Data from: Genetic mapping of molar size relations identifies inhibitory locus for third molars in mice

Molar size in Mammals shows considerable disparity and exhibits variation
similar to that predicted by the Inhibitory Cascade model. The importance
of such developmental systems in favoring evolutionary trajectories is
also underlined by the fact that this model can predict macroevolutionary
patterns. Using backcross mice, we mapped QTL for molar sizes controlling
for their sequential development. Genetic controls for upper and lower
molars appear somewhat similar, and regions containing genes implied in
dental defects drive this variation. We mapped three relationship QTLs
(rQTL) modifying the control of the mesial molars on the focal third
molar. These regions overlap Shh, Sostdc1 and Fst genes, which have
pervasive roles in development and should be buffered against new
variation. It has theoretically been shown that rQTL produces new
variation channeled in the direction of adaptive changes. Our results
provide evidence that evolutionary/disease patterns of tooth size
variation could result from such a non-random generating process.