Transcriptome dynamics reveals the resilience of liver and spleen during avian pathogenic Escherichia coli challenge
In this study, chicken pectoral muscle injection of Escherichia coli O18 were used as a systemic infection model to detect the changes in organ weight, blood biochemical parameters, and histopathology during infection and to profile transcriptome dynamics in the liver and spleen at different stages of infection. It was shown that Escherichia coli O18 induced a severe immune response in chickens at 2 dpi, whereas the indices gradually recovered at 5 dpi. The liver differential express genes (DEGs) were mainly enriched in the C-type lectin receptor signaling pathway , suggesting that APEC infection activates immune response-related pathways, and down-regulated genes were enriched in the DNA replication pathway, suggesting that APEC infection inhibits cell proliferation-related pathways. Surprisingly, 5dpi showed opposite gene expression results, suggesting that the host may begin to control APEC pathogenicity. Spleen transcriptomics showed similar dynamic expression results, with DEGs enriched mainly in the C-type lectin receptor signaling pathway and MAPK signaling pathway pathways. In this study, we elucidated the dynamic expression changes of mRNA levels in chicken livers and spleens after APEC infection and identified candidate genes during dynamic host infection of APEC. Overall design: One hundred chickens were divided into Avian Pathogenic Escherichia coli infected and uninfected groups, and liver and spleen samples were collected 2 and 5 days after infection, with five replicates in each group for RNA-seq sequencing.