Date of Award
Doctor of Philosophy (PhD)
Extensive studies have revealed the complex mechanisms underlying the roles of the microtubule system in fundamental cellular processes, the severe consequences in development and health resulted from its anomaly, and the irreplaceable therapeutic agents that perturbs this vital yet inherently unstable cytoskeletal system. Most of the concepts derived from a handful of model organisms become dogma of the field despite contrary observations. By overcoming a major limitation of biflagellate green alga Chlamydomonas - the intense autofluorescence common to photosynthetic cells - this dissertation discovered new phenomena of the microtubule system and conceived an invention. The microtubule system of the green alga is exceedingly sensitive to H+ and Na+ , contrary to the perceived tight control of this cytoskeleton in best known for its dynamic instability, but similar to stress-induced changes in plants. This indicates that this presumptive conserved system has diverged substantially. Organisms potentially could use a sensitive microtubule system to sense mechanical force as well as osmotic pressures. On the other hand, they must adapt or perish when global environments promise to alter the concentrations of H+ and Na+ at an accelerated pace in the coming decades. H+ and Na+ -induced changes of algal microtubule system are rapid. Quantification of the rapid responses in real-time inspired the conversion of the microtubule-based biological nanomachine that drives the rhythmic beating of Chlamydomoans flagella into fluorescent intensity standards. The large-scale preparation of flagellar standards from the transgenic green algae will accelerate broad implementation of quantitative fluorescence microscopy. Collectively, its two outcomes will have broad impacts on multiple fronts. This dissertation encourages researchers to take a fresh look at the well-understood microtubule system in the green algae.
Available for download on Wednesday, June 27, 2018