Pharmacological identification of signaling mechanisms regulating flagellar length in Chlamydomonas

Prachee Avasthi and Wallace Marshall

Biochemistry & Biophysics, UCSF, San Francisco CA, USA

Abnormal cilia length has a variety of pathologic consequences. The flagella of the unicellular green alga Chlamydomonas reinhardtii are an excellent model in which to study length control of cilia. A variety of mutations have been found that result in abnormal elongation or shortening of flagella in this system. However, signaling pathways affected in these mutant lines remain largely a mystery. Previously, chemical modification of flagellar length has been observed. In order to directly probe pathways that regulate flagellar length, we utilized a large number of small molecules with known molecular targets to screen for changes in flagellar length. We identified a variety of compounds targeting several distinct pathways that result in flagellar shortening without complete deflagellation. In addition to identifying mechanisms that are required for normal flagellar maintenance, these compounds are excellent tools that can be used to identify gene function in existing and newly discovered flagellar length mutants.

e-mail address of presenting author: pacrofts@gmail.com