抄録
We have developed a large-scale oligo DNA microarray of the ascidian, Ciona intestinalis to investigate global gene expressions of the ascidians. Using this oligo DNA microarray, we obtained the expression profiles of 10, 415 genes of C. intestinalis and categorized them into 5 large clusters; embryonic gene cluster A, embryonic and adult gene cluster B, adult gene cluster C, stably-expressed gene cluster D and maternal gene cluster E, and 49 sub-clusters based on expression patterns during the life cycle. Each subcluster contained functionally related genes. We also used DNA microarrays to detect up- or down-regulated genes in ascidians after exposure to organotin compounds, a serious marine pollutant. We found that organotin compounds up- or down-regulated more than 300 genes. We also found that many of the down-regulated genes belonged to Clusters B and C, especially the c1 (immune-related genes) and c4 (juvenile-specific genes) sub-clusters. As well, most of the up-regulated genes also belonged to Clusters B and C. From the array results, we estimated that organotin compounds have effects on ascidian embryogenesis, metamorphosis and immunity. Our experimental results confirmed that organotin compounds inhibited embryogenesis and morphogenesis of ascidians. These findings demonstrated that the combination of our analyses of genes up- or down-regulated by chemicals and the categorization of those genes by our classification method is a valuable method for estimating the effects of chemical pollutants on ascidians. Such applications provide a unique method for monitoring and for making risk assessments of marine chemical pollutants.
