Genome-wide association study of myofiber type composition traits in a yellow-feather broiler population.

Meat quality is a key factor determining the economic viability of the broiler industry, particularly in native broiler breeds. Skeletal muscles contain a mixture of muscle fibers, each possessing unique physicochemical properties; the composition of myofiber types within these muscles is closely linked to meat quality. However, comprehension of the regulatory mechanisms governing this trait remains limited.

METTL16 inhibits differentiation and promotes proliferation and slow myofibers formation in chicken myoblasts.

N6-methyladenosine (m6A) plays a crucial regulatory role in muscle growth and development. In our previous studies, we identified a m6A methyltransferase, Methyltransferase like 16 (METTL16), which is associated with chicken muscle development and muscle fiber type conversion. To further understand the regulatory role of METTL16 in chicken muscle function, we analyzed its expression in muscle tissues with different myofiber type compositions and in chicken primary myoblasts (CPMs) at various stages.

Dynamic Transcriptome Profile Analysis of Mechanisms Related to Melanin Deposition in Chicken Muscle Development.

The pectoral muscle is an important component of skeletal muscle. The blackness of pectoral muscles can directly affect the economic value of black-boned chickens. Although the genes associated with melanogenesis in mammals and birds have been thoroughly investigated, only little is known about the key genes involved in muscle hyperpigmentation during embryonic development.

Molecular Regulatory Mechanisms in Chicken Feather Follicle Morphogenesis.

In China, the sale of freshly slaughtered chickens is becoming increasingly popular in comparison with that of live chickens, and due to this emerging trend, the skin and feather follicle traits of yellow-feathered broilers have attracted a great deal of research attention. The feather follicle originates from the interaction between the epidermis and dermis in the early embryonic stage. Feather follicle morphogenesis is regulated by the Wnt, ectodysplasin (Eda), epidermal growth factor (EGF), fibroblast growth factor (FGF), bone morphogenetic protein (BMP), sonic hedgehog (Shh), Notch, and other signaling pathways that exist in epithelial and mesenchymal cells.

Transcriptome sequencing analysis of the role of miR-499-5p and in chicken skeletal myofiber specification.

MicroRNAs (miRNAs) might play critical roles in skeletal myofiber specification. In a previous study, we found that chicken miR-499-5p is specifically expressed in slow-twitch muscle and that its potential target gene is . In this study, we performed RNA sequencing to investigate the effects of and miR-499-5p on the modulation and regulation of chicken muscle fiber type and its regulatory mechanism.

Population Structure and Genetic Diversity of Seven Chinese Indigenous Chicken Populations in Guizhou Province.

To investigate the population structure and genetic diversity of indigenous chicken breeds in Guizhou, a total of 150 individual samples were collected from 12 breeds, including seven local chicken breeds in Guizhou Province, three Chinese native breeds found in other provinces, and two commercial breeds. The genotype datasets were obtained using a 50K single nucleotide polymorphism array method, and then a series of population analyses were performed. The obtained population parameters and linkage disequilibrium decay indicated a higher degree of genetic diversity in Guizhou chickens than in commercial breeds.

Deep sequencing microRNA profiles associated with wooden breast in commercial broilers.

Wooden breast (WB) is a muscle disorder affecting modern commercial broiler chickens that leads to a palpable firm pectoralis major muscle and causes severe reduction in meat quality, resulting in substantial economic losses for the poultry industry. Most studies have focused on the regulatory mechanisms underlying this defect with respect to the gene and protein expression levels as well as the levels of metabolites. MicroRNAs (miRNAs) play critical roles in human muscular disorders, such as the Duchenne muscular dystrophy, by regulating the muscle regeneration or fibrosis processes.

Analysis of potential regulatory LncRNAs and CircRNAs in the oxidative myofiber and glycolytic myofiber of chickens.

SART and PMM are mainly composed of oxidative myofibers and glycolytic myofibers, respectively, and myofiber types profoundly influence postnatal muscle growth and meat quality. SART and PMM are composed of lncRNAs and circRNAs that participate in myofiber type regulation. To elucidate the regulatory mechanism of myofiber type, lncRNA and circRNA sequencing was used to systematically compare the transcriptomes of the SART and PMM of Chinese female Qingyuan partridge chickens at their marketing age.

Identifying Signatures of Selection Related to Comb Development.

The aim of this study was to identify genes involved in comb development to provide insights into the molecular mechanism of chickens' comb formation. Fixation index (F) and average number of base differences () of males with large and small combs were calculated based on whole-genome resequencing data. Chromosome regions with larger F values and smaller were considered candidate selection regions.

miRNA-mRNA network regulation in the skeletal muscle fiber phenotype of chickens revealed by integrated analysis of miRNAome and transcriptome.

Skeletal muscle fibers are primarily categorized into oxidative and glycolytic fibers, and the ratios of different myofiber types are important factors in determining livestock meat quality. However, the molecular mechanism for determining muscle fiber types in chickens was hardly understood. In this study, we used RNA sequencing to systematically compare mRNA and microRNA transcriptomes of the oxidative muscle sartorius (SART) and glycolytic muscle pectoralis major (PMM) of Chinese Qingyuan partridge chickens.

A gene co-expression network analysis of the candidate genes and molecular pathways associated with feather follicle traits of chicken skin.

Back and thigh skin of chickens showed significant differences in the thickness and the feather follicle density and size, which are important traits for slaughtered chickens' appearance. In the present study, global gene expression profiling was conducted in the back and thigh skin of chickens using Microarray technology. The results showed that 676 genes were differentially expressed between back and thigh skin.

