title: The POU transcription factor UNC-86 controls the timing and ventral guidance of Caenorhabditis elegans axon growth.
abstract: The in vivo mechanisms that coordinate the timing of axon growth and guidance are not well understood. In the Caenorhabditis elegans hermaphrodite specific neurons (HSNs), the lin-4 microRNA controls the stage of axon initiation independent of the UNC-40 and SAX-3 ventral guidance receptors. lin-4 loss-of-function mutants exhibit marked delays in axon outgrowth, while lin-4 overexpression leads to precocious growth in the L3 larval stage. Here, we show that loss of the POU transcription factor UNC-86 not only results in penetrant ventral axon growth defects in in the HSNs, but also causes processes to extend in the L1, three stages earlier than wild-type. This temporal shift is not dependent on UNC-40 or SAX-3, and does not require the presence of lin-4. We propose that unc-86(lf) HSN axons are misguided due to the temporal decoupling of axon initiation and ventral guidance responses.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Olsson-Carter
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Slack
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism* / Q000502:physiology*; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D050809:POU Domain Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; D018398:Homeodomain Proteins; D050809:POU Domain Factors; C081539:unc-86 protein, C elegans