Expression of the 13.2-kb transgene in murine tissues.

(A) Schematic representation of the human c-fes locus. All 19 exons are indicated along with coding regions (▪), noncoding regions (■), and myeloid-cell–specific DNase I HS sites (HSa, HSb, and HSc). The positions of translational initiation and termination codons are also shown. The 5′ and 3′ EcoRI restriction sites (E) are located 0.446 kb upstream of exon 1 and 1.5 kb downstream of exon 19, respectively. Multiple transcription initiation sites occur within the first exon; +1 corresponds to the first and most prominent mRNA cap site. (B) Production ofc-fes mRNA in bone marrow obtained from multiple transgenic mice generated with the 13.2-kb EcoRI human genomic fragment depicted in panel A. Two progeny animals obtained from founder no. 3 (88 copies) in addition to founders harboring 23 and 3 copies each of the 13.2-kb construct were analyzed. Ten micrograms of total RNA were hybridized to the 372-bp human c-fes and the 314-bp murinec-fes riboprobes. The 273-bp and 288-bp protected fragments are indicated. Included as negative and positive controls, respectively, were 25 μg yeast transfer-RNA and total RNA harvested from a mouse macrophage cell line (J774.1) and a human monoblastic cell line (THP-1). (C) Production of c-fes mRNA in various tissues harvested from the same transgenic mouse analyzed in lane 1 of panel B. To control for RNA loading, 5 μg RNA were hybridized to a murine β-actin probe.