Transcriptome analysis of BmN cells following over-expression of BmSTAT.

The Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway are involved in immune response, cell proliferation, differentiation, cell migration and apoptosis. In order to better understand the role of the JAK/STAT pathway in insects we chose Bombyx mori as an experimental model system. Over-expression of BmSTAT in a BmN cell line increased the number of cells in the G2 phase of the cell cycle. Genome-wide transcriptome analysis was performed to identify genes that were differentially expressed following BmSTAT overexpression. Transcriptome data showed that 10,853 and 10,129 expressed genes were obtained from the normal BmN cells and transformed cells, respectively. A total of 800 differentially expressed genes (DEGs) were detected, of which 787 were up-regulated and 13 were down-regulated with T test. In case of FC-test, 252 DEGs were detected, and 123 were expressed in the transformed cells and remaining were in the normal cells. Gene ontology (GO) annotation predicted a functional role for DEGs in catalytic activity, binding, transport, biological regulation, cellular and metabolic processes and pigmentation, while Kyoto encyclopedia of genes and genomes (KEGG) analysis revealed the affected genes to be involved in a multitude of cell signaling pathways. Our findings implicate JAK/STAT signaling in regulating the cell cycle in Bombyx mori, probably in combination with other pathways. These findings justify further investigation into the functional role of the BmSTAT gene.