Differential transcription of the repetitive R-element in various mouse cell types

Clones that contain R-elements separated from the rest of the L1-repeat have been isolated from a mouse genomic DNA library. Spot hybridization of DNA from various species (from mammals to plants) with one representative and well characterized mouse DNA clone shows that at least this sequence hybridizes only with mouse DNA. In addition, we demonstrate that the R-element repeat is transcribed differentially in various tissues or cell types. Furthermore, the amount of R-transcripts is regulated at varying rates in the different cell types of a tissue as shown by in situ hybridization.