Search

MicroRNAs (miRNAs) and mRNAs establish a complex regulatory network influencing diverse biological pathways including muscle development and growth. Elucidating miRNA-dependent regulatory networks involved in muscle development could provide additional insights into muscle traits largely predefined during prenatal development. The present study aimed to determine differentially expressed transcripts and functional miRNA- mRNA relationships associated with different stages of skeletal muscle development in two pig breeds, German Landrace and Pietrain, distinct in muscle characteristics. A comparative transcriptional profiling of longissimus dorsi muscle tissues from fetuses at 35, 63 and 91 days post-conception as well as adult pigs (180 days postnatum) was performed using the Affymetrix GeneChip porcine genome microarray. Differential expression patterns were identified to be associated with muscularly developmental stages and breed types. The integration of miRNA expression data and ingenuity pathways analysis (ipa) pathway analysis revealed several miRNA-dependent regulatory networks related to muscle growth and development. The present results provide insights into muscle biology for further improvement of porcine meat quality. [ABSTRACT FROM AUTHOR]

Examines the sequencing, single nucleotide polymorphism identification and mapping of the porcine parathyroid hormone-like hormone (PTHLH) gene to chromosome 5. Role of PTHLH in calcium metabolism; Regulation of endochondrial bone development and epithelial mesenchymal interactions during the formation of mammary glands, skin and teeth; Identification of a single nucleotide polymorphism within the coding region.

The glucocorticoid receptor (GR) is a ubiquitously acting transcription factor that is responsible for mediating the physiological response to stress and adaptation to environmental conditions. Genetic variation of a GR gene (NR3C1) may therefore contribute to multiple phenotypic alterations and influence relevant traits of animal production. Here, we examined effects of two non-synonymous mutations of the porcine NR3C1, leading to amino acid exchanges p.Glu13Asp (c.39A>C) and p.Val19Leu (c.55G>C) in the N-terminal domain of the GR, on meat quality and carcass composition. In addition, we explored their influence on transcriptional activity of GR in vitro. A commercial crossbreed Pietrain × (German Large White × German Landrace) herd (n = 545) in which genotypes and relevant traits had been collected was used to perform the association analysis. The single nucleotide polymorphism (SNP) c.55G>C was significantly associated with conductivity and meat color scores. These effects were highly consistent considering the physiological relationship between these traits. Association analysis of SNP c.39A>C also revealed significant effects on closely connected meat quality traits. In addition, SNP c.55G>C showed association with carcass traits, mainly those related to muscle deposition. The molecular mechanism of action of both amino acid substitutions remains obscure because neither showed significant influence on transcriptional activity of GR. Our study emphasizes NR3C1 as an important candidate gene for muscle-related traits in pigs, but further work is necessary to clarify the molecular background of the identified associations., (© 2013 Stichting International Foundation for Animal Genetics.)