Evaluation via Supervised Machine Learning of the Broiler Pectoralis Major and Liver Transcriptome in Association With the Muscle Myopathy Wooden Breast.

The muscle myopathy wooden breast (WB) has recently appeared in broiler production and has a negative impact on meat quality. WB is described as hard/firm consistency found within the pectoralis major (PM). In the present study, we use machine learning from our PM and liver transcriptome dataset to capture the complex relationships that are not typically revealed by traditional statistical methods.

Effects of acute and chronic heat stress on the performance, egg quality, body temperature, and blood gas parameters of laying hens.

The goal of this experiment was to measure the physiological response of individual laying hens exposed to heat stress (HS). Performance, egg quality, body temperature (BT), and blood chemistry of laying hens were individually recorded before and after various intervals of daily cyclic HS. In total, 407 18-week-old W-36 parent-line laying hens (Hy-Line International, Dallas Center, IA) were housed individually in battery cages.

Genetic analysis of production, physiological, and egg quality traits in heat-challenged commercial white egg-laying hens using 600k SNP array data.

Background: Heat stress negatively affects the welfare and production of chickens. High ambient temperature is considered one of the most ubiquitous abiotic environmental challenges to laying hens around the world. In this study, we recorded several production traits, feed intake, body weight, digestibility, and egg quality of 400 commercial white egg-laying hens before and during a 4-week heat treatment.

Natural Selection Footprints Among African Chicken Breeds and Village Ecotypes.

Natural selection is likely a major factor in shaping genomic variation of the African indigenous rural chicken, driving the development of genetic footprints. Selection footprints are expected to be associated with adaptation to locally prevailing environmental stressors, which may include diverse factors as high altitude, disease resistance, poor nutrition, oxidative and heat stresses. To determine the existence of a selection footprint, 268 birds were randomly sampled from three indigenous ecotypes from East Africa (Rwanda and Uganda) and North Africa (Baladi), and two registered Egyptian breeds (Dandarawi and Fayoumi).

Genomic Comparison of Indigenous African and Northern European Chickens Reveals Putative Mechanisms of Stress Tolerance Related to Environmental Selection Pressure.

Global climate change is increasing the magnitude of environmental stressors, such as temperature, pathogens, and drought, that limit the survivability and sustainability of livestock production. Poultry production and its expansion is dependent upon robust animals that are able to cope with stressors in multiple environments. Understanding the genetic strategies that indigenous, noncommercial breeds have evolved to survive in their environment could help to elucidate molecular mechanisms underlying biological traits of environmental adaptation.

Unique genetic responses revealed in RNA-seq of the spleen of chickens stimulated with lipopolysaccharide and short-term heat.

Climate change and disease have large negative impacts on poultry production, but little is known about the interactions of responses to these stressors in chickens. Fayoumi (heat and disease resistant) and broiler (heat and disease susceptible) chicken lines were stimulated at 22 days of age, using a 2x2x2 factorial design including: breed (Fayoumi or broiler), inflammatory stimulus (lipopolysaccharide (LPS) or saline), and temperature (35°C or 25°C). Transcriptional changes in spleens were analyzed using RNA-sequencing on the Illumina HiSeq 2500.

Identification of quantitative trait loci for body temperature, body weight, breast yield, and digestibility in an advanced intercross line of chickens under heat stress.

Background: Losses in poultry production due to heat stress have considerable negative economic consequences. Previous studies in poultry have elucidated a genetic influence on response to heat. Using a unique chicken genetic resource, we identified genomic regions associated with body temperature (BT), body weight (BW), breast yield, and digestibility measured during heat stress.

Transcriptome response to heat stress in a chicken hepatocellular carcinoma cell line.

Heat stress triggers an evolutionarily conserved set of responses in cells. The transcriptome responds to hyperthermia by altering expression of genes to adapt the cell or organism to survive the heat challenge. RNA-seq technology allows rapid identification of environmentally responsive genes on a large scale.

Transcriptome analysis of post-hatch breast muscle in legacy and modern broiler chickens reveals enrichment of several regulators of myogenic growth.

Agriculture provides excellent model systems for understanding how selective pressure, as applied by humans, can affect the genomes of plants and animals. One such system is modern poultry breeding in which intensive genetic selection has been applied for meat production in the domesticated chicken. As a result, modern meat-type chickens (broilers) exhibit enhanced growth, especially of the skeletal muscle, relative to their legacy counterparts.

