(mistake in previous message sorry!!!!)

hi guys,
does anybody knows if following of
generation of transgenic mice (and i know are transgenic) i can use them
immediately without doing characterisation i just do test such as PCR
and/or southern blot from biopsy and then if positive use them? what is exactly
the characterisation for???can i skip it??

Hi Ruth

I can't help with your question - sorry!

But, I did want to point out that it is usually considered 'bad form' to take up 2 threads on one question & sometimes people will ignore threads as they think the poster is being 'rude' or 'pushy'

I am very new here so it may be that this is done more often than in other forums & I am not writing to criticize or make you feel bad - it's not a huge deal or anything .. just a heads up for future posts :)

Good luck with your question

Ask your lab members/supervisor!

How would you know if the mouse used had the specific genotype if you hadn't genotyped it?!

Hi Ruth

I'm no expert, but seeing as nobody else here is either, my understanding is as follows: If mice are heterozygous knockouts, which is common if the gene is co-dominant or a double knockout would be lethal, you definitely have to do the PCR/southern blot on the ear punch, or whatever other sample you have because you don't know if the progeny are WT, double KO or heterozygotes. Also if the progeny ratios are skewed in one diretion or the other, this may tell you something about function.

If it's a cross between two double KO mice, where the same gene has been KO'd it probably is'nt as necessary, especially if people have published on this strain before. However if the strain is entirely novel then you must confirm that the KO has been passed on through the germ line in roughly the expected ratios. For example, it could be that your KO is embryonically lethal, so a cross between a double KO and a het would give entirely heterozygote offspring, although how you would have generated a double KO if this were the case, i don't know.

Another thing, is this a targetted KO? You can get promotor specific targettting, usually involving Cre/LoxP sequences. If this is the case you have to feed it something that will activate the targeted KO, and I would definitely check the organ of interest for expression if this is the case as you can't be sure how rapidly this KO is likely to be activated.

Regarding characterisation, surely that's the actual experiment you want to do? If you think development is affected or some behavioural characteristic, you may want to monitor the mice for a while prior to using them. I would check the literature and see if others have used this strain before, but if none of this is the case I would check the KO and use as you see fit

Hope this is of some use to you, ATB cakeman

======= Date Modified 14 Nov 2011 17:07:11 =======
============= Edited by a Moderator =============
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