Monitoring conservation effects on a Chinese indigenous chicken breed using major histocompatibility complex B-G gene and DNA Barcodes.

Objective: We report monitoring conservation effect for a Chinese indigenous chicken (Langshan) breed using major histocompatibility complex (MHC) and DNA barcords.

Methods: The full length of MHC B-G gene and mitochondrial cytochrome oxidase I (COI) gene in generations 0, 5, 10, 15, 16, and 17 was measured using re-sequencing and sequencing procedures, respectively.

Results: There were 292 single nucleotide polymorphisms of MHC B-G gene identified in six generations.

Molecular Cloning, Characterization, and Temporal Expression Profile of Troponin I Type 1 (TNNI1) Gene in Skeletal Muscle During Early Development of Gaoyou Duck (Anas Platyrhynchos Domestica).

TNNI1 encodes the slow skeletal muscle isoform of troponin I. In the present study, the basic characteristic and expressing profile of the TNNI1 gene was first explored in Gaoyou ducks. Full-length TNNI1 cDNA of Gaoyou duck was obtained using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE).

Identification of molecular pathways and candidate genes associated with cocks' comb size trait by genome-wide transcriptome analysis.

The comb of the male is an important secondary sexual characteristic. Although quantitative trait loci (QTLs) related to comb size have been identified, molecular mechanisms underlying this trait remain mostly unknown. In this study, RNA sequencing (RNA-seq) was employed to compare whole transcriptomic differences between two groups of Partridge Shank chickens that are divergent in comb sizes.

Oxidative and glycolytic skeletal muscles show marked differences in gene expression profile in Chinese Qingyuan partridge chickens.

Oxidative and glycolytic myofibers have different structures and metabolic characteristics and their ratios are important in determining poultry meat quality. However, the molecular mechanisms underlying their differences are unclear. In this study, global gene expression profiling was conducted in oxidative skeletal muscle (obtained from the soleus, or SOL) and glycolytic skeletal muscle (obtained from the extensor digitorum longus, or EDL) of Chinese Qingyuan partridge chickens, using the Agilent Chicken Gene Expression Chip.

Expression of Lipid Metabolism-Associated Genes in Male and Female White Feather Chicken.

Differential lipid metabolic requirements of sexually-mature males and females may influence the regulation of lipid metabolism-associated genes and hence the content of adipose tissue. We measured the expression of eight lipid metabolism-associated genes (fatty acid synthase, ; acylglycerol- 3- phosphate O-acyltransferase 9, ; peroxisomal proliferator-activated receptor ; lipoprotein lipase, ; carnitine palmitoyl transferase 1 A, ; carnitine palmitoyl transferase 1 B, ; acyl-COA dehydrogenase long chain, ; monoglyceride lipase, ) in eight tissues (hypothalamus, HYP; liver; heart; pectoralis major muscle, PM; gastrocnemius muscle, GAS; abdominal fat, AF; clavicular fat, CF; subcutaneous fat, SF) of five male and five female white feather chickens using real time PCR at 217 d (when the females were at peak egg production). There were no difference between sexes, nor were there sex by tissue interactions for and .

Residues, Sources and Potential Biological Risk of Organochlorine Pesticides in Surface Sediments of Qiandao Lake, China.

Sediment samples were analyzed to comprehensively characterize the concentrations, distribution, possible sources and potential biological risk of organochlorine pesticides in Qiandao Lake, China. Concentrations of sumHCH and sumDDT in sediments ranged from 0.03 to 5.

Asymmetries in chickens from lines selected and relaxed for high or low antibody titers to sheep red blood cells.

Wattle length, width, and area were measured to classify bilateral asymmetries in four lines of chickens. The lines were the S26 generation of White Leghorns selected for high (HAS) or low (LAS) response to sheep red blood cells and sublines in which selection had been relaxed for three generations (high antibody relaxed [HAR] and low antibody relaxed [LAR]). Antibody titers (AB) were greater for HAS than for HAR with both greater than for LAS and LAR which while different for males did not differ for females.

Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.

Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.

Hydrolysis and soil sorption of insecticide pyraclofos.

The hydrolysis of the insecticide pyraclofos in buffered solutions at pH 5.0, 7.0 and 9.

Separation and aquatic toxicity of enantiomers of the pyrethroid insecticide lambda-cyhalothrin.

Chiral pollutants are receiving growing environmental concern due to differential biological activities of their enantiomers. In the present study, enantiomeric separation of the pyrethroid insecticide lambda-cyhalothrin (LCT) was investigated by high-performance liquid chromatography (HPLC) using the columns of Chiralpak AD (amylase tris[3,5-dimethyl-phenyl carbamate]), Chiralpak AS (amylase tris[(S)-1-phenyl carbamate]), Chiralcel OD (cellulose tris[3,5-dimethylphenyl carbamate]), and Chiralcel OJ (cellulose tris[4-methyl benzoate]) with different chiral stationary phases. The differential toxicities of the enantiomers in aquatic systems were evaluated using the acute zebrafish (Danio rerio) toxicity test and the zebrafish embryo test.

[Molecular genetic diversity of Fujian domestic duck breeds].

By using 28 micro-satellite markers with better polymorphism, this paper studied the genetic diversity of four Fujian provincial domestic duck breeds Jinding, Putian black, Liancheng white, and Shanma. According to the alleles frequencies, the polymorphic information content, average heterozygosity, anaqular genetic distance (DA) and Nei' s standard genetic distance (DS) for each breed were calculated. Based on DA and DS, four dendrograms were obtained by neighbor-joining (NJ) and UPGMA methods.