Spindle composition changes during development and between cell type to regulate spindle length (Loughlin et al., 2011; Wilbur and Heald, 2013).
We demonstrated that spindle composition also affects spindle shape in a length-dependent manner.
In total, these changes in spindle composition give rise to anisotropic scaling of the spindle and reveal a mechanism that generates spindle shape diversity.
Considering the above, we would say that the cell size-driven mitotic scaling during cleavage divisions of Xenopus [ 58] would fall into the class of direct scaling, while the extract composition-driven meiotic spindle length variation between different Xenopus species [ 63] would fall into the class of programmed scaling.
The majority of these species were never examined cytologically, so characteristics of spindle orientation, composition, and pronucleus location are unknown and cannot be compared with D. mangabeirai or D. mercatorum, where they have been well-described.
We secondly analysed the constitutive microtubular network composition and the aberrant spindle multipolarisation process after paclitaxel exposure in these sublines as potential causes for differential effect of paclitaxel on chromosomal stability.
One hypothesis to explain these differences is the separate development of specialized mechanisms to orchestrate open mitosis in metazoan and plant lineages, leading to the evolution of different nuclear envelope compositions, targeting mechanisms, and mitotic spindle nucleation in the plant and animal kingdoms.
Abnormalities in mitotic spindle formation, centrosomal division or PCM composition appeared not to be increased by the knockdown (data not shown).
Thus, fixed-cell studies of outer-kinetochore composition and kinetochore-microtubule configuration show that monopolar spindles of both monastrol-treated and untreated cells display lateral kinetochores that are similar in their astrin and Mad2 recruitment status.
For this purpose, we analysed basal and paclitaxel-induced chromosome missegregation, apoptosis and aberrant spindle multipolarisation as well as microtubular network composition for each subline.
