Identification of key genes and molecular mechanisms associated with low egg production of broiler breeder hens in ad libitum

Overfeeding reduces laying performance in broiler breeder hens (Gallus gallus domesticus). To unravel the effect of feeding regimes on energy metabolism and egg production, high-throughput RNA sequencing was utilized to identify differentially expressed genes (DEGs) in ovary, liver and adipose tissues of broiler chickens under ad libitum and restricted feeding. The transcriptome analysis showed that 289, 388 and 204 DEGs were identified in the adipose tissue, liver and ovary, respectively, between ad libitum and restricted feeding groups. Bioinformatics analysis by STRING further revealed DEGs were significantly enriched in phagosome pathway, lipid transport and location biological process, and the molecular function of lipid transporter activity and nutrient reservoir activity in ovary; the pathways of “steroid hormone biosynthesis” and “metabolism of xenobiotics by cytochrome P450”, and the molecular function of nutrient reservoir activity in adipose tissue; the metabolic pathways, Jak-STAT signaling pathway and PPAR signaling pathway in liver. Overall design: Gene expression from 3 tissues including adipose, liver and ovary of hens under ad libitum(3 hens) and restricted feeding(3 hens) was measured by Illumina HiSeqTM PE125.