Characterization of genes that are specific to Astaxanthin-induction in Haematococcus pluvialis

Abstract

The unicellular green alga Haematococcus pluvialis (Volvocales) is known for its massive accumulation of the ketocarotenoid astaxanthin (3,3’-dihydroxy--?,?-carotene-4,4’-dione) under unfavorable culture conditions. We used cDNA microarray (powerful tool that allows simultaneous monitoring the expression levels of numerous genes) analysis to screen differentially expressed genes in H. pluvialis under astaxanthin induction condition. Here we report the fabrication of cDNA microarray using Haematococcus cDNA libraries. And fabricated cDNA microarray was used to compare Profiling between immature and mature cells of H. pluvialis. Among 965 cDNA microarray, 65 genes are up-regulated in the gene expression profiles of Haematococcus pluvialis. To determine the expression profiles, real-time PCR were performed subsequently to evaluate the validity of meaningful molecules identified by 0.9K cDNA microarray experiment survey. Significant decrease of the expression of photosynthesis related genes was shown in mature cells. In addition, defense or stress related genes and signal transduction genes were induced in mature cells. From the results of this study, we cloned 5 different peroxiredoxin genes of H. pluvialis, and several biosynthesis of astaxanthin related genes, which will be discussed in detail.