Intranuclear microtubules

Effect of uncouplers of oxidative phosphorylation on microtubule location and surface structure in murine mast cells

"Uncouplers" of oxidative phosphorylation (sodium azide, DNP, and oligomycin) alter the location of microtubules within murine mast cells. Both cytoplasmic microtubules, perpendicular to the plasma membrane within cell surface folds, and intranuclear microtubules were observed. In addition, one or more dense plaque-like structures adjacent the plasma membrane in mast cells appeared following incubation in the antimetabolities. Intranuclear microtubules and cytoplasmic microtubules within the cell surface ridges disappeared in azide-treated mast cells that were reincubated or "recovered" in PBS. However, both these structures remained in oligomycin- and DNP-treated murine mast cells following reincubation.

Increase induced by colchicine in the incidence of somatic crossing over in Glycine max

The frequency of somatic crossing over in Glycine max has been significantly increased by soaking the dry seeds in aqueous solutions of 0.0025, 0.005 and 0.01% colchicine. This increase was quite consistent for several treatments involving time × concentration interaction as well as in cases where post-treatment with mitomycin C was given. Results indicate that colchicine is inefficient in disturbing the arrangements of segments of homologous chromosomes involved in the process of somatic exchanges before the onset of the process of somatic crossing over.