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Fig. 5. A shift-back protocol facilitates the detection of ribosome biogenesis
defects. (A) 5' ITS1 was localized in xrn1
, nic96-1
xrn1
, and kap104-16 xrn1
after shifting to
37°C for 3 hours (b,f,j, respectively) or shifting back from 37°C to
25°C for 30 minutes (d,h,l). Chromosomal DNA was labeled with DAPI
(a,c,e,g,i,k). (B) pre-rRNA processing in wild-type (lanes 1-6) and
nic96-1 (lanes 7-12) cells shifted to 37°C or shifted-back to
25°C. Cells were pulse labeled for 3 minutes and chased for 0,3 or 10
minutes. RNA was extracted and run on a formaldehyde-agarose gel. Sizes of the
rRNAs are indicated.