Nuclear run-on transcription from primary embryonic lens tissue

Abstract

We have devised an in vitro RNA elongation assay (nuclear “run-on” transcription) that is suitable for use with small amounts of primary embryonic tissue. The assay is sensitive enough to detect transcription of single-copy genes in 8 × 10 5 nuclei isolated from embryonic chicken lens epithelia, and gives no detectable hybridization to unrelated DNAs, such as øX or pBR322. We have used this assay to examine transcription of δ-crystallin and six proto-oncogenes in lens epithelia of 6-day-old embryonic chickens. The results indicate that δ-crystallin, c- myc, p53, and c- fos are actively transcribed in these cells, while c- myb, N- ras, and c- mil are not transcribed at detectable levels.