| Description | The oculomotor nerve has a significant role in innervating the extraocular muscles of the
eye that are necessary for the proper positioning and movement of the eye. Defects in the
development of the oculomotor system can result in strabismus, a misalignment of the
eyes, which left uncorrected can lead to partial blindness. Surprisingly, little is known
about the embryonic development of the oculomotor nerve. Oculomotor neurons (OMNs)
innervating the dorsal rectus undergo a unique migration through the midline to achieve a
contralateral innervation pattern. Slit/Robo signaling has been shown to have an
important role in the guidance of midline crossing axons, but less is known about midline
crossing neurons. Here, we characterize normal migration of oculomotor neurons and
analyze the oculomotor phenotypes of Slit1/2 double mutants and Robo 1/2 double
mutants. We find that Slit/Robo repulsion (Slit2 predominant) is important for the
maintenance of the ipsilateral position of OMNs seen in early development. In addition,
Robo2 seems to be the main receptor governing this restriction. Therefore, the
modulation of Slit/Robo signaling serves as an important mechanism governing the
migration of dorsal rectus innervating OMNs. | |
University of Nevada, Reno
