This thyroid peroxidase mutant is useful for studies related to thyroid hormone and thyroid function. Homozygotes have dysplastic thyroid glands, severe proportional dwarfing, and delayed cochlear development with severe hearing deficit due to a lack of thyroid hormone production.Read More +
Mice homozygous for the teeny 2 Jackson mutation are proportional dwarfs, distinctly smaller than their heterozygous siblings. This is evident by one week of age. These mutants are severely hypothyroid with undetectable levels of T4 at 5 to 8 weeks of age. The thyroid glands are dysplastic with poorly developed follicles and hyperproliferation of epithelial cells. Although no defects have been found in the eyes, these mutants have highly elevated ABR thresholds at 4 weeks of age, the earliest age assessed, indicative of severe hearing impairment. The cochlear development is delayed and, although the cochlea resembles a normal cochlea by 1 month of age, the tectorial membrane remains abnormally thickened. Homozygotes fail to breed.
The teeny 2 Jackson mutation arose spontaneously at The Jackson Laboratory in a congenic strain in which H2g7 had been backcrossed onto the C57BL/6J host background. This mutant subline was maintained by sibling intercrossing, homozygous for H2g7 and segregating for teeny 2 Jackson, for several years and then by backcrossing to C57BL/6J, breeding out the H2g7. This strain reached generation N6 in 2014.
|Allele Name||teeny 2 Jackson|
|Gene Symbol and Name||Tpo, thyroid peroxidase|
|Strain of Origin||B6.NOD-H2g7|
|Molecular Note||This spontaneous 64 base pair deletion includes the last 35 base pairs of exon 5 and the first 29 base pairs of intron 5, which includes the 5 prime splice donor site, and yields no normal transcript and two abnormal transcripts: a 740 bp transcript skipping only exon 5, which is predicted to causes a frame shift resulting in 12 incorrect amino acid substitutions beginning at residue 111 then a premature stop codon; and a 588 bp transcript skipping exons 4 and 5, which is predicted to delete 95 amino acids, residues 61-155.|
Because homozygotes do not breed this strain is maintained by sibling intercrossing heterozygotes.
When using the B6(Cg)-Tpotee-2J/GrsrJ mouse strain in a publication, please cite the originating article(s) and include JAX stock #026224 in your Materials and Methods section.