Transcriptional Analysis of High light Stress in Chaetoceros neogracile

Abstract

Antarctic microalga, Chaetoceros neogracile was investigated to dissect the mechanism of survival in the low temperature condition. C. neogracile was actively growing in 4℃ culture condition and the growth rate of C. neogracile under continuous light was significantly higher than the growth rate under light-dark culture condition. From the cDNA library, 2,500 randomly selected expressed sequence tags(ESTs) were prepared and generated cDNA microarray to screen differentially expressed genes in C. neogracile under high light (HL) stress condition and recovery after HL stress. Among the 1,880 genes in the cDNA microarray, there are 816 genes exhibiting differential expression (two-fold changes) under high light (HL) stress condition and recovery after HL stress. The microarray expression profiles were classified into seven cluster and then classified eleven clusters with gene expression changed time. The differential expression several selected genes was confirmed by real-time PCR. Our results indicate that the cDNA microarray approach, as employed in this work can be rlied upon and used to monitor gene expression profiles in C. neogracile.