Abstract
Cortical microtubules are responsible for the determination of cell elongation polarity. Previously, we reported that each of the 42 mutants with helical growth phenotypes has a dominant-negative mutation in a tubulin gene. Quantitative analysis of cortical microtubule arrangement and slanting growth angle indicated a tight correlation between elongating direction and cortical microtubule array orientation.
Microtubule structure is highly conserved in eukaryotes. Stable heterodimers of α-tubulin and β-tubulin are stacked longitudinally to form a tubulin protofilament and 13 protofilaments normally are associated laterally to form a hollow microtubule. in vitro microtubules other than 13 protofilament numbers can be formed and are shown to be slightly twisted. To examine whether altered protofilament number may underlie the skewed array organization, we established TEM technique to observe the number of protofilaments in wild type and the mutants.
In addition, we will report highly altered dynamics of cortical microtubules in several twisting mutants.
