Project description:In the modern chicken industry, fast-growing broilers have undergone strong artificial selection for muscle growth, which has led to remarkable phenotypic variations compared with slow-growing chickens. However, the molecular mechanism underlying these phenotypes differences remains unknown. In this study, a systematic identification of candidate genes and new pathways related to myofiber development and composition in chicken Soleus muscle has been made using gene expression profiles of two distinct breeds: Qingyuan partridge (QY), a slow-growing Chinese breed possessing high meat quality and Cobb 500 (CB), a commercial fast-growing broiler line. Agilent cDNA microarray analyses were conducted to determine gene expression profiles of soleus and extensor digitorum longus muscle sampled at sexual maturity age of QY (112 d) and CB (42 d).
Project description:Abstract: Atmospheric ammonia is a common problem in poultry industry. High concentrations of aerial ammonia cause great harm to broilers' health and production. For the consideration of human health, the limit exposure concentration of ammonia in houses is set at 25 ppm. Previous reports have shown that 25 ppm is still detrimental to livestock, especially the gastrointestinal tract and respiratory tract, but the negative relationship between ammonia exposure and the tissue of breast muscle of broilers is still unknown. In the present study, 25 ppm ammonia in poultry houses was found to lower slaughter performance and breast yield. Then, high-throughput RNA sequencing was utilized to identify differentially expressed genes in breast muscle of broiler chickens exposed to high (25 ppm) or low (3 ppm) levels of atmospheric ammonia. The transcriptome analysis showed that 163 genes (fold change ≥ 2 or ≤ 0.5; P-value < 0.05) were differentially expressed between Ammonia25 (treatment group) and Ammonia3 (control group), including 96 down-regulated and 67 up-regulated genes. qRT-PCR analysis validated the transcriptomic results of RNA sequencing. Gene Ontology (GO) functional annotation analysis revealed potential genes, processes and pathways with putative involvement in growth and development inhibition of breast muscle in broilers caused by aerial ammonia exposure. This study facilitates understanding of the genetic architecture of the chicken breast muscle transcriptome, and has identified candidate genes for breast muscle response to atmospheric ammonia exposure.
Project description:Abstract: Atmospheric ammonia is a common problem in poultry industry. High concentrations of aerial ammonia cause great harm to broilers' health and production. For the consideration of human health, the limit exposure concentration of ammonia in houses is set at 25 ppm. Previous reports have shown that 25 ppm is still detrimental to livestock, especially the gastrointestinal tract and respiratory tract, but the negative relationship between ammonia exposure and the tissue of breast muscle of broilers is still unknown. In the present study, 25 ppm ammonia in poultry houses was found to lower slaughter performance and breast yield. Then, high-throughput RNA sequencing was utilized to identify differentially expressed genes in breast muscle of broiler chickens exposed to high (25 ppm) or low (3 ppm) levels of atmospheric ammonia. The transcriptome analysis showed that 163 genes (fold change â?¥ 2 or â?¤ 0.5; P-value < 0.05) were differentially expressed between Ammonia25 (treatment group) and Ammonia3 (control group), including 96 down-regulated and 67 up-regulated genes. qRT-PCR analysis validated the transcriptomic results of RNA sequencing. Gene Ontology (GO) functional annotation analysis revealed potential genes, processes and pathways with putative involvement in growth and development inhibition of breast muscle in broilers caused by aerial ammonia exposure. This study facilitates understanding of the genetic architecture of the chicken breast muscle transcriptome, and has identified candidate genes for breast muscle response to atmospheric ammonia exposure. Breast muscle mRNA profiles of 42-day old Arbor Acres male broilers exposed to 3 ppm (Ammonia3) and 25 ppm (Ammonia25) concentrations of atmospheric ammonia were generated by RNA sequencing, in duplicate, using Illumina HiSeq2000.
