Increased incidence of MMLV-induced lymphomas in Eed mutant mice. (A) Schematic representation of the experimental design. (B) Survival curves showing increased incidence of MMLV-induced tumors in Eed^hypo/+ and Eed^hypo/hypo mutant mice compared with control littermates. (C) Presence of both Eed^hypo mutant and wild-type alleles in MMLV-induced Eed^hypo/+ tumors. Top shows the hypomorph T > A point mutation at position 1031 of Eed. Bar graphs show the number of clones sequenced, containing the Eed^hypo or wild-type allele, per Eed^hypo/+ tumor. Clones were obtained by amplifying the Eed gene from DNA (middle) or RNA (cDNA; bottom) extracted from heterozygous tumors. (D) Wright-Giemsa stainings of representative cytologic preparations of T and B lymphomas and their healthy counterparts from wild-type and Eed mutant mice. *No healthy lymph node preparations could be obtained.