Expression of kinesin superfamily genes in cultured hippocampal neurons.

The nature of the different kinesin family members that function in a single, specific neuron type has not been systematically investigated. Here, we used quantitative real-time PCR to analyze the developmental expression patterns of kinesin family genes in cultured mouse hippocampal neurons, a highly homogeneous population of nerve cells. For purposes of comparison, we also determined the set of kinesins expressed in embryonic and adult hippocampal tissue. Twenty kinesins are expressed at moderate-to-high levels in mature hippocampal cultures. These include 9 plus-end directed kinesins from the Kinesin-1, -2, and -3 families that are known to mediate organelle transport and 6 other members of the Kinesin-3 and -4 families that are candidate organelle motors. Hippocampal cultures express high levels of a Kinesin-13, which regulates microtubule depolymerization, and moderate-to-high levels of Kinesin-9 and -14 family members, whose functions are not understood. Twelve additional kinesins, including 10 known mitotic kinesins, are expressed at moderate levels in embryonic hippocampus but at very low levels in mature cultures and the adult hippocampus. Collectively, our findings suggest that kinesins subserve diverse functions within a single type of neuron.