ALLELES: bgl+ (normal), bgl (mutant). Symbol formerly bg.
PHENOTYPE: These deer mice exhibit a pronounced tremor and staggering, awkward gait. The tremor is expressed whenever the animal is awake and at rest. The awkward gait is due to uncoordinated movements of the hind limbs. The trait is most strongly expressed in adults, but there is variable expressivities and low grade 'boggling' behavior is not easily distinguished from the wild-type. The tremor involves the whole body, but head movements are more noticeable. Boggler deer mice are less adept at climbing than normal arivals, but swimming ability is unimpaired. The trait cannot be recognized until after three months of age, and expression occasionally is delayed until the animal is more than a year old.
SOURCE: About 1948. University of Michigan. The trait appeared within a stock of P.m. blandus descended from deer mice trapped near Tularosa, New Mexico. Apparently the first laboratory generation carried the mutant gene.
REFERENCE: Barto (1955), Vandermeer and Barto (1969).