The objective of this research is to study chemical mutagenesis at the DNA level in mammals and to evaluate genetic and biochemical events in certain mutants as models of human genetic diseases. A major problem in mutagenesis is that the level and specificity of response is very different between indicator organisms; predictions about induced mutagenesis may not be relevant. Significant variation is due to the diversity of the marker genes; a single sequence needs to be used as a target in the various organisms and tissues. Our analysis is based on variance among single copies of the phi X174 virus containing am3 and cs70 mutations as a shuttle vector in different species. The accomplishments are as follows: 1) Techniques have been developed to recover chromosomally integrated phi X DNA and produce sufficient viable phages for the study of mutagenesis in cultures or tissues of transgenic mice. 2) The reversion frequency of am3 has been measured in progeny phage rescued from untreated mouse L-cells (5 X 10-), and cells treated with 20mM EMS (1.16 X 10-5). 3) New cell lines containing phi X have been produced. 4) Experiments are in progress to expand the indicator region of the phi X phage to provide detection of many more mutations in the integrated phage DNA. The use of integrated viral vector in transgenic mice can combine a theoretical study of mechanisms of mutation in several model organisms with an assessment of mutagenic hazard. A single DNA sequence can be exposed and analyzed as naked DNA, as a single stranded virus, double stranded in bacteria, and as vector DNA in the nuclear genome of mammalian cells or transgenic mice. In addition, we have characterized a new genetic mouse biochemical model of transient neonatal jaundice as a unique UDP-glucuronyl transferase deficiency. Adults homozygous for the mutation appear phenotypically normal in terms of the jaundice but remain enzymatically deficient throughout life. The enzymatic deficiency is accompanied by generalized necrosis and liver enlargement in older mutants. Work is in progress to determine whether the mutation is in the structural gene or perhaps regulatory.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Intramural Research (Z01)
Project #
1Z01ES065033-06
Application #
3918723
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
6
Fiscal Year
1988
Total Cost
Indirect Cost
Name
U.S. National Inst of Environ Hlth Scis
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Samet, Jonathan M; DeMarini, David M; Malling, Heinrich V (2004) Biomedicine. Do airborne particles induce heritable mutations? Science 304:971-2
Weaver, Robert P; Malling, Heinrich V (2003) The in vivo but not the in vitro am3 revertant frequencies increase linearly with increased ethylnitrosourea doses in spleen of mice transgenic for phiX174 am3, cs70 using the single burst assay. Mutat Res 534:1-13
Valentine, Carrie R; Montgomery, Beverly A; Miller, Scott G et al. (2002) Characterization of mutant spectra generated by a forward mutational assay for gene A of Phi X174 from ENU-treated transgenic mouse embryonic cell line PX-2. Environ Mol Mutagen 39:55-68
Cosentino, Lidia; Malling, Heinrich V; Heddle, John A (2002) Response of the phiX174 am3, cs70 transgene to acute and chronic ENU exposure: implications for protocol design. Mutat Res 518:113-21
Malling, H V; Delongchamp, R R (2001) Direct separation of in vivo and in vitro am3 revertants in transgenic mice carrying the phiX174 am3, cs70 vector. Environ Mol Mutagen 37:345-55
Delongchamp, R R; Valentine, C R; Malling, H V (2001) Estimation of the average burst size of Phix174 am3, cs70 for use in mutation assays with transgenic mice. Environ Mol Mutagen 37:356-60
Delongchamp, R R; Malling, H V; Chen, J B et al. (1999) An estimator of the mutant frequency in assays using transgenic animals. Mutat Res 440:101-8
Malling, H V (1999) Frederick J. de Serres: the years at the Research Triangle Park (1972-1995). Mutat Res 437:69-75
Malling, H V; Newbold, R R; Lewis, S et al. (1999) Mutagenesis of a single AT basepair in mice transgenic for PhiX174 am3, cs70. II. Brain. Mutat Res 444:85-95