Proviral structure, integration, and expression in MSCVMLL-ELL mice.
(A) Structure of the MSCVMLL-ELL retrovirus. Indicated
are the diagnostic NheI, BamHI, and
NcoI restriction endonuclease recognition sites that
permit assessment of provirus integrity and copy number. PGK,
phosphoglycerate kinase. (B) Southern blot analysis of
NheI-digested genomic DNA with an MLL probe showing that
leukemic spleens from MSCVMLL-ELL mice harbor nonrearranged (8.8-kb
NheI band indicated by arrow) proviruses. The 10-kb
fragment is representative of the endogenous
MLL gene. At left is sizes (in kb) of the molecular
weight standards. (C) Expression by reverse
transcription–PCR of retroviral-derived MLL-ELL.
Expression was studied in a negative control cell line (32D),
MLL-ELL-transduced BM, a cell line derived from the
leukemic BM of mouse #4 as well as in spleen from leukemic mice (spleen
from mice #1 and #4 are shown), or from a control normal mouse.