Project description:Chromosomal segmental copy number variation (CNV) has been recently recognized as a very important source of genetic variability. Some CNV loci involve genes or conserved regulatory regions. Compelling evidence indicates that CNVs impact genome functions. The chicken is a very important farm animal species which has also served as model animal for biological and biomedical research for hundreds of years. A map of CNVs in chickens could facilitate the identification of chromosome regions that segregate for important agricultural and disease phenotypes. NimbleGen 385k whole genome tiling arrays were used to map CNVs in the chicken. This study has identified 96 CNVs in three lines of chickens (broiler, Leghorn and Rhode Island red). These CNVs encompass 16 Mb (1.3%) of the chicken genome. Twenty six CNVs were found in two or more animals. Smaller sized CNVs mostly affect none coding sequences while larger CNV regions involve genes, for example prolactin receptor, aldose reductase and zinc finger proteins, suggesting chicken CNVs potentially affect agricultural or disease related traits.
Project description:Purpose: To identify the key regulatory genes and pathways involved in chicken high egg productivon in HPG axis. Methods: A total of 856 Chinese Luhua chicken was raised in poultry breeding farm of Sichuan Agricultural University, the highest two hundred and the lowest two hundred chicken egg production were considered as high egg production (HEP) and low egg production (LEP) according to the total egg number at 300 days of age, respectively, integrated with RNA-seq sequencing of samples of HPG axis (hypothalamus, pituitary gland and ovary) from three HEP and three LEP chickens at 300 days of age. Results: A total 86.7 Gb RNA-seq sequences were generated, and with each library averaged 5.1 Gb. Conclusions: These important data might improve our understanding of reproductive biology of Luhua chicken by providing comprehensive gene expression information at transcriptional level. We indicate that our approach will contribute to the isolation of effective molecular markers that can be used in genetic breeding programs in Chinese domestic Luhua chicken.
Project description:<p>The study of antimicrobial resistance (AMR) in infectious diarrhea has generally been limited to cultivation, antimicrobial susceptibility testing and targeted PCR assays. When individual strains of significance are identified, whole genome shotgun (WGS) sequencing of important clones and clades is performed. Genes that encode resistance to antibiotics have been detected in environmental, insect, human and animal metagenomes and are known as "resistomes". While metagenomic datasets have been mined to characterize the healthy human gut resistome in the Human Microbiome Project and MetaHIT and in a Yanomani Amerindian cohort, directed metagenomic sequencing has not been used to examine the epidemiology of AMR. Especially in developing countries where sanitation is poor, diarrhea and enteric pathogens likely serve to disseminate antibiotic resistance elements of clinical significance. Unregulated use of antibiotics further exacerbates the problem by selection for acquisition of resistance. This is exemplified by recent reports of multiple antibiotic resistance in Shigella strains in India, in Escherichia coli in India and Pakistan, and in nontyphoidal Salmonella (NTS) in South-East Asia. We propose to use deep metagenomic sequencing and genome level assembly to study the epidemiology of AMR in stools of children suffering from diarrhea. Here the epidemiology component will be surveillance and analysis of the microbial composition (to the bacterial species/strain level where possible) and its constituent antimicrobial resistance genetic elements (such as plasmids, integrons, transposons and other mobile genetic elements, or MGEs) in samples from a cohort where diarrhea is prevalent and antibiotic exposure is endemic. The goal will be to assess whether consortia of specific mobile antimicrobial resistance elements associate with species/strains and whether their presence is enhanced or amplified in diarrheal microbiomes and in the presence of antibiotic exposure. This work could potentially identify clonal complexes of organisms and MGEs with enhanced resistance and the potential to transfer this resistance to other enteric pathogens.</p> <p>We have performed WGS, metagenomic assembly and gene/protein mapping to examine and characterize the types of AMR genes and transfer elements (transposons, integrons, bacteriophage, plasmids) and their distribution in bacterial species and strains assembled from DNA isolated from diarrheal and non-diarrheal stools. The samples were acquired from a cohort of pediatric patients and controls from Colombia, South America where antibiotic use is prevalent. As a control, the distribution and abundance of AMR genes can be compared to published studies where resistome gene lists from healthy cohort sequences were compiled. Our approach is more epidemiologic in nature, as we plan to identify and catalogue antimicrobial elements on MGEs capable of spread through a local population and further we will, where possible, link mobile antimicrobial resistance elements with specific strains within the population.</p>
| phs001260 | dbGaP
Project description:Genome sequence of clinical tet(X4)-positive Escherichia coli strains in China