of Mice: A2G
Inbr: F 101. Albino. Genet: b,
c. Originated as an illegitimate
mating of strain A at Glaxo Laboratories, UK, in 1942-50, followed by
b x s mating. Should not be considered as a substrain of A. Distributed
mainly in European laboratories, and best known for its unique resistance
to myxovirus (influenza) infections.
Whisker chewing 75% in cages of 2-3 mice by 60 days of age. Whisker trimming
seems to be associated with social dominance (Strozik
and Festing 1981
). Low balsa-wood gnawing activity (3/16) in A2G-hrhr
but high activity in A2G (1/16) (Fawdington and Festing 1980). It is not
prevented by offering the mice means of withdrawal from it (Van den Broek et al, 1993
Life-span and spontaneous disease
Long life-span in males (13/17 = 640 days) but intermediate in females
(8/17 = 644 days), and lung tumours 17-65% in SPF fostered conditions
(Festing and Blackmore, 1971
Normal physiology and biochemistry
High incidence of audiogenic seizures (Pasquini et al, quoted by Al-Ani et al., 1970
Absence of third molar in 7% of cases (1/20) (Festing, 1975b). High incidence
of absence of the 3rd. molar, which has been used as a threshold character
to study the effects of weak teratogens (Berry
and Nickols 1979
Sensitive to insulin (2/9) but insensitive to histamine (7/9) (Brown,
). Long survival on Warfarin (9/12) (Lush
and Arnold, 1975
). Long sleeping time under hexobarbital anaesthetic
(13/15) (Lovell, 1976), long sleeping time under pentobarbitone anaesthetic
(18/23), Lovell (1986
). Highly susceptible
to lung tumour induction by urethane (cf. strain A) (Festing
Incidence of serum antinuclear factor high (2/17) at 28% (Barnes and Tuffrey, 1967
). Low antibody affinity to HSA
(7/9) (Petty et al., 1972
Uniquely resistant among twenty strains tested to infection with diverse
strains of pneumotropic and neurotropic influenza viruses. Resistance
is due to a dominant autosomal gene, (now designated Mx1) and does not
depend on the immune system (Fiske and Klein,
1975; Lindenman et al., 1963
1963). The Mx1 protein exhibits GTPase activity (Nakayama et al, 1993
). The Mx1 protein is inducible with interferon
and has been used as a cellular marker in studying the movement of glial
cells toward a spinal cord demyelinating lesion (Gout
and Dubois-Dalcq, 1993
). Mx1 exerts its antiviral activity by interfering
with the function of the influenza virus polymerase subunit PB2 (Stranden et al, 1993
). The Mx1 gene also confers resistance
to the tick-born Thogoto virus (Haller et
) and the tick-born Dhori virus (Thimme
et al, 1995
Develops a chronic non-healing lesion on infection with Leishmania
tropica, the parasite causing cutaneous leishmaniasis (Howard et al 1980)
Good breeding performance (7/25), colony output 1.2 young per female per
week, litter size at weaning 5.7 (12/25) (Festing, 1976a).
A. T., Tunnicliff G., Rick J. T., and Kerkut G. A. (1970) GABA production,
acetylcholinesterase activity and biogenic amine levels in brain for mouse
strains differing in spontaneous activity and reactivity. Life Sci.
R. D. and Tuffrey M. (1967) Serum antinuclear factor and the influence
of environment in mice. Nature 214, 1136-1138.
L. and Nickols C. D. (1979) The effects of aspirin on the development
of the mouse 3rd. molar. Arch. Toxicol. 42, 185-190.
Brown A. M. (1965) Pharmacogenetics
of the mouse. Lab. Anim. Care 15, 111-118.
M. F. W. and Blackmore D. K. (1971) Life span of specified-pathogen-free
(MRC category 4) mice and rats. Lab. Anim. 5, 179-192.
Festing M. F. W.
(1980) Inbred strains and the factorial experimental design in toxicological
screening, in Animal Quality and Models in Biomedical Research. Proceeding
of the 7th. ICLAS Symposium, Utrecht (Spiegel A., Erichsen S., and
Solleveld H. A., eds), pp. 59-66. Gustav Fischer, Stuttgart.
D. and Klein P. A. (1975) Effect of immunosuppression on the genetic resistance
of A2G mice to neurovirulent influenza virus. Infect. Immun.
Gout O. and
Dubois-Dalcq M. (1993) Directed migration of transplanted glial cells
toward a spinal cord demyelinating lesion. International Journal of
Developmental Neuroscience 11, 613-623.
O., Frese M., Rost D., Nuttall P. A., and Kochs G. (1995) Tick-borne Thogoto
virus infection in mice is inhibited by the orthomyxovirus resistance
gene product Mx1. Journal of Virology 69, 2596-2601.
J. G., Hale C., and Chan-Liew W. L. (1980) Immunological regulation of
experimental cutaneous leishmaniasis 1. Immunogenetic aspects of susceptibility
to Leishmania tropica in mice. Parasite Immunol. 2, 303-314.
J., Lane C. A., and Hobson D. (1963) The resistance of A2G mice to myxoviruses.
J. Immunol. 90, 942-951.
Lovell D.P. (1986)
Variation in pentobarbitone sleeping time in mice. I. strain and sex differences.
Lab. Anim. 20, 85-90.
Lush I. E.
and Arnold C. J. (1975) High coumarin 7-hydroxylase activity does not
protect mice against Warfarin. Heredity 35, 279-281.
M., Yazaki K., Kusano A., Nagata K., Hanai N., and Ishihama A. (1993)
Structure of mouse Mx1 protein. Molecular assembly and GTP-dependent conformational
change. J. Biol. Chem. 268, 15033-15038.
E., Steward M. W., and Soothill J. F. (1972) The heterogeneity of antibody
affinity in inbred mice and its possible immunopathologic significance.
Clin. Exp. Immunol. 12, 231-241.
A. M., Staeheli P., and Pavlovic J. (1993) Function of the mouse Mx1 protein
is inhibited by overexpression of the PB2 protein of influenza virus.
Virology 197, 642-651.
E. and Festing M. F. W. (1981) Whisker trimming in mice. Lab. Anim.
R., Frese M., Kochs G., and Haller O. (1995) Mx1 but not MxA confers resistance
against tick-borne Dhori virus in mice. Virology 211,
Van den Broek
F. A. R., Omitzigt C. M., and Beynen A. C. (1993) Whisker trimming behaviour
in A2G mice is not prevented by offering means of withdrawal from it.
Lab. Anim. 27, 270-272.
INBRED STRAINS OF MICE
Updated 9 Apr. 1998
MRC Toxicology Unit, Hodgkin Building,
University of Leicester,