Transcriptome Analysis Of SP600125-induced Tetraploid Cells

SP600125 induced homologous tetraploid carp cell line(SP4n)is a stable tetraploid cell line from diploid crucian carp fin cells(2n).In order to further understanding of SP4 n cells biological characteristics,in this study,we used mRNA sequencing to investigate global expression in SP4 n cells through comparison with the 2n cells and tetraploid carp cells(JL4n).Main findings in this paper are as follows:1.Expression profile analysis of the SP4 n cells and 2n cellsThe total of 663 differentially expressed genes in the SP4 n cells and 2n cells,of which 255 were significantly up-regulated(38.46%)and 408 were significantly down-regulated(61.54%).The enrichment analysis of GO and KEGG databases showed that the differentially expressed genes were closely related to cell adhesion migration,calcium ion regulation,and energy metabolism.Transcriptome data and qRT-PCR results showed that the same expression trends in genes associated with regulation of cell cycle in both the SP4 n cells and 2n cells.2.Expression profile analysis of the SP4 n cells and JL4 n cellsThe total of 35,599 differentially expressed genes in the SP4 n cells and JL4 n cells,of which 30,449(85.53%)were significantly up-regulated and 5150(14.47%)were significantly down-regulated.KEGG difference enrichment analysis and qRT-PCR results showed that there were significant differences in genes associated with regulation of cell cycle between the SP4 n cells and JL4 n cells.3.Expression analysis of genes related to energy metabolism in SP4 n,2n and JL4 n cellsThe transcriptional levels of genes related to mitochondrial function were further analyzed and the cellular ATP content was determined.The results showed that the mRNA expression levels of the 13 genes related to glycolysis and oxidative phosphorylation were generally JL4 n > 2n > SP4 n,especially the transcription levels of the genes related to oxidative phosphorylation were significantly different.The morphological structure of mitochondria in SP4 n cells was different from that of 2n and JL4 n,but the level of ATP per unit protein was basically stable.Transcription levels of sirt3,sirt4 and sirt5 genes,which were related to mitochondrial function,were expressed as SP4 n < 2n < JL4 n.Conclusion: Here,we present an analysis of mRNA expression to investigate the SP600125 induced homologous tetraploid carp cells.We performed differential expression analysis of the SP4 n cells through comparison with the 2n cells and tetraploid carp cells(JL4n).We also identified a number of mRNAs of differentially expressed genes,and founded that the difference between SP4 n cells and 2n cells is less than that between SP4 n cells and JL4 n cells.Furthermore,the SP4 n cells were significantly different from 2n and JL4 n cells in the expression profile of mitochondrial function related genes,especially the oxidative phosphorylation related genes.This research on the characteristics of the SP600125 induced tetraploid cells provides insights into the underlying molecular regulatory mechanisms of polyploidy,and lays a foundation for fish polyploid breeding induced by SP600125.