Regulation of Eukaryotic cell cycle - cell bio (May/03/2005 )

hey everybody..this is one of 3 tough question I have come across while doing some preliminary work before starting my research over them summer.....could some one give a thorough and complete explanation for it( you can send it to my email at tellanish@hotmail.com...thanks a lot!

Based on your understanding of the regulation of the eucaryotic cell cycle, how could you explain each of the following experimental observations?
(a) When MPF is injected into cells that have just emerged from S phase,
chromosome condensation and nuclear envelope breakdown occur
immediately, rather than after the normal G2 delay of several hours.
( When an abnormal, indestructible form of the mitotic cyclin is introduced into
cells, they enter into mitosis but cannot emerge from it and re-enter Gl phase.
© Mutations that inactivate the main protein phosphatase used to catalyze
protein dephosphorylation cause a long delay in the reconstruction of the
nuclear envelope that normally takes place at the end of mitosis.


It's a tough question but i'm hopefuly someone can help me out

You can find the answers to these questions within a few minutes by searching the NCBI book section. I suggest you look at Cooper (The Cell - A Molecular Approach) or Lodish (Molecular Cell Biology). Answers are right there.

hey everybody..this is one of 3 tough question I have come across while doing some preliminary work before starting my research over them summer.....could some one give a thorough and complete explanation for it( you can send it to my email at tellanish@hotmail.com...thanks a lot!

Based on your understanding of the regulation of the eucaryotic cell cycle, how could you explain each of the following experimental observations?
(a) When MPF is injected into cells that have just emerged from S phase,
chromosome condensation and nuclear envelope breakdown occur
immediately, rather than after the normal G2 delay of several hours.
( When an abnormal, indestructible form of the mitotic cyclin is introduced into
cells, they enter into mitosis but cannot emerge from it and re-enter Gl phase.
© Mutations that inactivate the main protein phosphatase used to catalyze
protein dephosphorylation cause a long delay in the reconstruction of the
nuclear envelope that normally takes place at the end of mitosis.


It's a tough question but i'm hopefuly someone can help me out

I unfortunately cannot agree with you MaximinaNYC. Most textbooks such as Lodish (molecular cell biology), books from NCBI and mainstream journals would not provide you with a satisfactory answer as to how the regulation of the eucaryotic cell cycle actually works. Most of these explanations follow a reductionistic approach to explain the mechanisms involved in cell cycle regulation. Thus, because the system is not treated as a whole, many of the systemic properties of the cell cycle are lost and hence the cell cycle (as well as other metabolic and signal transduction pathways) is poorly understood.

I would recommend that tellanish (and other who are interested) to read papers on kinetic modelling of the eucaryotic cell cycle. Two scientists who are actively involved in this type of modelling of the cell cycle are John Tyson and Bela Novak.

These models consist only of ordinary differential equations and are thus very easy to construct in environments such as Mathematica, Matlab and Python. After these models are constructed they are easy and FUN to play around with and you can see how the model reacts to parameter and variable changes such as those mentioned by tellanish.

Regards.

"The aim of science is not things in themselves but the relations between things; outside these relations there is no reality knowable. "

Henri Poincare

You may be correct overall but for an undergraduate I think you need to start by reading the easy summaries and reviews offered by highly regarded texts and then go to the references .... without the basics of cell cycle biology the rest may be difficult to understand (depending on the level of the student of course which was not readily interpretable from Tellanish's question).