Mapping the deflagellation-defective ADF1 gene in Chlamydomonas reinhardtii.

Cilia function in motility, chemo- and mechanosensation and have been linked to the cell cycle and human disease. Stress triggers the calcium-dependent severing of axonemal microtubules at a site near the base of the cilium, resulting in deciliation (also known as deflagellation). Originally isolated as a spontaneous mutation in Chlamydomonas reinhardtii, the adf1-1 mutant is defective in Ca2+ influx that triggers deflagellation. Five new alleles of adf1 were recovered from UV and insertional mutagenesis screens, but none of the alleles were tagged with insertional DNA. I have used PCR based recombination mapping to place ADF1 in a 394 kb region of linkage group IX. Six BACs spanning the region have been used to transform mutant adf1 strains, with the goal of rescuing the phenotype. BAC transformations have not yielded a rescue; therefore, several candidate genes have been subcloned and are being used in attempts to identify the elusive gene.