MadSci Network: Genetics

Re: What is the difference between the transgenic animal and cloned animal?

Date: Sun Apr 7 00:09:45 2002
Posted By: Luke Collyer, Graduate Student, Biochemistry & Molecular Biology, Monash University
Area of science: Genetics
ID: 1012962492.Ge

Greetings Xu. 

Sorry it has taken me so long to reply to your question. The terms 
transgenic and cloned have quite different meanings. 

Transgenic is a word usually used to describe an animal (or plant, or 
perhaps another organism) that has had one or more genes from another cell 
or organism stably incorporated into its own genome, and is capable of 
passing on these "foreign" genes on to daughter cells. Therefore a 
transgenic mouse for example, may have a foreign gene construct stably 
incorporated into its own DNA, causing the expression of that foreign gene 
in cells and tissues that it may not otherwise be expressed in. Further, 
the expression level of the foreign gene in the transgenic organism is 
generally different from the levels in which the original gene is expressed 
in the host cell/organism. Creating transgenic mice that overexpress (or 
underexpress) a given gene can be very useful for studying its function. 
Another term, knockout, is used to describe organisms that have a given 
gene inactivated (no gene expression). These are also very useful for 
studying the function of a given gene. 

A cloned animal on the other hand is an organism that is genetically 
identical to the original organism from which it was derived. A famous 
example of the latter is Dolly, the lamb cloned from an adult sheep udder 
cell. Interestingly, as I was writing this reply I was informed by a 
colleague that an Italian fertility specialist has just claimed that one of 
his patients is pregnant with the worlds first cloned baby. I am not sure 
how true this claim is, but the following link is to a news report I found 
on the issue - 

I hope this is helpful. 


Current Queue | Current Queue for Genetics | Genetics archives

Try the links in the MadSci Library for more information on Genetics.

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

MadSci Network,
© 1995-2002. All rights reserved.