Epidemiological Investigation Of Enterocytozoon Hepatopenaei In Penaeus Vannamei From Liaoning Province And Transcriptome Analysis Of Diseased Hepatopancreas

Enterocytozoon hepatopenaei(EHP)has been widely popular in the main prawn producing areas of China in recent years,which has caused great economic loss to the prawn industry of Vanapayana.This study mainly includes two aspects of experimental content:epidemiological investigation of penaeus hepatica and transcriptome analysis of hepatopantral tissues of penaeus hepatica infected with hepatopantral cystis in Liaoning region,with the purpose of understanding the epidemic situation of hepatopantral cystis in Liaoning region,and exploring the pathogenesis characteristics and transmission routes of hepatopantral cystis.At the same time,high-throughput sequencing was used to detect the differences in transcription expression of hepatopantral and pancreatic tissues before and after the disease,and to screen the different genes,so as to provide theoretical basis for the prevention and treatment of hepatoenterocystis.Sampling and testing were carried out in 5 vannabine breeding areas(Shenyang,Dalian,Panjin,Yingkou and Dandong)in Liaoning province.Investigation was conducted from the perspectives of region,water salinity,different specifications of prawns in the same growth cycle,pond disinfection and breeding cycle.The detection results showed that the EHP detection rate of samples collected from different prawn breeding ponds in 5 regions was generally high,with the infection rate of 41.4% in Panjin region and above 50% in other regions,among which the highest EHP detection rate in Yingkou region was 75.8%.The infection rates in freshwater ponds and ponds with salinity greater than 1 were 61.4% and68.4%,respectively.In the middle stage of vannamei culture(30d-60d),the infection rate of EHP in the shrimp with small size and slow growth was higher than that in the normal growth of Vannamei.The EHP infection rate was 62.0% in the ponds where the bottom was cleaned and disinfected before prawn breeding,which was lower than that of prawn without cleaning and disinfecting(70.7%),but the infection rate of enterocystis hepatica was still at a high level.In addition,with the lengthening of the breeding time,the infection rate of litavarix vannamei will gradually increase.The EHP rate of litavarius vannamei was 29.2% in the initial stage of breeding,63.8% in the mid-term detection and 79.6% in the later stage of breeding.At the same time,other organisms and original pond water in the prawn culture pond ecosystem were collected for testing,and it was found that EHP nucleic acid positive could be detected in the diseased pond water,wild fishes and benthic snails.The infection of Crucian carp and Artemia by EHP further confirmed that the mechanical hosts of hepatoenterocystisare extensive.Through the deeply cell worm infection hypodermal tissue before and after study of differentially expressed genes,in order to further understand deeply the cell with insect,achieved to offer reference to the interactions,using high-throughput sequencing technologies deeply cell to infection of worm and worm uninfected deeply cell liver transcriptome sequencing pancreatic tissue,sequencing is acquired the sequence of removing connectors for splicing unigenes,and tested by rt-pcr gene differential expression.Transcriptome sequencing samples received 173908709 sequence,is obtained by sequence after joining together,a total of 20946 unigenes,will infection group were compared with healthy controls data analysis,found that the amount of differentially expressed genes in 131,raised the expression of genes in these accounts for 86,down expression of genes of 45,after it has been verified by rt-pcr statistical differences in gene sequencing result is reliable.The expression levels of growth and development related genes such as serotonin receptor and Chymotrypsin BII in the host tissues were down-regulated after hemoptysis parasitioides penaeus,suggesting that hemoptysis may inhibit the normal growth of the host.The expression levels of most immune-related genes,such as C-type Lectin and Serine protein kinase,were up-regulated in host subjects,indicating that the immune mechanism that stimulated the host after the parasitism of hepatoenterocellular cysts was activated to some extent and antagonized by sporozoa.