Mitosis without wind

Mitosis without wind

From nuclear pore to kinetochore uclear proteins are turning up in some odd places lately. First, the nuclear-transport factor Ran was implicated in spindle formation. Then, the mitotic checkpoint proteins Mad1 and Mad2 turned up at the nuclear pore, in a switch with the mRNA export factor hRae1, which appeared with the mitotic checkpoint protein mBUB1 at the kinetochore. Now, Belgareh et al. r...

Entry into mitosis without Cdc2 kinase activation.

Mouse FT210 cells at 39 degreesC cannot enter mitosis but arrest in G2 phase, because they lack Cdc2 kinase activity as a result of a temperature-sensitive lesion in the cdc2 gene. Incubation of arrested cells with the protein phosphatase 1 and 2A inhibitor okadaic acid induces morphologically normal chromosome condensation. We now show that okadaic acid also induces two other landmark events o...

Spindle Assembly and Mitosis without Centrosomes in Parthenogenetic Sciara Embryos

In Sciara, unfertilized embryos initiate parthenogenetic development without centrosomes. By comparing these embryos with normal fertilized embryos, spindle assembly and other microtubule-based events can be examined in the presence and absence of centrosomes. In both cases, functional mitotic spindles are formed that successfully proceed through anaphase and telophase, forming two daughter nuc...

C-mitosis without colchicine in human leucocyte cultures.

Supercontracted metaphases (SMs) were investigated in cultures from four male individuals, three (case nos. 1, 3, and 4) of whom are mentally retarded patients while the fourth (case no. 2) is normal. All persons under study were characterized cytogenetically by utilizing sex chromatin incidence from buccal smears and karyo type studies. Short-term leucocyte cultures were processed according to...

The Rare Occurrence of Mitosis Without Spindle Apparatus ("Colchicine Mitosis") Producing Endopolyploidy in Embryos of the Axolotl.