Ciclo Celular

2012

Proliferación

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 síntesis del DNA durante el ciclo celular

MPF

El ovulo fecundado tiene algo que induce a la

mitosis

|

Se requiere del Núcleo

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 measurementshave 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

= cdc25= wee1

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 múltiples Cdk