MA/MyJ

Stock number: 000677
Product name: Marsh Albino Murray
Research areas: Metabolism Research, Neurobiology Research, Research Tools, Sensorineural Research

Description

A characteristic of MA/MyJ is the spontaneous mutation hf (hepatic fusion), which results in varying degrees of fusion in the hepatic lobes. Mice of this strain are generally resistant to X-irradiation. They have a low spontaneous mammary tumor incidence, but are highly susceptible to the mammary tumor virus.

Detailed description

A characteristic of MA/MyJ is the spontaneous mutation hf (hepatic fusion), which results in varying degrees of fusion in the hepatic lobes.

This strain is a poor breeder.

Development

Originally M.C. Marsh's strain 3, which was started from a pair of mice from the Lathrop-Loeb colony (1903-1915). Cousin matings were carried out by Marsh before being inbred by W. S. Murray.

Allele

Symbol: hf
Name: hepatic fusion
MGI accession ID: MGI:1856607
Generation method: Spontaneous
Marker symbol: hf
Marker name: hepatic fusion
Chromosome: 7
Strain of origin: MA/MyJ
Molecular note: This phenotypic mutant was identified at The Jackson Laboratory.

Allele

Symbol: Cdh23^ahl
Name: age related hearing loss 1
MGI accession ID: MGI:3028349
Generation method: Spontaneous
Marker symbol: Cdh23
Marker name: cadherin 23 (otocadherin)
Chromosome: 10
Strain of origin: multiple strains
Molecular note: Genetic complementation tests have shown allelism between the mdfw (modifier of deaf waddler) locus and the ahl locus. Further analysis has shown this is caused by a G to A transition at coding nucleotide position 753 of Cdh23 (SNP rs257098870). This hypomorphic allele changes splice donor site G-GT to A-GT, causing frame skipping of exon 7. This is predicted to delete part of the 2nd and 3rd ectodomains and cause reduced message stability. Twenty-seven strains classified with ahl and carrying the 753A allele include: CD-1, RBF/DnJ, PL/J, AKR/J, RF/J, BALB/cBy, A/WySnJ, P/J, SENCARA/PtJ, DBA/1J, ALS/LtJ, C58/J, C57BLKS/J, 129P1/ReJ, C57BR/cd, SKH2/J, BUB/Bn, MA/MyJ, LP/J, 129X1/SvJ, NOR/LtJ, A/J, C57BL/6, NOD/LtJ, DBA/2J, ALR/LtJ, C57L/J. Strains classified with ahl that DO NOT carry this mutation include: 129S1/SvImJ, C3H/HeSnJ, I/LnJ, YBR/Ei, MRL/MpJ.

Allele

Symbol: Ahr^b-1
Name: b-1 variant
MGI accession ID: MGI:2667308
Generation method: Not Applicable
Marker symbol: Ahr
Marker name: aryl-hydrocarbon receptor
Chromosome: 12
Strain of origin: C57BL/6J
Molecular note: This allele encodes a high affinity, relatively heat stabile, 95 kDa receptor. PCR sequencing of cDNA revealed ten nucleotide differences between the coding sequences of the DBA/2J and C57BL/6J receptors. Five of the ten differences would cause amino acid changes. One of these, a C to T transition in exon 11 would change the arginine codon in the DBA/2J allele to an opal termination codon in the C57BL/6J allele. This change would prevent the 43 amino acid extension of mRNA translation predicted for the DBA/2J allele and account for the smaller size of the peptide produced by this allele (95 kDa vs 104 kDa for the DBA/2J allele). A second C to T transition changes a proline codon in the DBA/2J allele to leucine codon in the C57BL/6J allele, and would likely change secondary structure of the peptide and thus ligand affinity.
General note: C57BL/6 carries the responsive Ahr^b allele; DBA/2 carries nonresponsive Ahr^d. Heterozygotes (Ahr^b/Ahr^d) are responsive (J:5282). Later work identified a second (J:8895) and later a third (J:22144) allele conferring response. Thus the allele in C57, C58, and MA/My strains is now Ahr^b-1; Ahr^b-2 is carried by BALB/cBy, A, and C3H; and Ahr^b-3 by Mus spretus, M. caroli, and MOLF/Ei. The nonresponsive strains AKR, DBA/2, and 129 carry Ahrd (J:22144). Nucleotide and amino acid sequence differences between Ahr^b-1 and Ahr^d have been determined (J:17460).

