Figure 2.

Binding of the CP190 variants to polytene chromosomes. (A) Schematic representation of the CP190 variants. The expression vector is shown above: the Ubi-p63E promoter with its 5′UTR and 3′UTR from the dCTCF gene fused with the SV40 region including polyadenylation signals. The intronless yellow gene (not to scale) was used as a reporter. Below are shown the full-length schemes of the CP190^WT-F coding region and the N-terminal regions of the CP190^hK–F, CP190^Δ210–245–F, and CP190^Δ309–390–F derivatives. Other designations are as in Figure 1. Cytological localization (B) of CP190, dCTCF, and Su(Hw) and (C) CP190 and M1BP proteins on the polytene chromosomes of the Ubi:CP190*/CyO; Cp190²/Cp190³ lines, where Ubi:CP190* is either Ubi:CP190^WT(WT), Ubi:CP190^hK(hK), Ubi: CP190^Δ210–245(Δ210–245), or Ubi:CP190^Δ309–373(Δ309–373). CP190⁻ represents the Cp190²/Cp190³ mutant line. The panels show the immunostaining using (B) anti-Su(Hw) (red), mouse anti-dCTCF (magenta), and rat anti-CP190 (green) antibodies, and (C) the rat anti-CP190 (green) and rabbit anti-M1BP (red) antibodies. Arrows indicate sites of protein colocalization. DAPI staining of polytene chromosome squashes is represented in blue. Scale bars, 10 μm.