International Mammalian Genome Society

The 15th International Mouse Genome Conference (2001)

Table of Contents * Complex Genetics * Developmental Genetics * Gene Annotation * Gene Discovery * Genome Sequencing * Functional Genomics * Mutagenesis * Presentations * Verne Chapman Memorial Lecture

Mr Paul Elms
MRC Harwell
Mammalian Genetics Unit,
Harwell
Didcot OX11 0RD
UK

Co-Authors:  Siggers P, Haines H, Alexander E, Greenfield A, Arkell R 
Institution: Mammalians Genetics Unit, Harwell

Characterisation of the kumba mouse mutant

The Kumba (Ku) mouse mutant was recovered from a genetic screen for dominant, ENU-induced phenotypes.

On some genetic backgrounds, Ku/+ mice exhibit a looped tail, which is occasionally accompanied by spina bifida, making the Kumba mutant a model for neural tube disorders.  Additionally, many Ku/+ mice have a ventral spot and some have a limb defect.  On the C3H background, the mutation shows incomplete penetrance, with one third of heterozygotes appearing normal.  Mice that are homozygous for the mutation die during mid-gestation.

To further investigate the developmental defect associated with this mutation we are characterising the homozygous phenotype at 9.5 dpc.  At this stage, visual analysis of the Ku/Ku embryos reveals delayed neural tube closure, incomplete embryonic turning, incorrect heart looping, a deformed forebrain and a lack of 2nd branchial arch formation.  Analysis with molecular markers has revealed additional defects including aberrant hindbrain segmentation. 

The Ku mutation is linked to distal Chromosome14.  We have shown that the phenotype is caused by a mutation in a zinc finger transcription factor which is expressed throughout the developing nervous system and in the somites, limb buds and eye.