Defense Date


Document Type


Degree Name

Doctor of Philosophy


Microbiology & Immunology

First Advisor

P. H. Coleman


Studies were conducted in DUB/ICR mice with minute virus of mice (MVM), a single stranded DNA virus, and Colorado tick fever (CTF) virus, a double stranded RNA Virus, to determine if CTF virus had teratogenic potential and to characterize further MVM and its teratogenic effects. MVM is a known teratogen, whereas CTF virus had never been investigated previously for teratogenic potential.

In characterization studies of MVM infectivity, the following were determined: (a) Rat embryo cells proved to be superior to six cell lines in assaying for MVM infectivity; (b) MVM infectivity could be inactivated with common laboratory disinfectants, ultraviolet radiation, temperatures 45 C to 100 C, and acid treatment: although in some cases a resistant population of MVM was detected; (0) MVM was relatively stable at 4 C and was very stable when stored in liquid nitrogen; (d) In the infected mouse, MVM was found to be firmly associated with the erythrocyte fraction of the blood; (e) MVM was a poor inducer of interferon, but was sensitive to the action of interferon.

In teratogenic studies with MVM infection in mice, incidences of 5% stillbirths and 12 to 25% neonatal deaths were noted. In addition, between 77% to 91% of fetuses, and up to 51% of surviving neonates (to four weeks of age) had detectable MVM. Growth rates, weight gains, and developmental characteristics were normal for mice delivered of mothers inoculated with MVM.

Teratogenic studies with Colorado tick fever (CTF) virus infection in mice revealed a high incidence of stillbirths (6 to 45%) and neonatal deaths (26 to 50%). CTF was demonstrated to cross the placenta and to replicate in the placenta and fetus and could be isolated from stillborns, newborns, and dead neonates. Several developmental aberrations were noted in neonates; however, there was no weight nor growth rate abnormality noted in the survivors. The teratogenic effects of CTF virus were inhibited significantly by neutralization with specific CTF antiserum, proving that the teratogenic effects seen were due to CTF virus.


Scanned, with permission from the author, from the original print version, which resides in University Archives.


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