title: Cytopenia induction by 5-fluorouracil identifies thrombopoietic mutants in sensitized ENU mutagenesis screens.
abstract: The ability of random mutagenesis techniques to annotate the mammalian genome can be hampered due to genetic redundancy and compensatory pathways that mask heterozygous mutations under homeostatic conditions. The objective of this study was to devise a pharmacologically sensitized screen using the chemotherapeutic drug, 5-fluorouracil (5FU), to induce cytopenia. 5FU dose was optimized in the 129/SvImJ, C57BL/6J, BALB/cJ, and C3H/HeJ strains of laboratory mice. N-ethyl-N-nitrosourea (ENU) mutagenesis was performed on 129/SvImJ males and phenotypic variants were identified by backcrossing on to the C57BL/6J background. G1 animals were challenged with 100 μg/g 5FU and phenodeviants with altered platelet recovery were monitored. Of 546 G1 animals tested, 15 phenodeviants were identified that displayed increased baseline platelet number, a platelet overshoot, or delayed platelet recovery, thereby demonstrating the utility of this approach for uncovering mutations in megakaryocyte and platelet development. Four G1 mice were selected for further analysis. The phenotypes were heritable in all four strains and genetic mapping identified a chromosome location in two of the three G2 lines tested. In conclusion, our group has developed a sensitized random mutagenesis screen utilizing 5FU and has shown that the strain combination of 129/SvImJ × C57BL/6J is robust for identification of founder lines with defects in megakaryocyte and platelet development.
authors.affiliation: Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ont, Canada.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Anderson
authors.forename: Zorana
authors.initials: Z
authors.lastname: Berberovic
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Berndl
authors.forename: Monica L
authors.initials: ML
authors.lastname: Bailey
authors.forename: Ann M
authors.initials: AM
authors.lastname: Flenniken
authors.forename: Lucy R
authors.initials: LR
authors.lastname: Osborne
authors.forename: S Lee
authors.initials: SL
authors.lastname: Adamson
authors.forename: Janet
authors.initials: J
authors.lastname: Rossant
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Mark D
authors.initials: MD
authors.lastname: Minden
authors.forename: Kelly M
authors.initials: KM
authors.lastname: McNagny
authors.forename: Robert F
authors.initials: RF
authors.lastname: Paulson
authors.forename: Dwayne L
authors.initials: DL
authors.lastname: Barber
authors.forename: William L
authors.initials: WL
authors.lastname: Stanford
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D005038:Ethylnitrosourea / Q000494:pharmacology*; D005260:Female; D005472:Fluorouracil / Q000494:pharmacology*; D008297:Male; D051379:Mice; D057507:Mice, 129 Strain; D020297:Mice, Congenic; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D016296:Mutagenesis / Q000187:drug effects* / Q000235:genetics; D009154:Mutation / Q000235:genetics*; D013921:Thrombocytopenia / Q000139:chemically induced*; D034061:Thrombopoiesis / Q000187:drug effects / Q000235:genetics*
chemical_list: D000970:Antineoplastic Agents; D005038:Ethylnitrosourea; D005472:Fluorouracil