The 0.5-kb HSabc construct contains the locus control region.

(A) Ten micrograms of the indicated RNAs were separately analyzed by RPA. The tissues were collected from the bone marrow of an 88-copy-number 13.2-kb transgenic mouse (lane 1) and 2 founders containing the 0.5-kb HSabc construct (lanes 2-11). RNA from the 13.2-kb animal protected a human c-fes fragment of 273 bp, and the other RNAs protected a 180-bp fragment. Autoradiography was performed for various times to ease comparison between RPAs of mouse and human transcripts. (B) RPAs performed on splenic RNA samples derived from multiple transgenic mice. Total RNA harvested from the indicated founder strains was analyzed by means of the previously described riboprobes for human and murine c-fes transcripts. The designated number for each transgenic line is indicated so that these assays can be compared with the data presented in Table1.