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Analysis of mice with a P3 deletion in the DCC gene
Neuronal circuits are essential components of the nervous system. They provide the necessary processing power so the brain can react to external stimuli as well as controlling the body. In some cases, neuronal circuits have been reasonably well characterised, predominantly in simpler animals partly because these neuronal circits are smaller and easier to study. Walking or locomotion is believed to be initiated and modulated by signals from higher centres in the brain like the motorcortex and the cerebellum. Once initiated, the rhythmic activity of walking is selfsustained and for these repetitive nerve impulses that support walking, the brain is not needed (one classical example of this phenomenon is a chicken running without a head). Circuits of neurons referred to as the central pattern generator (CPG) maintain this self-sustainable activity in the spinal cord. For proper walking and locomotion, the CPGs on each side of the midline of the spinal cord need to communicate in order to activate of one side of the body while preventing activation of the other side of the body.
The mammalian axon guidance molecules Netrin, DCC (deleted in colorectal cancer) and RCM were all found in the C. elegans screen for uncoordinated (unc) mutants (unc-6, unc-40 and unc-5, respectively). We now want to analyse the involvement of Netrin and DCC in setting up the CPG. Targeted deletion in the mouse of either Netrin or DCC lead to perinatal lethality, which complicates analysis of locomotory activity. A spontaneous mutation in exon 28 of the DCC gene have generated a hypomorphic allele of DCC. Such mice survive until three weeks of age and display a parallell gait with their hindlimbs, similar to what has earlier been reported in EphA4 and EphrinB3 null mutant mice. In contrast to neurons that express EphA4, neurons that express DCC are destined to cross the midline. We therefore anticipate that DCC may be a marker for a group of neurons not previously identified, which are critical for CPG development and coordination. In this project, you are expected to use tracing techniques to analyse the defects in spinal cords from these mice. In addition, by usage of known markers and possibly some novel markers from project 1, you will determine what neuronal population are affected in these mice.
Methods: Microdissection, genotyping, in-situ hybridisation, tracing
Your preferred background is in biomedicine or molecular biology. Previous experience with neurobiology or molecular biology is a plus.
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