ABSTRACT
Synapse-associated protein 1 (Syap1) is the mammalian homologue of synapse-associated protein of 47 kDa (Sap47) in Drosophila. Genetic deletion of Sap47 leads to deficiencies in short-term plasticity and associative memory processing in flies. In mice, Syap1 is prominently expressed in the nervous system, but its function is still unclear. We have generated Syap1 knockout mice and tested motor behaviour and memory. These mice are viable and fertile but display distinct deficiencies in motor behaviour. Locomotor activity specifically appears to be reduced in early phases when voluntary movement is initiated. On the rotarod, a more demanding motor test involving control by sensory feedback, Syap1-deficient mice dramatically fail to adapt to accelerated speed or to a change in rotation direction. Syap1 is highly expressed in cerebellar Purkinje cells and cerebellar nuclei. Thus, this distinct motor phenotype could be due to a so-far unknown function of Syap1 in cerebellar sensorimotor control. The observed motor defects are highly specific since other tests in the modified SHIRPA exam, as well as cognitive tasks like novel object recognition, Pavlovian fear conditioning, anxiety-like behaviour in open field dark-light transition and elevated plus maze do not appear to be affected in Syap1 knockout mice.
Footnotes
Competing interests
The authors declare no competing or financial interests.
Author contributions
Conceptualization: M.S., R.B., E.B.; Methodology: C.R.v.C, D.S., T.R., R.B.; Formal analysis: C.R.v.C.; Investigation: C.R.v.C., D.S.; Resources: T.R., M.S.; Data curation: C.R.v.C., R.B.; Writing - original draft: C.R.v.C., R.B., E.B.; Writing - review & editing: C.R.v.C., D.S., T.R., M.S., R.B., E.B.; Supervision: M.S., R.B., E.B.; Funding acquisition: M.S., R.B., E.B.
Funding
This work was supported by German Research Foundation (DFG) [project number 44541416–TRR58–A10 to R.B. and M.S.]; by the Bundesministerium für Bildung und Forschung [Dystract TP6 to M.S.]; and by the INFRAFRONTIER-I3 project Capacities Specific Programme [EU contract Grant Agreement Number 312325, EC FP7 to E.B.]. This publication was also funded by the DFG and the University of Wuerzburg in the funding programme Open Access Publishing.
Supplementary information
Supplementary information available online at http://bio.biologists.org/lookup/doi/10.1242/bio.042366.supplemental
- Received February 6, 2019.
- Accepted May 13, 2019.
- © 2019. Published by The Company of Biologists Ltd
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