A genomic duplication is associated with ectopic eomesodermin expression in the embryonic chicken comb and two duplex-comb phenotypes.

Duplex-comb (D) is one of three major loci affecting comb morphology in the domestic chicken. Here we show that the two Duplex-comb alleles, V-shaped (D*V) and Buttercup (D*C), are both associated with a 20 Kb tandem duplication containing several conserved putative regulatory elements located 200 Kb upstream of the eomesodermin gene (EOMES). EOMES is a T-box transcription factor that is involved in mesoderm specification during gastrulation.

RNA-seq analysis of broiler liver transcriptome reveals novel responses to high ambient temperature.

Background: In broilers, high ambient temperature can result in reduced feed consumption, digestive inefficiency, impaired metabolism, and even death. The broiler sector of the U.S.

Genetic variation within the Mx gene of commercially selected chicken lines reveals multiple haplotypes, recombination and a protein under selection pressure.

The Mx protein is one of the best-characterized interferon-stimulated antiviral mediators. Mx homologs have been identified in most vertebrates examined; however, their location within the cell, their level of activity, and the viruses they inhibit vary widely. Recent studies have demonstrated multiple Mx alleles in chickens and some reports have suggested a specific variant (S631N) within exon 14 confers antiviral activity.

A cis-regulatory mutation of PDSS2 causes silky-feather in chickens.

Silky-feather has been selected and fixed in some breeds due to its unique appearance. This phenotype is caused by a single recessive gene (hookless, h). Here we map the silky-feather locus to chromosome 3 by linkage analysis and subsequently fine-map it to an 18.

Cell walls of Saccharomyces cerevisiae differentially modulated innate immunity and glucose metabolism during late systemic inflammation.

Background: Salmonella causes acute systemic inflammation by using its virulence factors to invade the intestinal epithelium. But, prolonged inflammation may provoke severe body catabolism and immunological diseases. Salmonella has become more life-threatening due to emergence of multiple-antibiotic resistant strains.

A complex genomic rearrangement involving the endothelin 3 locus causes dermal hyperpigmentation in the chicken.

Dermal hyperpigmentation or Fibromelanosis (FM) is one of the few examples of skin pigmentation phenotypes in the chicken, where most other pigmentation variants influence feather color and patterning. The Silkie chicken is the most widespread and well-studied breed displaying this phenotype. The presence of the dominant FM allele results in extensive pigmentation of the dermal layer of skin and the majority of internal connective tissue.

Genomic regions associated with dermal hyperpigmentation, polydactyly and other morphological traits in the Silkie chicken.

The Silkie chicken has been a model of melanoctye precursor and neural crest cell migration and proliferation in the developing embryo due to its extensive hyperpigmentation of dermal and connective tissues. Although previous studies have focused on the distribution and structure of the Silkie's pigment or the general mechanisms by which this phenotype presents itself, the causal genetic variants have not been identified. Classical breeding experiments have determined this trait to be controlled by 2 interacting genes, the sex-linked inhibitor of dermal melanin (Id) and autosomal fibromelanosis (Fm) genes.

Dietary iron deficiency compromises normal development of elastic fibers in the aorta and lungs of chicks.

Elastic fibers play a key role in the structure and function of numerous organs that require elasticity. Elastogenesis is a complex process in which cells first produce a microfibrillar scaffold, composed of numerous structural proteins, upon which tropoelastin assembles to be cross-linked into polymeric elastin. Recently, it was demonstrated that low concentrations of free iron upregulate elastin gene expression in cultured fibroblasts.

CA125 expression in spontaneous ovarian adenocarcinomas from laying hens.

Objective: Currently, there is not a fully characterized model for human ovarian cancer; however, 2- to 4-year-old laying hens spontaneously develop ovarian tumors. CA125 expression is a hallmark of ovarian cancer in women. The major objective of this study was to characterize the in vitro growth of avian ovarian tumor cells, and CA125 expression in avian ovarian tumors.

Meeting patients' needs in secure forensic psychiatric units.

The authors have developed a security needs assessment profile designed to match the service provided in secure, forensic psychiatric units more accurately with the needs of individual patients. They are carrying out an 18-month survey of all secure units in England and are seeking participants to help refine the profile, gain more understanding of what is provided throughout the country, and assess the views of other clinicians and managers.