The effect of Lyl1-KO, Pf4-Scl-KO, and Lyl1/Pf4-Scl-DKO on megakaryocyte maturation, proplatelet formation, and platelet production. (A) Lyl1-KO mice presented with a phenotype similar to that of wild-type mice. (B) Pf4-Scl-KO mice exhibited mild phenotypic differences, including a less well-developed DMS and a slight macrothrombocytopenia. (C) Lyl1/Pf4-Scl-DKO mice presented with a severe phenotype, including an abnormal vesicular DMS, reduced number of granules, prominent mitochondria, reduced proplatelet formation, and marked macrothrombocytopenia with the resulting platelets containing DMS remnants.