Divergent gene expression through PI3K/akt signalling pathway cause different models of hypertrophy growth in chicken

RNA-Seq technology was used to investigate differences in the gene expression of pectoralis muscle tissue between two chicken breeds [Ross as commercial (rapidly growing) and Isfahani as Iranian local breed (slow-growing)]. Total RNA was isolated from breast muscle samples at end of 4 weeks of age and sequenced by an Illumina Hiseq 2000 sequencer. Hierarchical Indexing for Spliced Alignment of Transcripts (HISAT2) was applied to align clean reads to chicken reference genome. Then, Cufflinks package was used to assemble transcripts and identify significantly differentially expressed genes (DEGs). Between two groups, the 606 significantly DEGs were identified (p-adjusted <=.05). The confirmation of RNA-seq data was performed by Quantitative real-time PCR (qRT-PCR), consistent expression results were found for 10 selected genes. This study identified DEGs that regulate peroxisome proliferator-activated receptors (PPAR) signalling and Phosphatidylinositol-3 kinase Akt (PI3K/Akt) pathways in the Commercial breed, which might contribute to its higher metabolism of energy and growth characteristics compared to the Native breed. Our results suggested that the different expression patterns of some interesting genes including the PIK3IP1, SGK1, FOXO3, FBXO32, FBXO30, CUL3 and ASB1 in Native chicken might represent a cause for the poor growth performance for this breed than the Commercial breed.