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Fig. 5. Microinjected U3 and U65 snoRNAs are retained within the nucleus and
localized to nucleoli of Xenopus oocytes after injection of T24N Ran.
(A,C) Recombinant RanT24N in microinjection buffer (bottom panels) or
microinjection buffer alone (top panels) were injected into separate sets of
oocytes. One hour later, one fmole of fluorescently and 32P-labeled
U3 or U65 snoRNA was injected into the same set of oocytes. Nuclear spreads
were made four hours after injection of the RNA, and slides were analyzed by
fluorescence microscopy. Several individual nucleoli are shown in each
differential interference contrast (DIC) panel. The fluorescence signals (RNA)
show that the injected snoRNAs are targeted to a centrally located subregion
of the nucleoli in oocytes, which were injected with the T24N Ran (+T24N).
(B,D) Nuclear (N) and cytoplasmic (C) fractions were obtained from the same
set of injected cells. RNA was extracted from the N and C fractions and
subjected to denaturing PAGE followed by autoradiography. The marker lane (M)
indicate samples prior to injection.