Microtubules formed arrays in the mitotic phase, including a preprophase band (PPB), the spindle apparatus at metaphase and anaphase, and the phragmoplast at telophase, in the CK treatment (Fig.
UV-B radiation caused chromosomal aberrations and induced abnormal microtubule arrays, including an asymmetric PPB, asymmetric spindle, and defective phragmoplast. The spindle was not visible in the O and OB treatments, owing to the effect of oryzalin treatment, but polykaryocytes and ring chromosomes were observed.
After chromosomes move to poles in anaphase, the phragmoplast mediates cell plate formation that completes cytokinesis.
After chromosomes move to opposite poles, [gamma]-Tubulin migrates from polar/distal surfaces of reforming nuclei to the proximal surfaces where it generates the opposing arrays of phragmoplast microtubules (Fig.
As in other marchantioids, microtubules radiate from the telophase nuclei and an interzonal
phragmoplast develops (not shown) but no wall is deposited.
Interzonal micrombules, which proliferate from proximal surfaces of reforming nuclei and plastids, forma conspicuous
phragmoplast (Fig.
Besides, all of the microtubular structures involved in cell division (spindle,
phragmoplast) have an altered position, orientation and behaviour in both cases.
Similarly, these advanced charophytes exhibit a distinctly land-plant ("embryophytic") pattern of mitotic and cytokinetic events, including, an open mitosis with a persistent, interzonal spindle (the daughter mitotic nuclei remaining separated at a distance) and a
phragmoplast (spindle fiber remnants perpendicular to the cytokinetic plane and associated golgi-derived vesicles; el.
microtubules: nonmembranous tubules about 25 nanometers in diameter and of indefinite length; located in the cytoplasm in a nondividing eukaryotic cell; form the meiotic and mitotic spindles and the
phragmoplast in a dividing cell.
hours, large, faint
phragmoplasts and unusually large daughter nuclei