The Pathology Change Of Duck Plague And Cloing Of Gene CD4 Of Duck

There were one hundred and eighe 35-day old Cherry vellay ducks randomly divided into 2 groups:72 for the test group and 36 for control group, breed insulatly. The pathological model of Duck Plague(DP)was duplicated through inoculating Duck Plague Virus(DPV) intramuscularly. Observations of clinic symptoms, pathological changes of optical microscope and transmissional electron microscope were carried out on the ducklings, the serum biochemical value and cellfactor was determined 1d,3d,6d post inoculation. Because of immunity suppression, in this reasearch, we cloned duck CD4 gene to provide rationale for illuminating the mechanism of Duck Plauge.The clinic symptoms showed that:the food appetite infcted ducks was decreased when 4d post inoculation, alo laxata frowardly, the dejecta was green or gray, the cloaca was flare,ectopia cloacae, there was serosity excretion in infected ducks'eyes, excretion was exuded in cavitas nasi,and then died with the anhelation; head and swelling nape 5d post inoculation. The death rate was 48.6%.The determination of serum biochemical value and cell factor value showed that:the effection was exist of serum biochemical value by virus infection. The ALT,AST,LD,AMY value of infection group was higher than control group 3d post inoculation obviously, ALT/AS,ALB,GLB,TP,A/G was lower, the value of infection group of ALP,CK,TNF-αwas higher than control group at first, then lower, and there was no difference between infection group and control group of Cor.Histological anatomy result were showed that:some liver cells were buddle destructured and some were adipose degenerated at first, adipose degeneration was intensified 4d post inoculation, and at last, congestion was intensified, and the cellular necrosis focus generally distributed; lymphocyte were got together in the stratum submucosum of esophagus, there was nearly no mucosa last 4d post inoculation, at the same time, lamina propria was congested,hemorrhaged or necrosised at last; in the intestinal tract, the number of beaker cells were increased at the first, folliculus lymphaticus were found in the prolification 2d post inoculation, lymphocyte were decreased in the folliculus lymphaticus, hemorrhage and necrosis happened in the folliculus lymphaticus 5d post inoculation; renal cells were necrosised at the period of 2d post inoculation, and some of them were ablated into the lumens of renal tubule,the tissue was engorge and hemorrhaged with inflammatory cell infiltrate, some renal tubule had lost their virgin structure 5d post inoculation; in the abdominal salivary gland, the tissue had necrosised 4d post inoculation, and there was lipid droplet in the endothelial cell of gland alveolus, with the development of pathogenetic condition, the number of lipid droplet was increased, necrotic area increased; the change of cardiac muscle was not manifest, but hemorrhaged in the day of 2 post inoculation, and the endocardium was hemorrhaged 4d post inoculation; there were cellular necrosis focus in the white pulp of spleen 2d post inoculation, spleen looked like starry sky because of cavitates at the period of 3d post inoculation, the area of necrosis accreted at the later stage;the medullary substance of thoracic gland was necrosised severity, the number of lymphocyte were decreased, and the necrosis were intensitied at last; the number of lymphocyte in the medullary substance and brain mantle were all decreased in bursa of Fabricius, the medullary substance was necrosed at the same time, the necrosis were intensitied in the folliculus lymphaticus at last.The results of observation by transmission electron microscope were showed that: there was macrophage that swallowed xenobiotic and tropism granular leukocytes in the spleen 1d post inoculation, some endocytoplasmic reticulum was broadened and some was electron density, then several dead cells were found, there was macrophage that swallowed dead cells 5d post inoculation; virus were found in thoracic gland cells Id post inoculation and dead cells 2d post inoculation, then swallowing tropism granular leukocytes were found 3d post inoculation, swallowed macrophage also was found, the number of dead cells were increased during anaphase, there were virus inside and outside cellular.According to Beijing duck CD4 gene sequence(AF378701) in GeneBank designed, synthesized a specific primer, and then amplificated Cherry Valley Duck and Sheldrake duck CD4 ORF genes.Determinations results of the two sequences were loged on to GeneBank. Accession number of Cherry Valley Duck and Sheldrake duck were FJ527911 and FJ527912 respectively. The two sequences were analyzed by biological software, such as BLAST and DNASTAR software, result showed that DuCD4 ORF the sequence homology among Cherry Valley Duck, Sheldrake duck and Beijing Duck were 99%.