Strain of origin - this allele was found in C57BL/6, C58/J, C57BR, MA/My strains

Allele

Symbol: Mx1^s1
Name: myxovirus susceptibility 1
MGI accession ID: MGI:3715154
Generation method: Spontaneous
Attributes: Null/Knockout
Marker symbol: Mx1
Marker name: MX dynamin-like GTPase 1
Chromosome: 16
Strain of origin: multiple strains
Molecular note: Many inbred mouse strains have an exon 9 to 11 deletion, resulting in a null allele and susceptibility to myxoviruses, including: A/J, ABP/Le, AKR/J, AU/SsJ, BALB/cJ, BDP/J, BUB/BnJ, C3H/HeJ, C57BL/6J, C57BL/10J, C57BL/KsJ, C57L/J, C58/J, DA/HuSn, DBA/2J, FSB/GnEi, FVB/NJ, LIS/A, LP/J, MA/MyJ, MAS/A, NZB/BINJ, P/J, PL/J, RIIIS/J, RF/J, SEA/GnJ, SEC1/ReJ, SJL/J, ST/bJ, TS1/A, TW1/A. YBR/Ei, 020/A, 129/J, SF/CamEi and SK/CamEi.
General note:

The Mx genes determine resistance to the lethal effects of various myxoviruses including neurotropic avian influenza A virus injected intracerebrally, pneumotropic strains injected intranasally, and a hepatotropic strain injected intraperitoneally (J:5645, J:13136). Resistance is not dependent on presence of the thymus and is not abolished by immunosuppression or by inhibitors of macrophage function (J:5735, J:5478, J:5645). Resistance is specific for the orthomyxoviruses (J:6265). It is dependent on the presence of interferon-alpha and -beta but not -gamma (J:7365).

The resistance allele at the Mx1 locus, under induction by alpha/beta interferon, produces the 75 kDa protein MX-1, which confers resistance to the influenza virus, in the nuclei of cells carrying the allele. Susceptibility alleles do not produce the protein (J:8273). The protein is located in the nucleus (J:7703) and produces its antiviral effect by preventing synthesis of viral mRNA in the nucleus (J:7992). Nuclear localization is necessary for anti-influenza virus activity (J:1417), but mutations induced in Mx1 showed that nuclear position was not sufficient for the effect; mutations in several domains can cause its loss (J:11840). The MX-1 protein is a GTPase containing a GTP binding domain (J:1417) and this binding core is also necessary (J:21243).

Resistance is expressed by macrophages and other cells in vitro (J:6649, J:5940) but could not be transferred to susceptible animals by transfer of macrophages from resistant mice (J:6149).

Resistance to infection with two tick-borne viruses, Thogoto virus (J:8273) and Dhori virus (J:27760), is also conferred by Mx1^r.

The Mx1^r allele occurs only in strains A2G, SL/NiA, and T9, the latter being a strain derived from an influenza-resistant wild stock, and CAST/Ei, derived from Mus musculus castaneus. Most inbred strains, including C57BL/6J, C3H/HeJ, and BALB/cJ, carry an influenza susceptible Mx1^s1 allele which produces mRNA lacking exons 9, 10, and 11 of the Mx1^r allele. This large deletion apparently renders the protein incapable of providing resistance to influenza. The CBA/J, CE/J, I/LnJ, and PERA/Ei strains, also susceptible to the virus, have another form of the Mx1^s2 allele in which there is a nonsense mutation (J:9452).

Interferon is induced by viral infection and in turn induces the Mx protein (J:7703). Although some interferon-induced genes respond directly to virus invasion as well as indirectly through induction by virus-induced interferon, this primary response is very weak for the MX-1 protein in response to either influenza or Newcastle disease viruses (J:1892).

Allele

Symbol: B2m^a
Name: a variant
MGI accession ID: MGI:6357680
Generation method: Spontaneous
Attributes: Not Applicable
Marker symbol: B2m
Marker name: beta-2 microglobulin
Chromosome: 2
Strain of origin: multiple strains
Molecular note: The a variant is slightly slower running on SDS PAGE and was found to have an aspartic acid at amino acid position 85. This allele is found in A, BALB/c, LP and most other strains.