Project description:Background: High concentrations of atmospheric ammonia are one of the key environmental stressors affecting broiler production performance, which causes remarkable economic losses as well as potential welfare problems of the broiler industry. Previous reports have demonstrated that high levels of ammonia can alter body fat distribution and meat quality of broilers. However, the molecular mechanisms and metabolic pathways in breast muscle altered by high concentrations of ambient ammonia exposure on broilers are still unknown. Results: This study utilized RNA-Seq to compare the transcriptomes of breast muscles to identify differentially enriched genes in broilers exposed to high or low concentrations of atmospheric ammonia. A total of 267 promising candidate genes were identified by differential expression analysis, among which 67 genes were up-regulated and 189 genes were down-regulated. Bioinformatics analysis suggested that the up and down-regulated genes were involved in the following two categories of cellular pathways and metabolisms: Steroid biosynthesis (gga00100) and peroxisome proliferator-activated receptor (PPAR) signaling pathway (gga03320), which both participate in the lipid metabolism processes. Conclusions: This study suggests that longtime exposure to high concentrations of aerial ammonia can change fat content in breast muscle, meat quality and palatability via altering expression levels of genes participating in important lipid metabolism pathways. This study maybe provides new information that could be used for genetic breeding and nutritional intervention in production practice of broilers industry in the future.
Project description:Domestic chicken has been intensively studied because of its role as an efficient source of lean meat. However, commercial broilers resulting from genetic selection for rapid growth demonstrate detrimental traits, such as excess deposition of abdominal adipose tissue, metabolic disorders, and reduced reproduction. Therefore fast-growing broilers represent “obese” chickens compared to slow-growing egg layers (e.g, Leghorn) or wild strain of meat-type chickens (e.g., Fayoumi). Fayoumi chickens, originating from Egypt, represent a harder stain of chickens, which are more resistant to diseases. Leghorn chickens are the original breed of commercial U.S layers. Both lines were maintained highly inbred by Iowa State University poultry geneticists with an inbreeding coefficient higher than 0.95. Both Fayoumi and Leghorn demonstrated lean phenotype compared to broilers, and these three lines of chickens are genetically distant from each other. In this study, we used affymetrix microarray to profile global gene expression of three distinct genetic lines of chickens to identify functional pathways associated with leanness of domestic chickens.
Project description:Domestic chicken has been intensively studied because of its role as an efficient source of lean meat. However, commercial broilers resulting from genetic selection for rapid growth demonstrate detrimental traits, such as excess deposition of abdominal adipose tissue, metabolic disorders, and reduced reproduction. Therefore fast-growing broilers represent “obese” chickens compared to slow-growing egg layers (e.g, Leghorn) or wild strain of meat-type chickens (e.g., Fayoumi). Fayoumi chickens, originating from Egypt, represent a harder stain of chickens, which are more resistant to diseases. Leghorn chickens are the original breed of commercial U.S layers. Both lines were maintained highly inbred by Iowa State University poultry geneticists with an inbreeding coefficient higher than 0.95. Both Fayoumi and Leghorn demonstrated lean phenotype compared to broilers, and these three lines of chickens are genetically distant from each other.
Project description:In the current study, we expanded our previous work to identify miRNAs implicated in the myogenesis regulation through the comparison of miRNAs transcriptome in skeletal muscle tissues between broilers and layers. To address that, we firstly performed Solexa deep sequencing to profile miRNAs expressed in chicken skeletal muscle tissues. Sequence tags analyses not only enable us to report a group of highly abundant known miRNAs expressed in skeletal muscles but most importantly to identify novel putative chicken miRNAs from skeletal muscle tissue. Further miRNA transcriptome comparison and real-time RT-PCR validation experiments revealed seveal differentially expressed miRNAs between broilers and layers. Examination of miRNA transcriptome in skeletal muscle of two kinds of chickens
Project description:In the current study, we expanded our previous work to identify miRNAs implicated in the myogenesis regulation through the comparison of miRNAs transcriptome in skeletal muscle tissues between broilers and layers. To address that, we firstly performed Solexa deep sequencing to profile miRNAs expressed in chicken skeletal muscle tissues. Sequence tags analyses not only enable us to report a group of highly abundant known miRNAs expressed in skeletal muscles but most importantly to identify novel putative chicken miRNAs from skeletal muscle tissue. Further miRNA transcriptome comparison and real-time RT-PCR validation experiments revealed seveal differentially expressed miRNAs between broilers and layers.
Project description:Contains 90 Sinperca chuatsi miRNAs identified in fast and slow muscle fibers, and 60 miRNAs showed significantly different levels of expression.