Project description:Swine streptococcosis has caused great economic loss in the swine industry, and the major pathogen responsible for this disease is Streptococcus Suis serotype 2 (SS2). Disease resistance breeding is a fundamental way of resolving this problem. With the development of GWAS and transcriptomic microarray technology, we now have powerful research tools to identify SS2 resistance genes. In this research, we generated an F2 generation of SS2 resistant C57BL/6 and SS2 susceptive A/J mice. With the F2 generation of these two mice strains and GWAS analysis, we identified 286 significant mouse genome SNPs sites associated with the SS2 resistance trait. Gene expression profiles for C57BL/6 and A/J were analyzed under SS2 infection pressure by microarray. In total, 251 differentially expressed genes were identified between these two mouse strains during SS2 infection. After combining the GWAS and gene expression profile data, we located two genes that were significantly associated with SS2 resistance, which were the UBA domain containing 1 gene (Ubac1) and Epsin 1 gene (Epn 1). GO classification and over-representation analysis revealed nine up-regulated related to immune function, which could potentially be involved in the C57BL/6 SS2 resistance trait. This is the first study to use both SNP chip and gene express profile chip for SS2 resistance gene identification in mouse, and these results will contribute to Swine SS2 resistance breeding.
Project description:Mycoplasma hyopneumoniae, the causative agent of swine enzootic pneumonia, colonizes the cilia of swine lungs, causing ciliostasis and cell death. Mycoplasma hyopneumoniae is a component of the porcine respiratory disease complex (PRDC) and is especially problematic for the finishing swine industry, causing the loss of hundreds of millions of dollars in farm revenues worldwide. For successful infection, M. hyopneumoniae must effectively resist oxidative stresses due to the release of oxidative compounds from neutrophils and macrophages during the host’s immune response. However, the mechanism M. hyopneumoniae uses to avert the host response is still unclear. To gain a better understanding of the transcriptional responses of M. hyopneumoniae under oxidative stress, cultures were grown to early exponential phase and exposed to 0.5% percent hydrogen peroxide for 15 minutes. RNA samples from these cultures were collected and compared to RNA samples from control cultures using two-color PCR-based M. hyopneumoniae microarrays. This study revealed significant down-regulation of important glycolytic pathway genes and gene transcription proteins, as well as a protein known to activate oxidative stressor cascades in neutrophils. This study has also contained significantly differentially expressed genes common to other environmental stress responses, and merits further study of universal stress response genes of M. hyopneumoniae. Keywords: Mycoplasma hyopneumoniae, RNA microarray
Project description:Swine H1N1 influenza virus and streptococcus suis serotype 2 (SS2) are two important contributors to the porcine respiratory disease complex, which have significant economic impacts. Clinically, swine influenza virus and swine streptococcus suis co-infection is common, which will increase the mortality. However, the pathogenesis of the co-infection remains largely unkown. To explore it, gene expression profiling was to performed to detect comprehensive analysis of the global host response induced by H1N1 virus infection alone, SS2 infection alone, H1N1-SS2 co-infection and PBS control.
Project description:Streptococcus suis serotype 2 (SS2), a major swine pathogen and an emerging zoonotic agent, has greatly challenged global public health. Systematical information about host immune response to the infection is important for understanding the molecular mechanism of diseases. Here, we investigated the global expression changes in spleen following SS2 infection using the Affymetrix Porcine Genechip. Our findings indicate previously unrecognized gene transcription changes in case of SS infection in vivo. Our data should provide new clues for immune response in mammals and identification of candidate genes related to SS resistance.
