GUS history? Why GUS and not lacZ?

[Mary Elizabeth Davis]

Hello - 
	I am long time Drosophila molecular geneticist without a strong 
grounding in plant molecular biology.  I have a question about the 
development of the transgenic reporter genes in plants.  As I was 
preparing for Monday's seminar in plant genomics I got to wondering why 
the GUS gene was developed for use as a plant reporter gene.  My 
recollection of this during the 80's is that the lacZ vectors were 
available and in use prior to the development of the transgenic 
technologies in plants; thus I do not know why another marker gene needed 
to be developed.  Is there a significant level of endogenous 
beta-galactosidase activity in plants, thereby requiring another gene?  
Is the E coli protein less stable in plants?  I have checked in my 
genetics texts and on the Web, but have not found an answer.  I will 
check out a plant genetics text when I am back at work, but if someone 
has an answer in the meantime, I would love to hear it.

Thanks for reading.
Mary Beth

-- 
Mary Beth Davis
		
Department of Cell and Developmental Biology
University of Pennsylvania School of Medicine
1146 BRB II/III
421 Curie Blvd.
Philadelphia, PA 19103-6058

email: davisme at mail.med.upenn.edu
tel.  215-898-0244
fax.  215-898-9871