Axon guidance pathways and the control of gene expression

Abstract

Axons need to be properly guided to their targets to form synaptic connections, and this requires interactions between highly conserved extracellular and transmembrane ligands and their cell surface receptors. The majority of studies on axon guidance signaling pathways have focused on the role of these pathways in rearranging the local cytoskeleton and plasma membrane in growth cones and axons. However, a smaller body of work has demonstrated that axon guidance signaling pathways also control gene expression via local translation and transcription. Recent studies on axon guidance ligands and receptors have begun to uncover the requirements for these alternative mechanisms in processes required for neural circuit formation: axon guidance, synaptogenesis, and cell migration. Understanding the mechanisms by which axon guidance signaling regulates local translation and transcription will create a more complete picture of neural circuit formation, and they may be applied more broadly to other tissues where axon guidance ligands and receptors are required for morphogenesis. Developmental Dynamics 247:571-580,

Keratan sulfate (KS)‐proteoglycans and neuronal regulation in health and disease: the importance ofKS‐glycodynamics and interactive capability with neuroregulatory ligands

“…In the visual system, Robo2 plays a dominant role in retinal ganglion cell targeting critical to the formation of synaptic interconnections (Plachez et al 2008;Hocking et al 2010). This process requires interactions between extracellular and transmembrane ligands, cell surface receptors, and rearrangement of the local cytoskeleton and plasma membrane of growth cones (Russell and Bashaw 2018). Slit2 also stimulates angiogenesis which is regulated by ephrin-A1 during neuronal migration (Fujiwara et al 2006;Dunaway et al 2011;Yadav and Narayan 2014).…”

Cell surface molecule, Klingon, mediates the refinement of synaptic specificity in the Drosophila visual system

“…The formation of a functional neuronal circuit requires axons to recognize and connect with their correct target neurons (Hakeda‐Suzuki & Suzuki, ; Russell & Bashaw, ). Once this occurs, the connection is stabilized, and initial steps of synapse formation begin (Akin & Zipursky, ; Hakeda‐Suzuki, Takechi, Kawamura, & Suzuki, ).…”

Transplantation of photoreceptor precursor cells into the retina of an adult Drosophila

“…Many molecules required for axon guidance and/or extension of the Drosophila visual system have been reported (Hakeda-Suzuki & Suzuki, 2014;Russell & Bashaw, 2017). In addition, Drosophila photoreceptors extend long axons toward the optic lobes, which are simple compared to mammals, but still have enough functional and fine neural structures.…”

“…In addition, Drosophila photoreceptors extend long axons toward the optic lobes, which are simple compared to mammals, but still have enough functional and fine neural structures. Many molecules required for axon guidance and/or extension of the Drosophila visual system have been reported (Hakeda-Suzuki & Suzuki, 2014;Russell & Bashaw, 2017). By using genetic tools, we can easily manipulate these genes and perform screenings to find the appropriate conditions for transplantation.…”