Fig. 2. Tissue distribution of mouse prominin-1 splice variant mRNAs. (A,B) Northern blot of poly(A)⁺ RNA (2 µg each) from various mouse tissues, analyzed first with cDNA probe E2 (A) and then with a probe for the 3'-UTR (B). (A) The membrane was exposed for 1 day (right) and 3 days (left). (B) The membrane was exposed for 3 days. RNA size markers are indicated on the left (A). (C) PCR reactions were performed using first-strand cDNA prepared from mouse tissues as template using S-TM5 and AS-T1 primers located in exons 24 and 25a, respectively. Prominin-1.s3 and s6 variant cDNAs were used as templates for positive controls (lanes s3 and s6). As a negative control, template was omitted (lane H₂O). PCR for glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression was performed as a quality control. Embryonic stages (7- to 17-day-old embryos) are indicated as E7 to E17.