ibclogo XVI International Botanical Congess


Abstract Number: 5617
Session = 4.15.7


MOLECULAR GENETIC ANALYSIS OF MICROTUBULE MOTORS IN CHLAMYDOMONAS


G. B. Witman, A. Koutoulis & G. J. Pazour. Dept. of Cell Biology, Univ. of Massachusetts Medical School, Worcester, MA


The ability to transform the nuclear genome of Chlamydomonas has opened the door to powerful methodologies such as gene tagging and reverse genetics. When Chlamydomonas is transformed, the transforming DNA inserts at random into the genome, disrupting or deleting genes at the site of insertion. The result is a mutation that is tagged by the exogenous DNA. The tag can be used to isolate DNA flanking the site of insertion, which in turn can be used to isolate and clone the wild-type gene. Conversely, if a gene or cDNA has been cloned but no mutations of that gene are known, insertional mutants may be screened by Southern blotting to identify those in which the gene of interest has been deleted. Using these approaches, we have characterized components of an outer dynein arm docking complex that targets the outer dynein arm to the doublet microtubules of the flagellar axoneme. In another study, we determined that an unusual isoform of cytoplasmic dynein, termed DHC1b, is the retrograde motor for intraflagellar transport (IFT), in which particles are moved from the base to the tip of the flagellum, and then back to the base. IFT is likely to be essential for the growth and maintenance of all cilia and flagella.


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