MadSci Network: Cell Biology

Re: For cloning, do you need just stem cells, or can you use other cells?

Date: Mon May 21 10:38:11 2001
Posted By: Paul Szauter, Staff, Mouse Genome Informatics, The Jackson Laboratory
Area of science: Cell Biology
ID: 990212025.Cb

It is not necessary to use the nuclei of stem cells for the cloning of 

For the most part, all of the cells in an adult mammal are genetically 
equivalent, which is to say that they contain the exact same set of DNA 
sequences that was present in the fertilized egg. The differences between a 
nerve cell, a muscle cell, a skin cell, and so on, are due to differences in 
the genes that are expressed, not differences in the genes that are present. 
This is evident from the cloning of mice from differentiated cells like 
neurons; the cloned mice have all cell types, and are not merely a bundle of 

The exception to this general rule is that some cells of the immune system 
undergo DNA rearrangements to generate new antibody types; the DNA of these 
cells is no longer equivalent to that of the fertilized egg.

It is actually more important to use cells that are at the right part of the 
cell cycle. The 'cell cycle' is the series of events that cells go through 
when they grow and divide. You are probably familiar with mitosis, the 
dramatic series of events that partitions replicated chromosomes into the 
two daughter cells. Mitosis occurs during M phase of the cell cycle. Another 
phase of obvious activity is S phase, during which DNA replication occurs (S 
is for 'synthetic'). Two other phases are 'gap' phases, during which it is 
not apparent that the cell is doing very much: G1 and G2. The series of the 
phases is: G1, S, G2, M.

You can read more about the cell cycle at:

There is another state that cells can exist in (G0) when they are no longer 
going to divide. Cells enter G0 following the last M phase and then just 
live out their lives, never dividing again. For the cloning of mice, it was 
found to be important to use nuclei from G0 cells. Nuclei from Sertoli 
cells, neuronal cells, and cumulus cells were used successfully. About 90% 
of cumulus cells that surround recently ovulated oocytes are in G1/G0. 
Sertoli cells and neurons do not normally divide in adults, so they are in 

A good paper to read about mouse cloning is:

Wakayama T, Perry AC, Zuccotti M, Johnson KR, Yanagimachi R Full-term 
development of mice from enucleated oocytes injected with cumulus cell 
nuclei. Nature 1998 394:369-74

You might find this glossary useful in reading this answer:

Thank you for an interesting question.


Paul Szauter
Mouse Genome Informatics

Current Queue | Current Queue for Cell Biology | Cell Biology archives

Try the links in the MadSci Library for more information on Cell Biology.

MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci

MadSci Network,
© 1995-2001. All rights reserved.