title: Chromosome instability and tumor predisposition inversely correlate with BLM protein levels.
abstract: Independent mouse models for Bloom syndrome (BS) exist, each thought to disrupt Blm gene function. However, animals bearing these alleles exhibit distinct phenotypes. Blm(tm1Ches) and Blm(tm1Grdn) homozygous mutant animals exhibit embryonic lethality while in another, Blm(tm3Brd), homozygosity yields viable, fertile animals with a cancer predisposition. Further characterization reveals the Blm(tm3Brd) allele to be a hypomorph, producing a diminished quantity of normal mRNA and protein. The Blm(tm3Brd) allele produces sufficient normal protein to rescue Blm(tm1Ches) lethality. Evaluation of viable animals reveals an inverse correlation between the quantity of Blm protein and the level of chromosome instability and a similar genotypic relationship for tumor predisposition indicating that Blm protein is rate limiting for maintaining genomic stability and the avoidance of tumors.
authors.affiliation: Department of Pathology, CY1.107, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-8840, USA.
authors.forename: Lisa D
authors.initials: LD
authors.lastname: McDaniel
authors.forename: Nicholas
authors.initials: N
authors.lastname: Chester
authors.forename: Mark
authors.initials: M
authors.lastname: Watson
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Borowsky
authors.forename: Philip
authors.initials: P
authors.lastname: Leder
authors.forename: Roger A
authors.initials: RA
authors.lastname: Schultz
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001816:Bloom Syndrome / Q000235:genetics*; D043171:Chromosomal Instability; D004265:DNA Helicases / Q000378:metabolism*; D020964:Embryo Loss / Q000235:genetics; D005314:Embryonic and Fetal Development / Q000235:genetics*; D005260:Female; D018390:Gene Targeting; D020022:Genetic Predisposition to Disease; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009369:Neoplasms / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D053484:RecQ Helicases; D013154:Spleen / Q000378:metabolism; D013489:Suppression, Genetic
chemical_list: D012333:RNA, Messenger; D000251:Adenosine Triphosphatases; C097151:Bloom syndrome protein; D004265:DNA Helicases; D053484:RecQ Helicases