...Steve Seredick; Sarah A. Hutchinson; Liesl Van Ryswyk; Jared C. Talbot; Judith S. Eisen A central problem in development is how fates of closely related cells are segregated. Lineally related motoneurons (MNs) and interneurons (INs) express many genes in common yet acquire distinct fates...

... development remain unclear. Here, we report that a subpopulation of secondary motoneurons extends axons ventrally outside of the neural tubes and rostrocaudally as a fascicle beneath the dorsal aorta (DA) in zebrafish. We tried to clarify the mechanism by which these motoneuron axons grow beneath the DA...

... example of a female-specific neuronal subset. Female post-embryonic Ilp7 neurons are glutamatergic motoneurons innervating the oviduct and are required for female fertility. In males, they are serotonergic/glutamatergic neuromodulatory neurons innervating the seminal vesicle but are not required for male...

...Chao Liu; Weirui Ma; Wenjing Su; Jian Zhang The precise formation of three-dimensional motor circuits is essential for movement control. Within these circuits, motoneurons (MNs) are specified from spinal progenitors by dorsoventral signals and distinct transcriptional programs. Different MN...

... are spinal motor axons navigating towards their peripheral target muscles. Intriguingly, Sema3 proteins are dynamically expressed, forming a code in motoneuron subpopulations, whereas their receptors, the neuropilins, are expressed in most of them. Targeted gain- and loss-of-function approaches in the chick...

... maternal and zygotic contributions of the Hh signaling transducer Smoothened ( MZsmo mutants) and therefore are completely devoid of ligand-dependent pathway activation. Some functional primary motoneurons (PMNs) persist in the absence of Hh signaling, and we find that their induction requires both basal...

... of motoneurons and that this neural guidance function is essential for lymphangiogenesis. Specifically, Netrin 1a secreted by the muscle pioneers at the horizontal myoseptum (HMS) is required for the sprouting of dcc -expressing rostral primary motoneuron (RoP) axons and neighboring axons along the HMS, adjacent...

...Rebecca E. James; Heather T. Broihier The BMP pathway is essential for scaling of the presynaptic motoneuron arbor to the postsynaptic muscle cell at the Drosophila neuromuscular junction (NMJ). Genetic analyses indicate that the muscle is the BMP-sending cell and the motoneuron is the BMP...

... Motoneuron Planar cell polarity Segmental cell migration Muscle specific kinase MuSK wnt11r Dishevelled unplugged In the vertebrate embryonic trunk, neural crest cells delaminate along the entire length of the dorsal neural tube and then enter distinct migratory routes ( Krull...

... analysis of the specification of three of the five pairs of motoneurons in the ascidian Ciona intestinalis and show that despite well-conserved gene expression patterns and embryological outcomes compared with vertebrates, key signalling molecules have adopted different roles. We employed a combination...

... specifically in the trigeminal nerve and in spinal motor and sensory neurons in a Brain-derived neurotrophin factor (BDNF)-dependent manner. Knockdown of Spry3 expression causes an excess of axonal branching in spinal cord motoneurons in vivo. Furthermore, Spry3 inhibits the ability of BDNF to induce filopodia...

... there have been no markers for motoneuron types. Here we show in mice that the synaptic vesicle protein SV2A is selectively localized in motor nerve terminals on slow (type I and small type IIA) muscle fibers; its close relatives, SV2B and SV2C, are present in all motor nerve terminals. SV2A is broadly...

... of a repulsive cue, Toll. We focused on two neighboring muscles, M12 and M13, which are innervated by distinct motoneurons in Drosophila . We found that Toll , which encodes a transmembrane protein with leucine-rich repeats, was preferentially expressed in M13. In Toll mutants, motoneurons that normally...

... (RA) signaling pathways specify the columnar and divisional identities of postmitotic motoneurons (MNs). Here we show that RA signals induce expression of the NET transcriptional regulator Nolz1 in differentiated chick MNs, where it regulates the progressive specification of prospective Lim3-negative...

...Mika Sato-Maeda; Masuo Obinata; Wataru Shoji In zebrafish embryos, each myotome is typically innervated by three primary motoneurons (PMNs): the caudal primary (CaP), middle primary (MiP) and rostral primary (RoP). PMN axons first exit the spinal cord through a single exit point located...

... required for the execution of several stereotyped motor axon pathfinding decisions. The Drosophila genome contains only two MMP homologs, Mmp1 and Mmp2 . We isolated Mmp1 in a misexpression screen to identify molecules required for motoneuron development. Misexpression of either MMP inhibits the regulated...

... and vasculature. Intriguingly, SemaIIIs are also synthesized by neurons during axon pathfinding, but their function as intrinsic cues remains unknown. We have explored the role of Sema3A expression in motoneurons during spinal nerve development. Loss- and gain-of-function in the neural tube of the chick embryo...

...Sarah A. Hutchinson; Sarah E. Cheesman; Laura A. Hale; Jason Q. Boone; Judith S. Eisen The ability of animals to carry out their normal behavioral repertoires requires exquisitely precise matching between specific motoneuron subtypes and the muscles they innervate. However, the molecular mechanisms...

...Louise Parker; Jeremy E. Ellis; Minh Q. Nguyen; Kavita Arora Axon guidance is regulated by intrinsic factors and extrinsic cues provided by other neurons, glia and target muscles. Dawdle (Daw), a divergent TGF-β superfamily ligand expressed in glia and mesoderm, is required for embryonic motoneuron...

...Frauke Meyer; Hermann Aberle Navigation of motoneuronal growth cones toward the somatic musculature in Drosophila serves as a model system to unravel the molecular mechanisms of axon guidance and target selection. In a large-scale mutagenesis screen, we identified piranha , a motor axon guidance...