Selection for an Invariant·Character, Vibrissa Number, in the House Mouse

Abstract

The number of secondary vibrissae in the mouse is normally 19. The tabby gene reduces this to about half and causes a marked variability of vibrissa number. Selection on tabby mice for increase and decrease in vibrissa number has been successful. These selection lines were maintained in segregation for + and Ta alleles, and this selection, practised solely on tabby mice, has resulted in both an increase and decrease in vibrissa number in normal mice.