Insertional mutation of the hairless locus on mouse Chromosome 14

Crosses between heterozygous transgenic mice from line 5053 produced offspring with progressive irreversible hair loss beginning at day 10. With increasing age, the skin of these animals became thicker and plicated in appearance. Histological analysis revealed the complete absence of normal hair follicles and numerous intradermic cystic structures, which enlarged with time and became filled with keratinaceous material. Test crosses demonstrated that the affected animals are homozygous for the transgene insertion. The clinicla and histological phenotype of the new mutant closely resembles that of the rhino allele at the hairless locus on Chromosome (Chr) 14. Complementation tests and linkage analysis indicate that the transgene has interrupted the hairless locus. It has been demonstrated previously that mutation at the hr locus is accompanied by a variety of immune deficiencies. Many of the older affected transgenic mice developed an impetigo-like skin eruption which responded to antibiotic ointment and which may reflect impaired immune function. The transgenic allele, hr TgN5053Mm , will be useful for identification of the transcription unit of the hairless locus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47000/1/335_2004_Article_BF00360900.pd

Mitotic Chromosome Preparations from Mouse Cells for Karyotyping

This unit contains protocols for the preparation of mitotic chromosomes from mouse peripheral blood, Giemsa banding of those chromosomes, and classification into a karyotype, including recognition of some common pitfalls of misidentification and information for determining aberrant chromosomes. The methods described can be used to identify visible chromosomal rearrangements and their precise cytological breakpoints in the living mouse. In conjunction with fluorescent in situ hybridization (FISH), the metaphase spreads can also be used for the linear placement of loci on a chromosome and for determining the insertion site(s) of a foreign transgene