FIG. 4.

Expression of claudin-18 transcripts. (A) Northern blot analysis using exon-specific probes in adult mouse lung and stomach. Ten micrograms of total RNA from the indicated tissues was consecutively hybridized with each probe shown on the right. (B) Dot blot analysis of claudin-18 mRNA in human tissues. RNA sources are as follows: A1, whole brain; A2, amygdala; A3, caudate nucleus; A4, cerebellum; A5, cerebral cortex; A6, frontal lobe; A7, hippocampus; A8, medulla oblongata; B1, occipital lobe; B2, putamen; B3, substantia nigra; B4, temporal lobe; B5, thalamus; B6, subthalamic nucleus; B7, spinal cord; C1, heart; C2, aorta; C3, skeletal muscle; C4, colon; C5, bladder; C6, uterus; C7, prostate; C8, stomach; D1, testis; D2, ovary; D3, pancreas; D4, pituitary gland; D5, adrenal gland; D6, thyroid gland; D7, salivary gland; D8, mammary gland; E1, kidney; E2, liver; E3, small intestine; E4, spleen; E5, thymus; E6, peripheral leukocyte; E7, lymph node; E8, bone marrow; F1, appendix; F2, lung; F3, trachea; F4, placenta; G1, fetal brain; G2, fetal heart; G3, fetal kidney; G4, fetal liver; G5, fetal spleen; G6, fetal thymus; and G7, fetal lung. (C) Differential expression of claudin mRNAs in wild-type and T/ebp/Nkx2.1-null embryo lungs. Total RNAs prepared from E12.5 embryonic lungs of wild-type (WT) or T/ebp/Nkx2.1-null mutant (−/−) mice were analyzed by RT-PCR using various claudin primers as indicated. Primer pair P1-P2 (shown in Fig. 1) was used for claudin-18a1.