An enhancer-trap LacZ transgene reveals a distinct expression pattern of Kinesin family 26B in mouse embryos.

The enhancer-trap system is a useful tool to uncover genes that exhibit a unique tissue-specific expression. Here, we established a transgenic mouse line in which the reporter gene LacZ was specifically expressed in the developing limbs and face in the embryo. To identify the endogenous genes that are controlled by the limb- and face-specific enhancers, we pinpointed the integration site of the transgene, and analyzed the expression pattern of the genes that were located near the integration site. We found that the gene encoding KIF26B, a member of the kinesin superfamily, was preferentially expressed in the limb buds, face, and somite derivatives. Moreover, while a 7.5-kb mRNA was the major Kif26B transcript in the embryo, it was absent in many adult tissues. These results imply that KIF26B may play a role in embryogenesis, specifically in the development of limbs, face, and somites.