Increased frequency of mutations at A:T base pairs in the bone marrow of B6C3F1 lacl transgenic mice exposed to 1, 3-butadiene

✍ Scribed by Leslie Recio; Kathy G. Meyer

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 676 KB
• Volume: 26
• Category: Article
• ISSN: 0893-6692
• DOI: 10.1002/em.2850260102

✦ Synopsis

W e have examined the spectra of mutations in a collection of 7 4 lac1 mutants isolated from the bone marrow of B6C3F1 lac1 transgenic mice exposed to 1,250 ppm 1,3-butadiene (BD). Of the 49 inde pendent mutations analyzed in the present study, 30 of 49 (61 %) were point mutations at G:C base pairs, and 10 of 49 (20%) were point mutations at A:T base pairs. The remaining mutations consisted of small deletions and insertions and a single tandem change. An analysis of variance (ANOVA) on the frequency of specific mutations observed in each animal in this mutagenicity experiment [pres-ent study; also Sisk SC et 01. (1 994): Carcinogenesis 15:471-4771 indicated that the frequency of point mutations at A:T base pairs is significantly greater (P < 0.05) in BD-exposed mice than in the air controls. In addition, there was a decrease (P < 0.05; Fisher's exact test) in the frequency of G:C+A:T transitions at 5'-CpG-3' sites in BDexposed mice (27%) relative to air controls (51%). These data indicate that subchronic exposures to BD induces an increased frequency of in vivo mutation at A:T base pairs in the bone marrow of B6C3F1 lac/ hansgenic mice. 6 1995 Wileyliss, Inc.