The original RIII strain was known for its high incidence of hormone-dependent mammary tumors transmissible by milk-born MMTV. The RIII/ImrNhsJ substrain is reported to show a pattern of virus expression and tumor incidence similar to the RIII strain (Sarkar, et al. 2004). RIII/ImrNhsJ mice carry the following endogenous MMTV loci: Mtv-6, 8, 14, 17 and possibly 21 (Popken-Harris, et al. 2001). Exogenous MMTV infection leads to the deletion of CD4+ Vbeta-2 and Vbeta-8 peripheral and central T cells (Uz-Zaman, et al. 2003). It is possible to modulate mammary tumor incidence using high and low calorie diets (Li, et al. 1994). RIII/ImrNhsJ mice infected with exogenous MMTV may be useful for studies of human breast cancer activated by insertional mutagenesis.
NOTE: Mice distributed by The Jackson Laboratory are not infected with MMTV. Regrettably, we do not have a source for the virus.
The original RIII line was inbred at the Institut du Radium, Paris by Dobrovolskia-Zavadskaia in 1928 (Hilkens, et al. 1981). This substrain was transferred to Dr. Moore at the Institute of Medical Research (Imr) in Camden, New Jersey in 1950, then to Dr. Nural H. Sarkar (Nhs) at the Medical College of Georgia in 1974. Dr. Sarker donated this strain to The Jackson Laboratory in 2004.
Currently there are no related genes or alleles for this strain.
To maintain viral infectivity and high viral titer, the donating investigator recommends maintaining the strain by sibling matings of the third gestation or higher. Virgin mice fed a standard diet develop tumors at an incidence of 60-70% by 10-12 months, breeding mice develop tumors at an incidence of 90-100% (Li, et al 1994). Virgin mice on a high calorie (16 kcal/day) low fat (5% corn oil) diet have an increased tumor incidence of 73% (Li, et al 1994).
When using the RIII/ImrNhsJ mouse strain in a publication, please include JAX stock #005221 in your Materials and Methods section.