THE STUMBLER MUTATION MAPS TO PROXIMAL MOUSE CHROMOSOME-2

The cerebellar mouse mutation stumbler (stu) was mapped to proximal Ch romosome (Chr) 2 with a recently developed polymerase chain reaction a ssay for endogenous retroviruses that vary between mouse strains. The stu locus resides between the markers D2Mit5 and D2Mit7. A number of d evelopmentalIy or neurologically relevant candidate genes map in this region, including Bmi1, Dbh, Grin1, Notch1, Pax8, Rxra, and Spna2. Kno wing the chromosomal localization of stu should simplify maintenance o f the stumbler mouse stock and also enable analysis of the cerebellar defect in presymptomatic individuals.