Differential metabolism -associated gene expression of duck pancreatic cells in response to two subtype s of duck hepatitis A virus type 1

Background: Duck hepatitis A virus type 1 (DHAV-1) causes a highly contagious disease in domestic ducklings, which is traditionally characterized by lesions in the liver and rarely in the pancreas. However, several outbreaks of DHAV-1, which were characterized by yellow coloration and hemorrhage in pancreatic tissues, have occurred in China. The causative agent was named as pancreatitis-type DHAV-1. Genomic sequencing indicated variation rates of 3.4-6.5% in the genome of the pancreatitis-type DHAV-1 compared with those of the classical type DHAV-1. The antigenic relationship between the pancreatitis-type DHAV-1 and classical type DHAV-1 indicated large variation. However, the mechanism involved in infection of the pancreatitis-type DHAV-1 is still unclear. Results: In the present study, transcriptome analysis of duck pancreas infected with classical type DHAV-1 and pancreatitis-type DHAV-1 was carried out. Following deep sequencing with Illumina-Solexa, a total of 53.9 Gb clean data were obtained from the cDNA library of the pancreas and a total of 29,597 unigenes with an average length of 993.43 bp were generated following de novo sequence assembly. The expression levels of D-3-phosphoglyceratedehydrogenase, phosphoserine aminotransferase, phosphoserine phosphatase, which are involved in glycine, serine and threonine metabolism pathway, were significantly downregulated in the pancreatitis-type DHAV-1-infected group compared with those of the classical type DHAV-1-infected group.Conclusion: These findings provide information regarding differential expression levels of metabolism-associated genes between pancreatitis-type DHAV-1 and classical type DHAV-1, indicating that intensive metabolism disorders may contribute to different subtypes of DHAV-1-infection.