Analysis of

sph^Dem/sph^Dem cDNA sequence. (A) Northern blots of total RNA from spleen (lanes 1, 2) and reticulocytes (lanes 3, 4) of +/+ (lanes 1, 3) andsph^Dem/sph^Dem(lanes 2, 4) mice. UV shadowing was used to check RNA loading. Size markers are indicated on the left. Arrow on right identifies the +/+ 8-kb transcript. (B) Schematic representation of the Spna1 cDNA with numbers above the line corresponding to the repeats of 106 aa that comprise the α-spectrin protein. Shown below the cDNA schematic is an enlargement of repeats 4 through 7 of α-spectrin, with the location of exon 11 identified. (C) α-Spectrin cDNA sequence obtained from spleen RNA of wild type (+/+) and sph^Dem/sph^Dem(Dem/Dem) mice. Shown directly below each cDNA sequence is the corresponding protein sequence. Note the lack of exon 11 sequence in the cDNA from sph^Dem/sph^Dem mice and that this deletion does not alter the translational reading frame.