Transcriptomic Analysis Of Spleen And Screening Of Immune Related Genes In Lueyang Black-bone Chicken At Different Growth Stages

Based on the determination of growth traits such as body weight,spleen weight and spleen development status of Lueyang black-bone chicken,the differentially expressed genes(DEGs)and key genes affecting spleen development were identified by transcriptome sequencing and bioinformatics analysis.The purpose of this study was to further explore the growth and development of spleen in Lueyang black-bone chicken and the related genes invovled in pathways of immunity,which could contribute to unveil its intrinsic molecular mechanism.Three Lueyang black-bone chickens of 7 days,30 days and 120 days with the same feeding conditions were selected.Body weight and spleen weight were measured.Subsequently,histological analysis of chicken spleen was carried out by tissue section,and transcriptome sequencing of spleen tissues of Lueyang black-bone chicken was performed via RNA-seq technique.The main results are as follows:Histological observation of spleen: T,B lymphocytes and lymphatic sheath began to appear in the spleen of 7days old Lueyang black-bone chicken,and the number of T,B lymphocytes and lymphatic sheaths were increasing in the spleen of Lueyang black-bone chickens at the age of 30 days,and the morphology of lymphatic sheath was almost stable.There were no significant differences between the spleens at the age of 120 days and that of 30 days.Screening differentially expressed genes by transcriptome sequencing data: 340 DEGs were found between 7 days and 30 days chicken,174 DEGs expressed genes between 30 days and 120 days smaples,and 1100 DEGs expressed genes between 7 days and 120 days chcikens.There were 17 co-differentially expressed genes in the three groups.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis of DEGs: DEGs between 7 days and 30 days samples were mainly enriched in immune-related items such as external stimulus response,leukocyte migration,cell chemotaxis,granulocyte migration and defense response.The DEGs at 30 and 120 days samples were mainly enriched in immuno-related items such as cell chemotaxis,regulation of interleukin-1,external stimulus response,bacterial defense response and chemokine receptor binding.The DEGs at 7 days and 120 days samples were mainly concentrated in cell cycle,mitotic mitosis,chromosome concentration,centromere and spindle microtubules and other items related to cell division.The other three groups were enriched in hematopoietic cell lineage signaling pathway,neuroactive ligand-receptor interaction signaling pathway and cytokine-cytokine receptor interaction signaling pathway,which were enriched in all samples.Weight gene co-expression network analysis(WGCNA): Weighting gene co-expression network associated with traits was constructed,and hub genes related to chicken growth and development were EVL,FGD3,TNIK,QRICH1,ZYX,TBL1 X,IFT80,SF3B1,CEPT1,MYH9,POLH and MICAL1;hub genes affecting immune function of Lueyang black-bone chicken were EVL,VAV3,TNIK,NLRC3,IL2 RB,RPS25,WBP1 L,DX17,ABHD10,PON2,FANCD2 and CD3E.