pet Mutant and Sporulation?

AL R. PLUMMER aplummer at
Tue Mar 11 08:29:36 EST 1997

I am working with a pet mutant that fails to make cytochrome c oxidase,
but still makes cytochromes b and c/c1.  This mutant of course fails to
grow on non-fermentable carbon sources and the mutation segregates 
2:2, when crossed to a wild type strain.  This is where things get 
interesting.  When this mutant is crossed to a rho- strain, the diploids
undergo a few rounds of cell division and then stop (on synthetic medium).
These diploids do, however grow on YPD, but fail to sporulate.  At this 
point I thought that maybe the mutation also effected the mitochondrial
genome, as has been observed with other pet mutants.  This seems to be
ruled out by the tetrad analysis (2:2 segregation) and the spectral analysis 
(presence of cytochromes b and c/c1), but I do not know why the diploid
would fail to grow on non-fermentable carbon sources or why it would 
fail to sporulate.  I would think that the functional mitochondria from 
my mutant would transfer to the diploid and the functional PET gene from
the wild type would replace the defective gene.  I have tried twice,
unsuccessfully, to clone this gene and am a bit perplexed at the moment.

Has anyone had experience with anything like this and would be willing 
to discuss alternative methods to cloning this gene?  Any help would be 
greatly appreciated.

Please respond to my e-mail address in Germany:

	plummer at


More information about the Yeast mailing list