Non-nucleated Cell Longevity
Location: Outside U.S.
Country: Central African Republic
Date: Winter 2012-2913
You have a red blood cell instructed for hemoglobin and it looses its nucleus. Can a cell be fully functional without the nucleus? How long would it last and still be functional without the eventualy destruction by the spleen, etc.?
It is certainly true that red blood cells (RBCs) in mammals do not
contain nuclei, as well as most other cellular organelles. As a
result, they obviously cannot carry out many functions of a normal
cell - they cannot synthesize RNA for the production of proteins, they
cannot undergo oxidative phosphorylation in the mitochondrion to
release the most energy possible from glucose, etc. However, that
does not mean the cells are defective or non-functional. In fact,
RBCs are highly specialized cells optimized for one function -
carrying oxygen and carbon dioxide to and from the body's tissues.
They don't need most of the other cellular machinery for protein
synthesis/cell division/signalling/etc. - instead they are completely
packed full of hemoglobin and circulate through the blood stream.
Since these cells are fundamentally functional for their particular
purpose, they are not tagged by the body as 'damaged' and are thus not
immediately targeted for destruction. Most RBCs circulate in the
blood stream for 3-4 months before undergoing a process called
'senescence', where aging cells are digested and recycled by the body.
S. Unterman Ph.D.
Thanks for the question. If a eukaryotic cell ( a cell with a nucleus) loses it nucleus, the cell will be able to function for a short time. The actual time depends on many factors, such as protein and enzyme content, amount of intracellular messengers, etc. Some types of stem cell therapy depend on the ability of a cell to remain alive until a new nucleus is inserted into it.
A red blood cell has a life of around 60 days (if I recall correctly) before it is removed by the spleen.
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Update: November 2011