Metabolites from intestinal microbes modulate the mucosal immune system by regulating the polarization and expansion of T cells. Whether the microbial metabolites influence macrophage polarization, however, is poorly understood. Here, we show that the large bowel microbial fermentation product, butyrate, facilitates M2 macrophage polarization, in vitro and in vivo. The supernatant from butyrate-treated M2 macrophage increased the migration and enhanced the wound closure rate of MLE-12 cells. Butyrate attenuated intestinal inflammation in mice with dextran sulfate sodium (DSS)-induced colitis, with a significant increase in colonic expression of the M2 macrophage-associated protein, Arg1. M2 macrophage treated with butyrate, had increased activation of the H3K9/STAT6 signaling pathway, suggesting a mechanism for butyrate facilitated M2 macrophage polarization. Collectively, our study indicated that commensal microbe-derived butyrate is a novel activator of STAT6-mediated transcription through H3K9 acetylation driving M2 macrophage polarization, and delineated new insights into the immune interplay underlying inflammatory bowel disease.

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BackgroundIn China, consumers often prefer indigenous broiler chickens over commercial breeds, as they have characteristic meat qualities requested within traditional culinary customs. However, the growth-rate of these indigenous breeds is slower than that of the commercial broilers, which means they have not yet reached their full economic value. Therefore, combining the valuable meat quality of the native chickens with the efficiency of the commercial broilers is of interest. In this study, we generated an F2 intercross between the slow growing native broiler breed, Huiyang Beard chicken, and the fast growing commercial broiler breed, High Quality chicken Line A, and used it to map loci explaining the difference in growth rate between these breeds.ResultsA genome scan to identify main-effect loci affecting 24 growth-related traits revealed nine distinct QTL on six chromosomes. Many QTL were pleiotropic and conformed to the correlation patterns observed between phenotypes. Most of the mapped QTL were found in locations where growth QTL have been reported in other populations, although the effects were greater in this population. A genome scan for pairs of interacting loci identified a number of additional QTL in 10 other genomic regions. The epistatic pairs explained 6–8% of the residual phenotypic variance. Seven of the 10 epistatic QTL mapped in regions containing candidate genes in the ubiquitin mediated proteolysis pathway, suggesting the importance of this pathway in the regulation of growth in this chicken population.ConclusionsThe main-effect QTL detected using a standard one-dimensional genome scan accounted for a significant fraction of the observed phenotypic variance in this population. Furthermore, genes in known pathways present interesting candidates for further exploration. This study has thus located several QTL regions as promising candidates for further study, which will increase our understanding of the genetic mechanisms underlying growth-related traits in chickens.

BackgroundThe nephropathogenic avian infectious bronchitis (IB) caused unprecedented economic losses to the commercial chicken industry of China in 2008-2009. To investigate the prevalence of nephropathogenic IB in China, eighty IBV isolates from different provinces during 2008-2009 were identified by dwarf embryo test and RT-PCR.ResultsThe strains were mostly isolated in winter and spring with a wide age range of IB outbreaks, from 4 to 69 days. By the virus recovery trials, 70/80 of the strains resulted in the deaths or distresses of birds from nephritis. To learn more about the molecular evolutionary characteristics of the circulating field strains, the coding region of major spike 1 (S1) protein gene of these strains was RT-PCR amplified and sequenced. Compared to the published representative strains, nucleotides and amino acids sequence analysis indicated that the S1 genes of these strains and the reference strains displayed homologies ranging from 75.1% to 99.8% and from 73.1% to 99.8% respectively. S1 protein of the major pandemic strains contained 540 or 542 amino acids with the cleavage site of HRRRR or RRFRR. Phylogenetic analysis revealed that recent field isolates of IBV in China were mostly belonged to A2-branch (QXIBV-branch) and HN08-branch, only one isolate was belonged to Gray-branch and M41-branch respectively. Most of the 80 strains showed evolutionarily distant from vaccine strains.ConclusionsThe results of this study suggested that nephropathogenic IBVs were mainly A2-like strains in China during 2008-2009.

Gamecock chickens are one of the earliest recorded birds in China, and have accumulated some unique morphological and behavioral signatures such as large body size, muscularity and aggressive behavior, whereby being excellent breeding materials and a good model for studying bird muscular development and behavior. In this study, we sequenced 126 chicken genomes from 19 populations, including four commercial chicken breeds that are commonly farmed in China, 13 nationwide Chinese typical indigenous chicken breeds (including two Chinese gamecock breeds), one red jungle fowl from Guangxi Province of China and three gamecock chickens from Laos. Combined with 31 published chicken genomes from three populations, a comparative genomics analysis was performed across 157 chickens. We found a severe confounding effect on potential cold adaptation exerted by introgression from commercial chickens into Chinese indigenous chickens, and argued that the genetic introgression from commercial chickens into indigenous chickens should be seriously considered for identifying selection footprint in indigenous chickens. LX gamecock chickens might have played a core role in recent breeding and conservation of other Chinese gamecock chickens. Importantly, AGMO ( Alkylglycerol monooxygenase ) and CPZ ( Carboxypeptidase Z ) might be crucial for determining the behavioral pattern of gamecock chickens, while ISPD ( Isoprenoid synthase domain containing ) might be essential for the muscularity of gamecock chickens. Our results can further the understanding of the evolution of Chinese gamecock chickens, especially the genetic basis of gamecock chickens revealed here was valuable for us to better understand the mechanisms underlying the behavioral pattern and the muscular development in chicken.