Fig. 1.

The Plt13 mutation affects the translation initiation codon of Gata-1. (A) The PLT13 founder (G₁, arrow) was identified because of a low platelet count (495 × 10⁶ per milliliter) and bred to test the heritability of the phenotype. G₂ mice that displayed a reduced platelet count (filled circles) were selected for breeding, and data from their offspring (G₃) were separated by sex to demonstrate that the phenotype was X-linked. Platelet counts from G₃ mice were tabulated (mean ± SD), and mice that had a platelet count <800 × 10⁶ per milliliter were considered affected. (B) DNA sequence from exon 2 of Gata-1 is shown for wild-type (Gata-1^+/+) and affected (Gata-1^Plt13/+ and Gata-1^Plt13/Y) animals. The translation initiation codon of Gata-1 is underlined. (C) 293T cells were transfected with expression constructs for wild-type Gata-1 (WT), Gata-1^Plt13 (PLT13), or vector alone (V). Lysates were separated by SDS/PAGE, and a Western blot was performed with an antibody that recognizes the C terminus of Gata-1. Filled circles mark full-length Gata-1, and an open circle marks truncated Gata-1.