FIGURE 4.
Gene expression in the Dlk1-Dio3 domain. A, graphical representations of the expression levels of the five imprinted genes Dlk1, Gtl2, Rian, Mirg, and Dio3 at E18.5. The values are expressed as the means ± S.E. Wild-type, n = 4, yellow; IG-DMR(−/+), n = 4, red; Gtl2(+/−), n = 3, blue; and IG-DMR(−/+)/Gtl2(+/−), n = 5, green. It is normalized to 1 in each tissue, which represents the average expression level of the WT. The expression value of Rian and Mirg in the IG-DMR(−/+)/Gtl2(+/−) double mutants was individually indicated by dots because the expression was varied among samples. B, Northern blot analysis of Rtl1 expression at E18.5. B, brain; T, tongue; Lu, lungs; Li, liver; and P, placenta. Glyceraldehyde-3-phosphate dehydrogenase (Gapdh) was used as control. For comparison of the date, statistical analyses were carried out with one-way analysis of variance. The superscripts denote the differences (p < 0.05) between the genotype means. W, wild-type; I, IG-DMR(−/+); G, Gtl2(+/−); D, IG-DMR(−/+)/Gtl2(+/−).