Abstract
The BALB/c mouse strain has been shown to contain endogenous mouse mammary tumor virus (MMTV) proviral sequences. However, no exogenous MMTV particles have been detected in their tissues. Female BALB/c mice from our colonies exhibit a very low incidence of spontaneous mammary tumors (SMT); less than 1% at up to 20 mo of age. Immunodeficient BALB/c mice heterozygous for the nude gene (nu/+, +/+), for the dominant hemimelia gene associated with asplenia (+/+, Dh/+), or for both traits (nu/+, Dh/+) have been examined for SMT incidence and the presence of MMTV proviruses. Based on restriction digestion with Eco RI, Bam HI, and Pst I, the immunodeficient mice have an MMTV provirus copy number and organization identical to the BALB/cCrgl strain. This MMTV DNA pattern is distinct from the MMTV proviruses in C3H/He, C57BL/6J and CBA/CaJ mice, which were parental strains of the immunodeficient mutants. Normal female BALB/c or BALB/c heterozygous for the asplenic trait do not develop significant numbers of SMT at up to 19 mo of age. In contrast, an incidence of 23.8% and 57.7% SMT was observed in BALB/c nu/+ heterozygotes, and in BALB/c nu/+, Dh/+ heterozygotes, respectively. These results indicate that agenesis of the spleen, concomitant with the presence of the heterozygous nude gene, contribute to a high incidence of SMT in the low-SMT BALB/c mouse strain.
Full Text
The Full Text of this article is available as a PDF (663.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Cohen J. C., Majors J. E., Varmus H. E. Organization of mouse mammary tumor virus-specific DNA endogenous to BALB/c mice. J Virol. 1979 Nov;32(2):483–496. doi: 10.1128/jvi.32.2.483-496.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Flanagan S. P. 'Nude', a new hairless gene with pleiotropic effects in the mouse. Genet Res. 1966 Dec;8(3):295–309. doi: 10.1017/s0016672300010168. [DOI] [PubMed] [Google Scholar]
- Groner B., Buetti E., Diggelmann H., Hynes N. E. Characterization of endogenous and exogenous mouse mammary tumor virus proviral DNA with site-specific molecular clones. J Virol. 1980 Dec;36(3):734–745. doi: 10.1128/jvi.36.3.734-745.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lozzio B. B. Hematopoiesis in congenitally asplenic mice. Am J Physiol. 1972 Feb;222(2):290–295. doi: 10.1152/ajplegacy.1972.222.2.290. [DOI] [PubMed] [Google Scholar]
- Michalides R., van Nie R., Nusse R., Hynes N. E., Groner B. Mammary tumor induction loci in GR and DBAf mice contain one provirus of the mouse mammary tumor virus. Cell. 1981 Jan;23(1):165–173. doi: 10.1016/0092-8674(81)90281-6. [DOI] [PubMed] [Google Scholar]
- Pantelouris E. M. Absence of thymus in a mouse mutant. Nature. 1968 Jan 27;217(5126):370–371. doi: 10.1038/217370a0. [DOI] [PubMed] [Google Scholar]
- Pauley R. J., Medina D., Socher S. H. Murine mammary tumor virus expression during mammary tumorigenesis in BALB/c mice. J Virol. 1979 Feb;29(2):483–493. doi: 10.1128/jvi.29.2.483-493.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pauley R. J., Parks W. P., Popko B. J. Expression and demethylation of germinally-transmitted BALB/c mouse mammary tumor virus DNA in Abelson MuLV B-lymphoid cell lines. Virus Res. 1984;1(5):381–400. doi: 10.1016/0168-1702(84)90025-x. [DOI] [PubMed] [Google Scholar]
- SEARLE A. G. Hereditary absence of spleen in the mouse. Nature. 1959 Oct 31;184(Suppl 18):1419–1420. doi: 10.1038/1841419b0. [DOI] [PubMed] [Google Scholar]
- van Nie R., Verstraeten A. A. Studies of genetic transmission of mammary tumour virus by C3Hf mice. Int J Cancer. 1975 Dec 15;16(6):922–931. doi: 10.1002/ijc.2910160606. [DOI] [PubMed] [Google Scholar]