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Ciclo Celular 2012


Proliferaci贸n


Dos fases

Fase M o mitosis Intrefase


Ciclo Celular

Proceso ordenado Celulas Proliferantes G0 estado no proliferativo


Marcando con timidina tritiada es posible seguir la sĂ­ntesis del DNA durante el ciclo celular


MPF


El ovulo fecundado tiene algo que induce a la mitosis


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Se requiere del NĂşcleo


Actividad MPF se asocia a ciclina

Figure 17-19. Rise and fall in levels of MPF and cyclin during the early embryonic cell cycle. The cyclin measurements have been made chiefly in the eggs of marine invertebrates, where cyclin accounts for 5% of the protein synthesized during a brief pulse with radioactive amino acids. The gels below the graph show the amounts of labeled cyclin of two varieties, A and B, at different stages of the cycle of a clam egg. The bottom line in the gel shows the synthesis of a house-keeping enzyme that serves as a standard of comparison. (Adapted from T. Hunt, F.C. Luca, and J.V. Ruderman, J. Cell Biol. 116:707-724, 1992.)


El modelo de regulacion del ciclo celular


El motor del ciclo es la dupla ciclina – quinasa dependiente de ciclina (cdk)


El ciclo celular es regulado por complejos ciclina-quinasa dependiente de ciclina


Modelo levadura


Mutante petite


Diploide


Mutantes de levadura = wee1

= cdc25


Figure 17-30. The Cdc2 cycle in yeast. Cdc2 is permanently present, but its state of association with cyclins changes, definingthe division-cycle phase of the cell.


Especificidad


Vertebrados mĂşltiples Cdk



Clases de cICLO CELULAR i