GUS expression

caspart at esvax.dnet.dupont.com caspart at esvax.dnet.dupont.com
Mon Jun 6 17:32:57 EST 1994


In Article <9406011921.AA22224 at mendel.Berkeley.EDU>
"williams at MENDEL.BERKELEY.EDU" says:
> Re: Thoma et al. Plant Physiology 105:35-45 (1994) and Uknes et al. Plant
> Cell 5: 159-169.
>
>         In the first paper the authors describe  a lipid transfer protein
> promoter/GUS fusions in transgenic Arabidopsis. GUS activity appears in the
> pollen but the LTP mRNA does not. In the second paper a similar result was
> found with the PR-1a promoter in tobacco. There the authors also tested a
> second reporter gene and found no activity in tobacco, suggesting that the
> ectopic expression was caused by the GUS coding sequences.
>
> I wonder how prevelant ectopic GUS expression in pollen really is? I assume
> the following to be true:
>         *there is no GUS activity in pollen of untransformed plants
>         *there is no GUS activity in pollen of plants transformed with
> pBI101  (poly-linker fused to GUS with nos 3')
>         *most constructs introduced into plants do not promote GUS
> expression in pollen
>
>   I would appreciate hearing from anyone who has detected GUS expression in
> pollen and whether they looked for the endogenous gene in pollen by in situ
> hybridization. Also, has anyone looked into whether the GUS gene effect is
> transcriptional or post-transcriptional? I guess I'm confused because
> ectopic expression in pollen is not found in all transgenics (I assume),
> and most of the reports of pollen specific expression are backed up by in
> situ or northern data. Love to hear from any interested parties!
>
> Mary Williams (Sussex lab)
>
I haven't looked at the background GUS expression in pollen carefully, but
I have a line transformed with a promoterless-GUS construct which might
be helpful as a control in these types of studies.  I have just sent
it off to the OSU stock center.  
Tim Caspar
Dupont Central Research
caspart at esvax.dnet.dupont.com



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