Functions of Microtubules and Centrosomes In our laboratory we use the unicellular green alga, Chlamydomonas, to study the function of the centrosome and microtubules in cell organization and cell division.

In our study of centrosomes, we are interested in three questions.
1. What is the role of the basal body or centriole in the centrosome? We are addressing this question using a mutant allele at the BALD2 locus. This strain fails to assemble basal bodies and it fails to position the cleavage furrow between the two poles of the mitotic spindle. The cleavage furrow and the mitotic spindle become random with respect to one another. This allele has a recessive meiotic phenotype. We are attempting to clone the gene to determine its role in mitosis and meiosis.

2. What is the role of the centrosome in establishing cellular and flagellar asymmetry? We are addressing this question using mutant strains that have lost the normal handedness or asymmetry of the flagella. These strains were isolated because they are not able to swim toward a light source; they are phototactic defective because they have lost the inherent asymmetry of the flagella. In addition, we are examining mutant strains that assembly only one flagellum rather than two.

3. What is the role of the centrosome in progression through the cell cycle? We are isolating genes for proteins that are found in the centrosome of other organisms with the goal of using reverse genetics to look at the function of these genes. These include g-tubulin and centrin.