[Ylide (OP)]

What are the pathological consequences of a deficiency in cyclin for mitotic cells?  

I understand the consequence of an excess is uncontrolled cellular reproduction which can lead to cancer, but what about the opposite?

This message brought to you by The Council of People Who Are Sick of Seeing More People

[chris]

Some forms of anaemia arise because the bone marrow is turning over too slowly (aplastic anaemia), although this is usually due to a toxin or post-infection.

Hypothyroidism causes a generalised reduction in metabolic rate which translates into poor skin, hair and nails because of poor cellular turnover, but this is more of a generalised effect.

Interesting question though !

Chris

"I never forget a face, but in your case I'll make an exception"
 - Groucho Marx

[Ylide (OP)]

Thanks for the answer, Chris.  My genetics prof. had no idea what the results would be other than a slow rate of cellular division.



This message brought to you by The Council of People Who Are Sick of Seeing More People

[MayoFlyFarmer]

Well I think you have the obvious answer there (a slow rate of cellular division).  the real question is what circumstances would come about from that?  This depends on a lot of factors.  Such as if the deficiency is localized or organism-wide.  Also the state of development.  The obvious things that come to mind are a slowed growth rate/higher degeneration rate (because remember there is always a ratio to consider between the rate of division and the rate of apoptosis.  But the most noticable and detrimental consequences would probably come in systems that need short bursts of high division (such as the immune system)

Yar, the flies be everywhere!!!

[alastair84]

i duuno....at a wild guess maybe stop the cell entering different phases? e.g. s, g1, g2? as cyclin-dependent kinases control the checkpoints that prevent entry into the next phase of cell cycle. just a guess.

[Rokitansky]

My opinion, partly based on the discusion above is that there are no consequences!
Weel, if a cell mutate in the way it can`t enter the next phase of it`s cell cycle, it will either enter the apoptosis, or stop to divide. Either case, healthy cells will continue to proliferate, and there will be no loss of function.
(If the case of sistemic disorder, there would be problems for the organism, but i can`t think any cause that could lead to this.)

[Ylide (OP)]

I'm thinking it would arrest the cell cycle.  In the case of cells where constant cellular reproduction is needed (gametes, blood cells) this could eventually cause failure of that system leading to infertility, compromised immune system, anemia.  Sound plausible?



This message brought to you by The Council of People Who Are Sick of Seeing More People

[Rokitansky]

Yes, but it would have to affect ALL or most of the cells in the system. If congenital, this anomaly would lead to a loss of a fetus.