Map of the 5′ region of the human β3 gene. (A) Southern blot data from Fig 2 were used to generate the map of the 5′ region of the β3 gene. The previously isolated sequences by Villa-Garcia et al30 and Zimrin et al29 are indicated above. Sp, Spe I; X, Xho I; P, Pst I; R, EcoRI; M, Mlu I; and K, Kpn I. The Pst I site with an asterisk is based on the data in Fig 2C. Underlined enzymes indicate clusters of sites. Exons 0 through 4 are indicated as black boxes; probe locations are indicated by small open boxes and labeled ex0.S, int0, and ex2.A. Gaps and dots in horizontal line indicate portions that have not been sequenced; dots represent new information from the current study. It is not known whether additional Pst I, Spe I, or EcoRI sites are contained within the dotted region. (B) Long-range restriction map for the β3 gene. D12 was digested with Sfi I (S) and/or Not I (N), and pulsed-field gel and Southern blot analyses were performed with probes synthesized from the sequences at the SP6 and T7 ends of the P1 plasmid. The entire D12 insert is shown as the horizontal line. Probe ex13 was a 1.5-kb cDNA 3′ to the EcoRI site in exon 13.36 The 5′ ex2.A and 3′ ex13 probes are positioned in the approximate location of the appropriate exon. Numbers are kilobases between indicated restriction sites. The horizontal line with arrow indicates the extent of the β3 gene.
