The Men ε/β locus produces two non-coding RNAs. (A) The Men ε/β ncRNAs are transcribed from a single promoter located on mouse chromosome 19qA. Men ε is highly conserved among mammals and does not contain any repetitive elements. (Arrows) Transcription start site and polyadenylation site. (Black box) Northern and (▲) RNase protection assay (RPA) probe positions. The position of the primer pairs used in the Q-PCR (Fig. 1C) is indicated. The 3′-UTR of a nearby protein coding gene is located ∼6 kb upstream of the transcription start site. (B) Northern blot analysis using 10 μg of total RNA from 8-wk-old C57BL6 mice. (Arrow) A single band of ∼3.2 kb was detected using a probe complementary to the Men ε transcript. Relative levels of Men ε in various tissues are depicted as a histogram. Beta-actin (also known as Actb) was used as a loading control. (C) An RNase protection assay was performed using 10 μg of total RNA from the same mice. Relative levels of Men β in various tissues are depicted as a histogram. Beta-actin was used as a loading control. The full-length beta-actin probe and Men β probe are 304 nt and 221 nt, respectively. (Arrow) The protected MEN β fragment is 201 nt. (Arrowheads) Protected beta-actin fragments, 245-nt major fragment, and two smaller muscle-specific fragments.