Minigene analyses of ankyrin mRNA splicing. Wild-type and mutant ankyrinAnkara minigenes from exon 15 to exon 20 were prepared and transfected into COS and K562 cells. The sequence of the RT-PCR products derived from RNA of transfected cells was analyzed. RNA from cells transfected with the wild-type minigene contained the expected normally sized and spliced product (wild-type [WT], top line). RT-PCR products derived from RNA of cells transfected with the mutant ankyrinAnkara minigene yielded 11 mutant spliceoforms, shown schematically, but no wild-type product. Similar studies with reticulocyte RNA from the proband yielded the same results, except that the +26-bp and +144-bp spliceoforms were not found.