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* at sbsu1 * at sbsu1.auckland.ac.nz
Fri Oct 6 05:40:29 EST 1995

>Dear net readers,
>I am looking for information on sporulation of a strain directly derived from
>s288c - this diploid strain seems to sporulate to give almost entirely
>three spored tetrads.  I obtained the strain by mating the FY833 and FY834
>strains, and it is WT apart from the common markers.  I am wondering if
>this incomplete sporulation occurs normally in some strain backgrounds, or
>if I'm responsible in some way.  I've been using straight KAc plates with
>Colin MacDiarmid
>Plant Science, University of Auckland.
>macdiarm at sbsu1.auckland.ac.nz

Thanks to those who replied to my question.  A suggestion from Michael Lichen
is included below;

1. Try room temperature.  It often improves sporulation.  I found with
S288c that I could get a tolerable number of 4-spored ascii (still had to
look for em, though) when I left the sporulation plates on the benchtop.

2. I got best results when I replica-plated a one day old patch on YPD onto
the following plates:

20 gm/l pottasium acetate
2.2 gm/l yeast extract
0.5 gm/l glucose
0.87 gm/l complete aa + nucleotides mixture. (I can send recipe if you
want, but any standard complete mix should do)
20 gm/l bacto agar.

If this doesn't work, you can also try what we called "super KAc" plates,
which are basically the above, but with 2 gm/l yeast extract, 4 gm/l
peptone, and 4 gm/l glucose. The idea behind these plates is to get the
diploids growing and healthy, and then have them ease into starvation as
they exhaust the glucose, etc.  It takes longer to get ascii on these
plates, and they are always contaminated with vegetative cells, but the
yield of spores/ascus may be higher.

Michael Lichten
lichten at helix.nih.gov

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