Deep Sequencing-Based Transcriptome Analysis of Chicken Spleen in Response to J Subgroup Avian Leukosis Virus (ALV-J) Infection.

Purpose: The goals of this study are to investigate the differentially expressed genes between ALV-J infected (WRR+) and uninfected (WRR-)chickens spleens by Illumina deep sequencing. Methods: 140-day-old female chickens of White Recessive Rock (WRR) were confirmed as J subgroup avian leukosis virus (ALV-J) infection. Total RNA from three ALV-J-infected spleens (designated: WRR1+, WRR2+, WRR3+) and three uninfected normal spleen samples (designated: WRR1-, WRR2-, WRR3-) was isolated by TRIzol following the manufacturer's instruction (Invitrogen, CA, USA). RNA samples of three individuals within each group were pooled with equal amounts, and then were subjected to Illumina deep sequencing by Illumina Genome Analyzer IIx. Results: Through raw data processed, 49,979,648 and 43,704,401 clean reads with an average length of 101 bp, which represented total residues of 4,859,084,087 and 4,238,826,168 bp, were obtained for WRR- and WRR+ libraries, respectively. Subsequently, the clean reads in the two libraries were assembled. Altogether, 121,493 contigs were assembled with an average length of 927 bp (ranged from 300 bp to 23,402 bp), leading to generation of 82,829 unigenes. The length of unigenes varied from 351 bp to 28,928 bp, with an average length of 1,155 bp. Based on the FPKM value of each gene, 252 DEGs were identified by DEGseq package using Benjamini-q-value of 0.05 as a cut-off. In ALV-J infected spleens, 90 genes showed up-regulated and 162 showed down-regulated expression when compared to uninfected samples. Conclusions: Our study represents the first time to elucidate the ALV-J infected chickens'spleens at the transcription level by RNA-seq technology. A total of 252 genes were found to be differentially expressed in ALV-J infected spleens when compared to uninfected chickens. These genes can be considered as candidates for further study ALV-J invasion. Overall design: Spleen mRNA profiles of 140-day-old ALV-J infected (WRR+) and uninfected (WRR-) female chickens of White Recessive Rock were generated by deep sequencing, using Illumina Genome Analyzer IIx.

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Li Z, Luo Q, Xu H, Zheng M, Abdalla BA, Feng M, Cai B, Zhang X, Nie Q, Zhang X