sph^Dem/sph^Demmice have defective dimer/tetramer complexes.

(A) SDS-PAGE of RBC ghost proteins from +/+ (lanes 1, 6) and mutant (lanes 2, 3, 4, 5) mice. Strain background and genotype of mice are indicated above each lane. Size markers indicated on left; relative positions of α-spectrin (α), ankyrin (ANK), β-spectrin (β), and band 3 (b3) indicated on right. Ratios of α, ANK, and β to b3 are listed in Table 3. (B) Immunoblot of RBC ghost proteins from +/+ (lanes 1, 6) and mutant (lanes 2, 3, 4, 5) mice. Strain background and genotype of mice are indicated above each lane. Primary antibody detects α- and β-spectrin equally. Size markers indicated on left; relative positions of α- and β-spectrin indicated on right. Arrow on right marks position of the 65-kd immunoreactive protein insph^Dem/sph^Dem mice (lane 2). (C) Representative native PAGE of 0°C low ionic strength spectrin extracts from RBC ghosts of +/+ (lane 1) and mutant (lanes 2, 3) mice stained with Coomassie Blue. Genotype of mice is indicated above each lane. Positions of spectrin dimers [D] and tetramers [T] are indicated on right. Densitometric values (in pixels): +/+[D] = 60;+/+[T] = 425; +/+[D]:[T] ratio = 0.14:1;sph^J/sph^J[D] = 11;sph^J/sph^J[T] = 109;sph^J/sph^J[D]:[T] ratio = 0.10:1. (D) SDS-PAGE of RBC ghost (lanes 1, 3, 5) and spectrin extract (lanes 2, 4, 6) proteins from +/+ (lanes 1, 2) and mutant (lanes 3-6) mice. Genotype of mice is indicated above each pair of lanes. Size markers indicated on left; positions of α- and β-spectrin indicated on right. (E) Immunoblot of RBC ghost (lanes 1, 3, 5) and spectrin extract (lanes 2, 4, 6) proteins from +/+ (lanes 1, 2) and mutant (lanes 3-6) mice. Genotype of mice is indicated above each pair of lanes. Primary antibody detects α-spectrin more efficiently than β-spectrin. Size markers indicated on left; positions of α- and β-spectrin indicated on right. Arrow on right marks 65-kd immunoreactive protein insph^Dem/sph^Dem mice (lanes 3, 4).