Transcriptome Analysis of Chlamydomonas Reinhardtii During Nitrogen Starvation Using RNAseq

Despite widespread interest in algae derived biofuels, little is known about the regulatory mechanisms that induce triacylglycerol (TAG) accumulation. It has been reported in a variety of algae that during certain nutrient deplete conditions, such as nitrogen and phosphorous, TAGs accumulate. C. reinhardtii, a reference green alga, was used to investigate gene expression during nitrogen starvation. We hypothesize that in response to such conditions the cells have a time-dependent response on the transcript level. Therefore, we performed time-course experiments to analyze mRNA abundance over 48 hours of nitrogen starvation using RNAseq. In our initial qPCR experiments, we have found that the three marker genes chosen (AMT1, CHL and MLDP) show three different patterns of expression. AMT1, encoding an ammonium transporter is highly expressed within 0.5 hours of N-starvation; CHL shows a peak of expression at 4 hours and MLDP peaks at 12 hours. Results of cluster analysis on the data set will be presented to illustrate general trends of gene expression and other genes identified by RNAseq to be significantly up/down regulated will also be discussed.