Northern blot analysis of CD109-specific transcripts.

(A) KG1a cells contain multiple CD109-specific transcripts. Northern blots of KG1a total RNA probed with K1/K1-H7 common and K1-H7 specific probes are shown. The former probe is expected to detect both K1 and K1-H7 transcripts. Although 3 CD109-specific bands (11.4, 7.4, and 5.5 kb) are revealed by the common probe, the K1-H7–specific probe detects only the 2 larger transcripts. Positions of the 28S and 18S rRNA species are noted on the right. Control hypoxanthine phosphoribosyltransferase hybridizations ensure equal RNA loading. (B) CD109 is expressed widely in adult and fetal tissues. A commercial multiple tissue mRNA blot probed with a CD109 probe expected to detect both K1 and K1-H7 transcripts is shown (top panel). Corresponding RNAs are identified in the bottom panel. CD109 transcripts are detected in a wide range of tissues, with the highest levels found in adult uterus, aorta, heart, lung, trachea, and placenta, and in fetal heart, kidney, liver, spleen, and lung. In all cases, negative control RNAs and DNAs did not yield CD109-specific signals.