Mice homozygous mice for the dwarf Jackson spontaneous mutation (Pou1f1dw-J) have a phenotype very similar to mice homozygous for the original dwarf mutation (Pou1f1dw). Homozygous mutant mice are characterized by severe proportional dwarfing, sterility, and hypothyroidism. Adult dwarf mice are about one-fourth to one-third the size of wildtype mice. There is a lack of growth hormone, prolactin and thyroid stimulating hormone producing cells in the anterior pituitary leading to severe endocrine deficiency of these hormones. Homozygous mutant mice show a transient loss in cortical thymocytes associated with the primary defect in anterior pituitary.
The dwarf Jackson mutation (Pou1f1dw) arose spontaneously in strain C3H/HeJ at generation F136 in 1973 at The Jackson Laboratory. It was maintained by mating heterozygous tested sibling pairs until generation F15. It was then maintained by ovarian transplant using the cross-intercross system to generation N6 and then again by tested heterozygous pair matings. It was cryopreserved in 1983 by mating heterozygous (Pou1f1dw-J/J) males at generation F136+16N6F1 to C3H/HeJ females.
|Allele Name||dwarf Jackson|
|Allele Synonym(s)||dwarf-J; dwJ; Pit1dwJ|
|Gene Symbol and Name||Pou1f1, POU domain, class 1, transcription factor 1|
|Strain of Origin||C3H/HeJ|
|General Note||This remutation of the Snell dwarf gene occurred in the C3H/HeJ strain (J:6342). Mutant mice homozygous for Pit1dw-J, like homozygotes for Pit1dw, lack PIT1 protein activity and have no lactotrophs, thyrotrophs, or somatotrophs (J:10774).|
|Molecular Note||The mutation was characterized by Southern blot as either a chromosomal inversion or an insertion of greater than 4kb in the gene. PCR analysis revealed that most of exon 3 is intact, but the exact break points are not established.|