Cell Cycle and Apoptosis
1. Taxol its generic name being palitaxel stabilises cytoskeletal microtubes and thus spindles cannot be formed so cell division is prevented. During telophase taxol causes the reversal of prophase events such as the chromosomes decondense, spindle disassembly, nuclear envelope reformation, the Golgi apparatus and E.R. reform and the nucleus also reforms. Cytokinesis effects are that the cell still divides for animal cells a cleavage furrow made of actin and myosin II constricts the middle of the cell and in plants the phragmoplast forms at the equator of the spindles where a new cell wall forms
2. Using Taxol which affects the spindle formation the cell would have already undergone metaphase and anaphase. This means that taxol can be used to examine processes during the cell cycle. Taxol can also be used to examine inhibitory proteins and antimitotics and their effects on the cell cycle as well.
3. The Aim of such experiment was to determine what causes the cell to undergo cytoplasmic changes to undergo mitotic division. For this mammalian cells in various stages of the cell cycle S, G1, G2 and M were fused together in various combinations and the nucleus interaction was noted. Combinations were done in pairs such as S + G1, S + G2, G1 + G2 and G2 + M. Through these interactions it was realised that cells must complete a certain cell cycle before it can carry out another. The most interesting realization is that M phase and G2 fusion caused G2 to enter mitosis. When unfertilised Xenopus oocytes were injected into interphase oocytes there were similar results obtained. This meant that in the cytoplasm of dividing cells a factor controlled entry to mitosis and the activity was called the M-phase controlling factor.
4. The G1/S control point is determined by three cyclindependent kinases (Cdk2, Cdk4 and Cdk6). Cyclin D partners with Cdk4 and Cdk6 to allow them to enter a high efficiency state and Cyclin E partners with Cdk2. Cdk4 for example
2. Using Taxol which affects the spindle formation the cell would have already undergone metaphase and anaphase. This means that taxol can be used to examine processes during the cell cycle. Taxol can also be used to examine inhibitory proteins and antimitotics and their effects on the cell cycle as well.
3. The Aim of such experiment was to determine what causes the cell to undergo cytoplasmic changes to undergo mitotic division. For this mammalian cells in various stages of the cell cycle S, G1, G2 and M were fused together in various combinations and the nucleus interaction was noted. Combinations were done in pairs such as S + G1, S + G2, G1 + G2 and G2 + M. Through these interactions it was realised that cells must complete a certain cell cycle before it can carry out another. The most interesting realization is that M phase and G2 fusion caused G2 to enter mitosis. When unfertilised Xenopus oocytes were injected into interphase oocytes there were similar results obtained. This meant that in the cytoplasm of dividing cells a factor controlled entry to mitosis and the activity was called the M-phase controlling factor.
4. The G1/S control point is determined by three cyclindependent kinases (Cdk2, Cdk4 and Cdk6). Cyclin D partners with Cdk4 and Cdk6 to allow them to enter a high efficiency state and Cyclin E partners with Cdk2. Cdk4 for example