The spindle of the colonial diatom Fragilaria contains two distinct sets of spindle microtubules (MTs): (a) MTs comprising the central spindle, which is composed of two half-spindles interdigitated to form a region of "overlap"; (b) MTs which radiate laterally from the poles. The central spindles from 28 cells are reconstructed by tracking each MT of the central spindle through consecutive seri...

Microtubules (MTs), one of the three cytoskeletal structures in all eukaryotes, play key roles in many fundamental cellular and developmental processes such as cell growth, cell shape, cell division, cell differentiation and intracellular transport. MTs are cylindrical polar polymers made up of repeating aand b-tubulin. MTs undergo alternating phases of polymerization and depolymerization. Like...

We have investigated the sites of microtubule (MT) assembly in neurons during axon growth by taking advantage of the relationship between the proportion of tyrosinated alpha-tubulin (tyr-tubulin) in MTs and their age. Specifically, young (newly assembled) MTs contain more tyr-tubulin than older (more long-lived) MTs. To quantify the relative proportion of tyr-tubulin in MTs, cultured rat sympat...

A large body of evidence indicates that microtubules (MTs) conduct organelle transport in axons, but recent studies on extruded squid axoplasm have suggested that actin microfilaments (MFs) may also play a role in this process. To investigate the separate contributions to transport of each class of cytoskeletal element in intact vertebrate axons, we have monitored mitochondrial movements in chi...

Transl Androl Urol, Vol 3, Suppl 1 September 2014 www.amepc.org/tau © Translational Andrology and Urology. All rights reserved. Introduction: Stem cells (SCs) show significant benefits in the treatment of post-prostatectomy erectile dysfunction (ED).However, the low retention rate of the tranditional single cell strategy at the injection sites limits its therapeutic potential. Aim: To investiga...

Wnt5a guides cortical axons in vivo by repulsion and in vitro evokes cortical axon outgrowth and repulsion by calcium signaling pathways. Here we examined the role of microtubule (MT) reorganization and dynamics in mediating effects of Wnt5a. Inhibiting MT dynamics with nocodazole and taxol abolished Wnt5a evoked axon outgrowth and repulsion of cultured hamster cortical neurons. EGFP-EB3 labele...

Fourteen breast cancer lines (8 human, 5 rat, and 1 mouse) have been studied in terms of their ability to form multicellular tumor spheroids (MTS) with the agar-base method. Only 8 of the lines formed MTS in contrast to a 100% efficiency in a series of 11 varied tumors reported in the initial studies with this method. We have compared the lines that do and do not form MTS in terms of a variety ...

An understanding of the mechanism and structure of microtubule (MT)-nucleating sites within the pericentriolar material (PCM) of the centrosome has been elusive. This is partly due to the difficulty in obtaining large quantities of centrosomes for analysis, as well as to the problem of attaining interpretable structural data with conventional EM techniques. We describe a protocol for isolating ...

Manski (1997) and Manski and Pepper (2000) gave sharp bounds on causal effects under the assumptions of monotone treatment response (MTR) and monotone treatment selection (MTS). VanderWeele (2008) provided bounds for binary treatment under an assumption of monotone confounding (MC). We discuss the relation between MC and MTS and provide bounds under various combinations of these assumptions. We...

Microtubules (MTs) are long non-covalent polymers of heterodimeric tubulin that exchange with the soluble pool exclusively from their ends. The two opposite ends of MT are different: one end of the MT (plus end) is more dynamic than the opposite (minus) end. At steady state, plus ends of individual MTs undergo long excursions of growth and shortening. In many animal cells, MTs run from the cell...