Regional variation of microtubule flux reveals microtubule organization in the metaphase meiotic spindle.

ABSTRACT: Continuous poleward movement of tubulin is a hallmark of metaphase spindle dynamics in higher eukaryotic cells and is essential for stable spindle architecture and reliable chromosome segregation. We use quantitative fluorescent speckle microscopy to map with high resolution the spatial organization of microtubule flux in Xenopus laevis egg extract meiotic spindles. We find that the flux velocity decreases near spindle poles by approximately 20%. The regional variation is independent of functional kinetochores and centrosomes and is suppressed by inhibition of dynein/dynactin, kinesin-5, or both. Statistical analysis reveals that tubulin flows in two distinct velocity modes. We propose an association of these modes with two architecturally distinct yet spatially overlapping and dynamically

SUBMITTER: Yang G 

PROVIDER: S-EPMC2518697 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature