Fig. 6. Expression of QNR-71 in mi-expressing cells. A, Northern blot analysis of QNR-71 transcription in mi-expressing cells. Total RNA was extracted from normal QNR, QNR transfected with LE-mi (QNR-mi) or QNR transfected with the control empty vector LE (QNR-LE), as indicated at the top. QNR cells dissected from 8-day-old embryos were passaged four times (QNR P4) in vitro. A 20-µg aliquot of total RNA was hybridized with 32P-labeled QNR-71 probe encompassing the complete QNR-71 open reading frame. B, detection of QNR-71 proteins in mi-expressing cells. Normal QNR or LE-mi-transfected QNR cells were labeled with [35S]methionine/cysteine for 45 min, solubilized in 1% SDS-5% 2-mercaptoethanol-containing solution, boiled 5 min., and diluted in RIPA buffer. Cell lysates were then immunoprecipitated with a rabbit serum QNR-71 (Lanes 1 and 4) and with cognate preimmune serum (Lanes 2 and 3).