Quantitative analysis of cell-type specific gene expression in the green alga Volvox carteri.
BACKGROUND
The multicellular alga Volvox carteri possesses only two cell types: mortal, motile somatic cells and potentially immortal, immotile reproductive cells. It is therefore an attractive model system for studying how cell-autonomous cytodifferentiation is programmed within a genome. Moreover, there are ongoing genome projects both in Volvox carteri and in the closely related unicellular alga Chlamydomonas reinhardtii. However, gene sequencing is only the beginning. To identify cell-type specific expression and to determine relative expression rates, we evaluate the potential of real-time RT-PCR for quantifying gene transcript levels.


RESULTS
Here we analyze a diversified pool of 39 target genes by real-time RT-PCR for each cell type. This gene pool contains previously known genes with unknown localization of cellular expression, 28 novel genes which are described in this study for the first time, and a few known, cell-type specific genes as a control. The respective gene products are, for instance, part of photosynthesis, cellular regulation, stress response, or transport processes. We provide expression data for all these genes.


CONCLUSIONS
The results show that quantitative real-time RT-PCR is a favorable approach to analyze cell-type specific gene expression in Volvox, which can be extended to a much larger number of genes or to developmental or metabolic mutants. Our expression data also provide a basis for a detailed analysis of individual, previously unknown, cell-type specifically expressed genes.
Nematollahi
Ghazaleh
G
Department of Cellular and Developmental Biology of Plants, University of Bielefeld, Universitätsstr, 25, D-33615 Bielefeld, Germany. ghazaleh.nematollahi@uni-bielefeld.de <ghazaleh.nematollahi@uni-bielefeld.de>
Kianianmomeni
Arash
A
Hallmann
Armin
A
D020418:Algal Proteins / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D020869:Gene Expression Profiling / Q000379:methods*; D008969:Molecular Sequence Data; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D016415:Sequence Alignment; D044446:Volvox / Q000166:cytology / Q000235:genetics*
D020418:Algal Proteins