Abstract
Background: Changshun green-shell laying hen with strong broodiness is a Chinese indigenous chicken breed. Little is known about the mechanisms responsible for ovary development of Changshun green-shell laying hens from egg-laying period (LP) to incubation period (BP). Here, RNA sequencing (RNA-seq) of ovaries from Changshun hens in LP and BP was performed to identify candidate genes and pathways associated with broodiness.
Results: We identified 1650 differently expressed genes (DEGs), including 429 up-regulated and 1221 down-regulated DEGs, in chicken ovaries between LP and BP groups. GO and KEGG analysis further revealed that these DEGs were mainly involved in the pathways related to follicle development in chicken ovaries, including focal adhesion, MAPK signaling pathway, and FoxO signaling pathway, and vascular smooth muscle contraction, ECM-receptor interaction, and GnRH signaling pathway were down-regulated in incubating ovaries. Eight candidate genes (EGFR, VEGFRKDRL, FLT1, KDR, PDGFRA, TEK, KIT and FGFR3) related to angiogenesis, folliculogenesis, steroidogenesis and oogenesis in ovaries were suggested to play important roles in the ovarian development of Changshun hens during the transition from LP to BP.
Conclusions: We discovered critical genes and pathways which is closely associated with ovary development in incubating chickens, indicating the complexity of reproductive behaviour of different chicken breeds.