The effect of the gene undulated (un) on the shape of cervical and upper thoracic vertebrae in the house mouse (Mus musculus).

Videodigitised outlines of C6, C7, T1 and T2 vertebrae from 23 mice carrying the mutant gene undulated (un/un) and normal littermates (+/un) have been examined by Fourier analysis. There were large differences in shape between C6 vertebrae, smaller but significant differences in C7 and insignificant differences between T1s. The situation in T2 was complicated by the effects of the genetic background, but the effect of undulated was still significant. We conclude that the undulated gene shows significant pleiotropy in its effects even over this short length of the vertebral column.