequence of rDNA-ITS-1 were identical to those of PYH4.12 and Chiayi strain,which inferred that the pathogen of ＇white spot disease＇ endemic in cultured Pseudosciaena crocea in Xiapu,Fujian is PYH4.12 or Chiayi strain of Cryptocaryon irritans.It provided with large numbers of the parasites for establishment of cDNA libraries and analysis of function genes.