Project description:We carried out a comparative genomic analysis of 48 avian species to identify avian-specific highly conserved elements (ASHCEs). We performed genome-wide chromatin immunoprecipitation sequencing (ChIP-seq) for three enhancer-associated histone modifications (H3K4me1, H3K27ac, H3K27me3), to investigate dynamic regulatory roles of ASHCEs in chicken development. We found that all three enhancer-associated histone marks are enriched in ASHCEs compared to the whole genome background.
Project description:We report the genome-wide DNA methylation mapping of chicken by methylated DNA immunoprecipitation following by highthroughput sequencing, and the gene expression profile of chicken by RNA-seq. For meDIP-seq, about 17,202,074 to 27,501,760 reads were generated for the tissue and liver tissues of the red jungle fowl and the avian broiler each. We found that compared with the red jungle fowl, DNA methylation in muscle tissue of the avian broiler, showed dramatically decline on a genome-wide scale. Furthermore, the length of the highly methylated regions (HMRs) has become shorter in the avian broiler, which has suffered intense artificial selection. In addition to the global changes in DNA methylation, transcriptome-wide analysis of the two breeds of chicken revealed that the patterns of gene expression in the domestic chicken have undergone a specific bias towards a pattern that is more suited to human-made environments with variable expression in certain gene functions, such as immune response and fatty acid metabolism. Our results demonstrated a potential role of epigenetic modification in animal domestication besides the genetic variations. Examination of whole genome DNA methylation status in liver and muscle of two chicken breeds.
Project description:We infected DF-1 cells with avian reovirus, and then used high-throughput sequencing to detect changes in miRNA expression profiles. This research provides a more comprehensive understanding of the interaction between viruses and host cells
Project description:Avian beaks show extreme species-specific variability in morphology, though they develop from the same primordial structures. In both humans and birds, cranial neural crest cells are the primary source of mesenchyme for the frontonasal prominence; previous work has shown that these cells contain molecular information that regulate species-specific facial variation. To determine the molecular basis of avian craniofacial patterning, we have used Next-Generation sequencing to profile all 20-40nt microRNAs from micro-dissected cranial neural crest cells from the frontonasal prominence of three bird species (chickens, quails, and ducks). Samples for each species were isolated at two developmental stages, before (Hamilton Hamburger stage [HH] 20) and after (HH25) morphological distinctions between the species are evident.
Project description:Sanhong Liu, Shigui Ruan & Xinan Zhang. Nonlinear dynamics of avian influenza epidemic models. Mathematical Biosciences 283 (2017).
Avian influenza is a zoonotic disease caused by the transmission of the avian influenza A virus, such as H5N1 and H7N9, from birds to humans. The avian influenza A H5N1 virus has caused more than 500 human infections worldwide with nearly a 60% death rate since it was first reported in Hong Kong in 1997. The four outbreaks of the avian influenza A H7N9 in China from March 2013 to June 2016 have resulted in 580 human cases including 202 deaths with a death rate of nearly 35%. In this paper, we construct two avian influenza bird-to-human transmission models with different growth laws of the avian population, one with logistic growth and the other with Allee effect, and analyze their dynamical behavior. We obtain a threshold value for the prevalence of avian influenza and investigate the local or global asymptotical stability of each equilibrium of these systems by using linear analysis technique or combining Liapunov function method and LaSalle's invariance principle, respectively. Moreover, we give necessary and sufficient conditions for the occurrence of periodic solutions in the avian influenza system with Allee effect of the avian population. Numerical simulations are also presented to illustrate the theoretical results.