Mice that are homozygous for this Hint1 (histidine triad nucleotide binding protein 1) targeted mutation are more sensitive to chemical carcinogens, have an increased spontaneous tumor incidence, decreased spontaneous (basal) locomotor activity and enhanced response to amphetamine. MEFs isolated from homozygotes exhibit more rapid growth, spontaneous immortalization, are more resistant to ionizing radiation, and impaired DNA repair. This mutant mouse strain may be useful in studies of DNA repair and chromatin remodeling, tumorigenesis, amphetamine-evoked hyperactivity and behavior and dopamine neurotransmission.
Haiyang Li, Columbia University
Mice that are homozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. No gene product (protein) is detected by Western blot analysis of MEFs, cerebrum, cerebellum, colon, kidney, thymus, thyroid, stomach,
liver, pancreas, adrenal gland, testis, ovary, heart, lung, spleen, muscle, and skin tissues. No gene product (mRNA) is detected by RT-PCR of MEFs. Homozygotes have smaller thymuses. Homozygotes MEFs exhibit more rapid growth after 8 serial passages, and undergo spontaneous immortalization, as they can be cultured for more than 50 serial passages without morphological changes. Both early and late passage homozygotes MEFs are more resistant to ionizing radiation than wildtype controls. Irradiated MEFs have impaired DNA repair and exhibit chromosome aberrations, and genomic instability. Homozygotes are more sensitive to chemical carcinogens NMBA and DMBA and develop more tumors that are larger and more malignant. Mutant mice that are 2 to 3 years of age have an increased spontaneous tumor incidence. Heterozygotes also display increased susceptibility to DMBA induced tumors. Homozygotes have decreased spontaneous (basal) locomotor activity and enhanced response to amphetamine. This mutant mouse strain may be useful in studies of DNA repair and chromatin remodeling, tumorigenesis, amphetamine-evoked hyperactivity and behavior and dopamine neurotransmission.
A targeting vector containing PGKneo was used to disrupt 1.6kb of sequence containing the first exon, upstream sequence and part of the downstream intron. The construct was electroporated into 129 derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric animals were crossed to C57BL/6 mice, and then backcrossed to 129 for 8 generations (see SNP results below). Upon arrival at The Jackson Laboratory, the mice were crossed to 129S1/SvImJ (Stock No. 002448) for one generation to establish the colony.
A 27 SNP (single nucleotide polymorphism) panel analysis performed by The Jackson Laboratory revealed 9 of 27 markers (on nine different chromosomes) that were not 129 allele-type. These data suggest C57BL/6 genetic contamination prior to arrival at The Jackson Laboratory.
|Allele Name||targeted mutation 1, I Bernard Weinstein|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Hint1, histidine triad nucleotide binding protein 1|
|Strain of Origin||129|
|Molecular Note||A 1.6 kb genomic fragment was replaced with a neomycin selection cassette inserted via homologous recombination. Normal protein was undetected by Western blot analysis of various organs obtained from homozygous mutant mice.|
|Mutations Made By|| |
Haiyang Li, Columbia University
When maintaining a live colony, these mice can be bred as homozygotes.
When using the 129;B6-Hint1tm1Ibw/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #009443 in your Materials and Methods section.