Rudy Park

Poster Presentation

Can phosphate accumulation in the cell wall of transgenic Chlamydomonas reinhardtii explain a clumping phenotype?

A transgenic strain of Chlamydomonas reinhardtii intermittently clumps at a far lower cell density than the wild type strain. The transgenic strain has a phosphatase gene involved in the Calvin cycle inserted into the chloroplast genome, which has no obvious relationship to the clumping phenotype. In order to determine whether the clumping is due to incomplete cell division / daughter cell release, we stained the cell wall for polyphosphate using DAPI (normally used to stain DNA). The mother cell will accumulate polyphosphate in its cell wall during division. Unfortunately, the staining was inconclusive due to DAPI’s ability to penetrate the cell wall and cell membrane of C. reinhardtii. Therefore, we are now planning to use a higher molecular weight polyphosphate marker that cannot penetrate the cell wall. The higher weight marker is actually a catalytically inactive phosphatase that will bind polyphosphate but will not cleave off a phosphate group.