Selection for Constancy of Score and Pattern of Secondary Vibrissae in Ta/Ta-Ta/Y and Ta/ + Mice

Abstract

In wild-type mice, total secondary vibrissa score is almost invariably 19. This score is made up of the scores at three paired sites and one median site on the head and one paired site on the fore paws, namely supraorbital (2/2), postorbital (1/1), postoral (2/2), inter-ramal (3) and ulnacarpal (3/3). When the sex-linked gene Tabby (Ta) is introduced, total score is reduced in all genotypes and total and individual site scores become more variable. In Ta/Ta females and Ta/Y males total score becomes about seven as a result of score reductions at all sites. The most common scores at these sites are: supraorbital (1/1), postorbital (0/0), postoral (1/1), inter-ramal (1), and ulnacarpal (1/1). In Ta/ + females total score becomes about 15, largely as a result of score reductions at the sites around the mouth. The most common scores at these sites are postoral (1/1) and inter-ramal (1).