The inheritance of vertebral shape in the mouse. II. A study using Fourier analysis to examine the inheritance of patterns of vertebral variation in the cervical and upper thoracic vertebral column.

In this paper we continue an earlier study which examined shape differences between the cervical and upper thoracic vertebrae of 2 inbred strains of mice (CBA, C57BL) and their F1. Our earlier study showed that the amount of shape difference varied between different vertebrae, even from adjacent levels, and that the vertebrae of the F1s showed a degree of resemblance to one or other parental strain which varied from vertebral level to vertebral level. We have suggested that this variation from level to level may have evolutionary significance in that it demonstrates a degree of autonomy in the genetic control of vertebral morphology between successive levels and, as such, allows the possibility of a form of mosaic evolution. In this study we further consider the inheritance of vertebral morphology both in the above-mentioned and in other crosses: this time, however, we focus on the ways in which vertebral morphology changes from level to level and on any differences in patterns of metameric change between inbred strains and their offspring. Our findings indicate that the morphology of vertebrae shows a metameric gradation in shape and that the rates of shape change along the column can vary from region to region. Furthermore, the F1 between 2 inbred strains may follow the pattern of variation characteristic of one parent for several metameric segments at a time. Different crosses between different inbred strains indicate that many genes influence the pattern of metameric variation in the vertebral column and that these genes have different actions along the column.(ABSTRACT TRUNCATED AT 250 WORDS)