We have investigated the intracellular roles of an Xklp2-related kinesin motor, KRP(180), in positioning spindle poles during early sea urchin embryonic cell division using quantitative, real-time analysis. Immunolocalization reveals that KRP(180) concentrates on microtubules in the central spindle, but is absent from centrosomes. Microinjection of inhibitory antibodies and dominant negative co...

In this paper we provide an extension of the Chebyshev orthogonal rational functions with arbitrary real poles outside [−1, 1] to arbitrary complex poles outside [−1, 1]. The zeros of these orthogonal rational functions are not necessarily real anymore. By using the related para-orthogonal functions, however, we obtain an expression for the nodes and weights for rational Gauss-Chebyshev quadrat...

Chromosome biorientation, where sister kinetochores attach to microtubules (MTs) from opposing spindle poles, is the configuration that best ensures equal partitioning of the genome during cell division. Erroneous kinetochore-MT attachments are commonplace but are often corrected prior to anaphase. Error correction, thought to be mediated primarily by the centromere-enriched Aurora B kinase (AB...

Glycogen synthase kinase-3 (GSK-3 ) is known to play a role in the regulation of the dynamics of microtubule networks in cells. Here we show the role of GSK-3 in the proper formation of themitotic spindles through an interaction with GCP5, a component of the -tubulin ring complex ( TuRC). GCP5 bounddirectly toGSK-3 in vitro, and their interactionwas also observed in intact cells at endogenous l...

BACKGROUND Fluorescence membrane markers are efficient tools for visualizing the dynamics of membrane recycling processes in living cells. The outer hair cell (OHC) - a bipolar epithelial cell in the cochlea - possesses endocytic activity at both its apical and basal poles. The best visual overview of transcytosis in the OHC is achieved when the cell is isolated, so that both the apical and the...

Preoperative 3D CT imaging techniques provide displacement analysis of the distal scaphoid fragment in 3D space, using the matched opposite scaphoid as reference. Its accuracy depends on the presence of anatomical bilateral symmetry, which has not been investigated yet using similar techniques. Our purpose was to investigate symmetry by comparing the relative positions of distal and proximal po...

Accurate chromosome segregation requires that the two sister kinetochores attach to microtubules from opposite spindle poles. New work reveals how a kinetochore can segregate properly while remaining improperly attached to two spindle poles.

This paper studies the structural properties of both 3nite poles and the in3nite pole of linear time-invariant singular systems under output feedback. Three main problems are studied, namely, (1) the algebraic structures of both 3nite poles and the in3nite pole; (2) the assignability of 3nite poles and the elimination of the in3nite pole by output feedback; and (3) the controllability and obser...

Using live imaging and computer simulation, Kozlowski et al. (2007) show that an interplay between spindle pole movements, microtubule dynamics, and microtubule bending contribute to asymmetric spindle placement in the C. elegans embryo.