Minute virus of mice (MVM) nucleic acid production in susceptible and resistant strains of mice and F 1 hybrids

Abstract

Susceptibility of neonatal mice to the lethal effects of the virulent allotropic variant of minute virus of mice is controlled by host genotype. We quantitated MVM-DNA production in resistant C57BL 6 (B6), susceptide C3H He (H), and (B6 × H) F 1 (F 1) hybrid mice. Total DNA extracted from six organs of infected mice on post inoculation days (PID) 3, 5, 7, and 9 was analyzed by dot blot and Southern blot assays. 7 to 100-fold more viral DNA was produced in H mice than in B6 mice on PID 7 depending on the organ and F 1 mice phenotypically resembled B6 mice. Southern blot analysis of DNA extracted from infected mice on PID 7 showed a prominent single-stranded band (5 kb, virion DNA) and a faint replicative form (5 kb, double-stranded) in all strains of mice. Total RNA extracted from the organs of B6, H, and F 1 mice was analyzed by Northern blot. Viral mRNA production was generally below detection limits. In kidneys, hearts, and intestines of some H mice on PID 7, however, a 1.9 kb transcript was detected, smaller than transcripts for R1, R2 or R3. This study confirms that susceptibility to lethal MVMi infection correlates with upregulation of MVM DNA production, a recessive trait, and perhaps with the production of a novel 1.9 kb transcript.