ZFIN ID: ZDB-PUB-150311-3
A Genome-wide Screen Identifies PAPP-AA-Mediated IGFR Signaling as a Novel Regulator of Habituation Learning
Wolman, M.A., Jain, R.A., Marsden, K.C., Bell, H., Skinner, J., Hayer, K.E., Hogenesch, J.B., Granato, M.
Date: 2015
Source: Neuron   85(6): 1200-11 (Journal)
Registered Authors: Granato, Michael, Jain, Roshan, Marsden, Kurt, Wolman, Marc
Keywords: none
MeSH Terms:
  • Animals
  • Behavior, Animal
  • Female
  • Genetic Testing/methods
  • Genome, Archaeal*
  • Learning/physiology*
  • Mutation/genetics*
  • Neurons/metabolism
  • Pregnancy
  • Pregnancy-Associated Plasma Protein-A/genetics
  • Pregnancy-Associated Plasma Protein-A/metabolism*
  • Receptor, IGF Type 1/genetics
  • Receptor, IGF Type 1/metabolism*
  • Signal Transduction/genetics*
  • Zebrafish/metabolism*
PubMed: 25754827 Full text @ Neuron
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ABSTRACT
Habituation represents a fundamental form of learning, yet the underlying molecular genetic mechanisms are not well defined. Here we report on a genome-wide genetic screen, coupled with whole-genome sequencing, that identified 14 zebrafish startle habituation mutants including mutants of the vertebrate-specific gene pregnancy-associated plasma protein-aa (pappaa). PAPP-AA encodes an extracellular metalloprotease known to increase IGF bioavailability, thereby enhancing IGF receptor signaling. We find that pappaa is expressed by startle circuit neurons, and expression of wild-type but not a metalloprotease-inactive version of pappaa restores habituation in pappaa mutants. Furthermore, acutely inhibiting IGF1R function in wild-type reduces habituation, while activation of IGF1R downstream effectors in pappaa mutants restores habituation, demonstrating that pappaa promotes learning by acutely and locally increasing IGF bioavailability. In sum, our results define the first functional gene set for habituation learning in a vertebrate and identify PAPPAA-regulated IGF signaling as a novel mechanism regulating habituation learning.
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