Splenomegaly and modified erythropoiesis in KLF13-/- mice.

To study the function of the Krüppel-like transcription factor KLF13 in vivo, we generated mice with a disrupted Klf13 allele. Although Klf13(-/-) mice are viable, fewer mice were present at 3 weeks than predicted by Mendelian inheritance. Viable Klf13(-/-) mice had reduced numbers of circulating erythrocytes and a larger spleen. The spleen contained an increased number of Ter119(med)CD71(hi), Ter119(hi)CD71(hi), and Ter119(hi)CD71(med) cells but not Ter119(hi)CD71(-) cells, indicating an increase in less mature erythroblasts. A higher proportion of the Ter119(med)CD71(hi) cells were proliferating, indicating that the mice were under a degree of erythropoietic stress. These data indicate that KLF13 is involved in the normal control of erythropoiesis.