Transcriptome Analysis Reveals the Dynamic of Alternative Splicing Landscape in Chicken Pituitary during Different Reproductive Period

Background:Chicken broodiness is strictly controlled by a series of genes in hypothalamic–pituitary–gonadal axis. The transcriptome diversity and expression of those genes could be regulated by alternative splicing during chicken reproductive period. Transcritpome sequencing is an efficient and reliable technology for revealing diversity of alternative splicing in pituitary tissues during the chicken reproductive cycles.

Results: The RNAseq data in 4 samples show that 4,010 genes are subject to alternative splicing in XH chicken pituitary, accounted for 24% proportion of total expression gene in pituitary. The total number of 15,501 novel junctions are detected.  Exon Skipping is the most frequent AS event in chicken pituitary. Out of 1,055 novel junctions that are specific-expressed in egg-laying state, 306 novel junctions are observed in broodiness state. The most enriched GO functions of the genes are organismal development, nervous system development and function, tissue morphology, connective tissue development and function, and organ development. Comparison between AS data in egg-laying state and that in broody state indicates that 290 genes have different expression isoforms and are involving in some crucial pathway such as MAPK Signaling pathway (MAP2K1IP1, DUSP1, FLNB, SOS2, MEF2C, RPS6KA3, and MAPK14 ), phosphatidylinositol signaling pathway (PI4KA, PIK3CG,and PIB5PA ), biosynthesis of steroids (MVD, DHCR7). Some genes (e.g. NPY and GRP) related to chicken reproductive traits are undergoing alternative splicing. Their isoforms are differentially expressed between egg-laying state and broody state.

Conclusion: We provide the alternative splicing landscape in chicken pituitary and reveal the dynamic of alternative splicing in chicken transcriptome during reproductive period.