BioProject

A deletion mutation in the growth hormone receptor (GHR) gene results in the inhibition of skeletal muscle growth and fat deposition in dwarf chickens. More...

A deletion mutation in the growth hormone receptor (GHR) gene results in the inhibition of skeletal muscle growth and fat deposition in dwarf chickens. In this study, microarray techniques were used to detect the miRNA and mRNA expression profiles of 14-day-old embryo and 7-week-old chicken skeletal muscle of deletion-type dwarf chickens and normal-type chickens. Skeletal muscle tissues of Dwarf recessive White Rock chickens and normal recessive White Rock chickens were used to make the microarray assay. Results show the expression of miR-1623 and miR-181b in 14-day-old embryos and of let-7b and miR-128 in 7-week-old chickens. let-7b was the only miRNA found to be completely complementary to its target in the 3'UTR of GHR and inhibited GHR gene expression. KEGG (Kyoto Encyclopaedia of Genes and Genomes) pathway analysis and RT-PCR verified that there were three main signalling pathways regulating the skeletal muscle growth and fat deposition of chickens influenced by the let-7b-regulated GHR gene. The suppression of the cytokine signalling 3 (SOCS3) gene was found to be involved in the signalling pathway of adipocytokines. We found that let-7b is the critical miRNA involved in the regulation of the GHR gene. SOCS3 plays a critical role in the network regulating skeletal muscle growth and fat deposition via let-7b-mediated GHR gene expression. Overall design: Two groups were analyzed in the array assay: one group consisted of normal recessive White Rock 14-day-old embryo leg muscle tissues, and the other group consisted of dwarf recessive White Rock 14-day-old embryo leg muscle tissues. The control samples were labeled as A1, A2, A3, and the dwarf chicken samples were labeled as B1, B2, and B3. 9 total embryos per breed, 3 embryos used per breed for each sample. 523 mature miRNA sequences were assembled and integrated into the LC miRNA microarray design, and different expression miRNAs were measured on the 7000HT Fast Real-Time PCR system. This submission represents the miRNA profiling component of the study. Less...