Hypothesis and Theory ARTICLE
The Tenets of Teneurin: Conserved Mechanisms Regulate Diverse Developmental Processes in the Drosophila Nervous System
- 1Department of Neuroscience, Thomas Jefferson University, United States
To successfully integrate a neuron into a circuit, a myriad of developmental events must occur correctly and in the correct order. Neurons must be born and grow out towards a destination, responding to guidance cues to direct their path. Once arrived, each neuron must segregate to the correct sub-region before sorting through a milieu of incorrect partners to identify the correct partner with which they can connect. Finally, the neuron must make a synaptic connection with their correct partner; a connection that needs to be broadly maintained throughout the life of the animal while remaining responsive to modes of plasticity and pruning. Though many intricate molecular mechanisms have been discovered to regulate each step, recent work showed that a single family of proteins, the Teneurins, regulates a host of these developmental steps in Drosophila – an example of biological adaptive reuse. Teneurins first influence axon guidance during early development. Once neurons arrive in their target regions, Teneurins enable partner matching and synapse formation in both the central and peripheral nervous systems. Despite these diverse processes and systems, the Teneurins use conserved mechanisms to achieve these goals, as defined by two tenets: 1) transsynaptic interactions with each other and 2) membrane stabilization via an interaction and regulation of the cytoskeleton. These processes are further distinguished by 1) the nature of the transsynaptic interaction – homophilic interactions (between the same Teneurins) to engage partner matching and heterophilic interactions (between different Teneurins) to enable synaptic connectivity and the proper apposition of pre- and postsynaptic sites and 2) the location of cytoskeletal regulation (presynaptic cytoskeletal regulation in the CNS and postsynaptic regulation of the cytoskeleton at the NMJ). Thus, both the roles and the mechanisms governing them are conserved across processes and synapses. In this review, we will highlight the contributions of Drosophila synaptic biology to our understanding of the Teneurins and discuss the mechanistic conservation that allows the Teneurins to achieve common neurodevelopmental goals. Finally, we will posit the next steps for understanding how this remarkably versatile family of proteins functions to control multiple distinct events in the creation of a nervous system.
Keywords: Teneurin, Drosophila, synapse formation, Partner matching, Cytoskeleton, NMJ, Olfaction, Spectrin
Received: 19 Oct 2018;
Accepted: 11 Jan 2019.
Edited by:Antony J. Boucard, Centro de Investigación y de Estudios Avanzados (CINVESTAV), Mexico
Reviewed by:Pei-San Tsai, University of Colorado Boulder, United States
Robert Hindges, King's College London, United Kingdom
Copyright: © 2019 DePew, Aimino and Mosca. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Timothy J. Mosca, Thomas Jefferson University, Department of Neuroscience, Philadelphia, 19107, Pennsylvania, United States, firstname.lastname@example.org