Alternative Splicing Analysis Of Small Intestine Transcriptome Before And After The First Laying Of Laying Hens

During the laying period,the physiological functions of the laying hens will change significantly to satisfy the deposition of various nutrients in the eggs.The small intestine is the main place for the digestion and absorption of nutrients in poultry.Alternative splicing is a process in which m RNA precursors generate mature m RNA through the selection and combination of different splicing sites.This process is specific to the type and developmental stage of the tissue.Therefore,this study took laying hens as the research object,obtained the transcriptome data of the duodenum,jejunum and ileum one week before and one week after the first laying.The Hisat2 software was used to align RNA-seq data to chicken genome sequence.The r MATS software was used to analyzes the different alternative splicing situation not only of the duodenum,jejunum,and ileum before and after the first laying,but also of the small intestine before and after the first laying to obtain differential alternative splicing gene.Differential alternative splice genes were enriched for GO and KEGG functions.The enriched genes will undergo gene expression analysis.The results of this study are as follows:(1)A week before the first egg laying,a total of 16,401 alternative splicing events were identified in the duodenum and jejunum,involving 7,366 genes,of which 136 differentially spliced genes were enriched in biological processes related to mitosis.There are 19,009 alternative splicing events and 7249 genes in the duodenum and ileum groups,including 412 differentially spliced genes,which are enriched by biological processes such as phosphatidylinositol metabolism.The number of alternative splicing events and genes in the jejunum and ileum groups were 18411 and 7179,respectively,of which 342 differentially spliced genes were enriched in biological processes related to lipid metabolism.After the first egg laying,a total of 15011 alternative splicing events and 6372 genes were identified in the duodenum and jejunum,of which 134 differentially spliced genes were enriched in biological processes such as protein metabolism;There are16905 alternative splicing events and 6657 genes in the duodenum and ileum groups,of which 277 differentially spliced genes are enriched in biological processes such as transportation along microtubules;The jejunum and ileum have a total of 169 differentially spliced genes in 16629 alternative splicing events and 6747 genes,which are enriched in biological processes such as monosaccharide biosynthesis.(2)In the duodenum,a total of 17,645 alternative splicing events were identified one week before and one week after the first laying,involving 6952 genes,including 296 differentially spliced genes.There were17630 alternative splicing events and 6940 genes before and after jejunum laying,including 206 differentially spliced genes.In the ileum group,there were a total of 192 differentially spliced genes among17603 alternative splicing events and 6994 genes.After GO function enrichment,the differentially variable genes before and after laying eggs in the duodenum and jejunum are enriched in the biological processes related to mitosis and transportation along the microtubules.Differential variable genes in the ileum are enriched in biological processes related to lipid metabolism and enteric nerves.After KEGG analysis,the differentially spliced genes ECHS1,HACD2 and ACSL5 of the jejunum were enriched in the fatty acid metabolism pathway,and their gene expression did not change significantly.