Transcriptome profiling of H. polymorpha in response to Cd exposure.

To gain insight into the basic mechanism of Cd detoxification in the methylotrophic yeast, H. polymorpha, we analyzed temporal changes in transcriptional profiles in response to Cd exposure. We used H. polymorpha whole-genome cDNA microarrays, which contain 98% of all H. polymorpha ORFs in duplicate or triplicate. Keywords: time course, cadmium Total RNA samples were collected from H. polymorpha cells after 15, 30, 60, and 120 min incubation with 300μM Cd. Using the RNA sample obtained prior to Cd addition as a reference, the differential fluorescence intensities of each RNA sample prepared at the indicated times were measured after labeling with Cy3 or Cy5 fluorochromes. For all analyses, we performed dye swapping experiments to avoid dye bias, thus four or six intensity values were generated for each ORF and averaged for analysis.