Cre-assisted fine-mapping of neural circuits using orthogonal split inteins
Abstract
Existing genetic methods of neuronal targeting do not routinely achieve the resolution required for mapping brain circuits. New approaches are thus necessary. Here, we introduce a method for refined neuronal targeting that can be applied iteratively. Restriction achieved at the first step can be further refined in a second step, if necessary. The method relies on first isolating neurons within a targeted group (i.e. Gal4 pattern) according to their developmental lineages, and then intersectionally limiting the number of lineages by selecting only those in which two distinct neuroblast enhancers are active. The neuroblast enhancers drive expression of split Cre recombinase fragments. These are fused to non-interacting pairs of split inteins, which ensure reconstitution of active Cre when all fragments are expressed in the same neuroblast. Active Cre renders all neuroblast-derived cells in a lineage permissive for Gal4 activity. We demonstrate how this system can facilitate neural circuit-mapping in Drosophila.
Data availability
Data generated during this study are included in the manuscript and supporting files. Source data files have been provided for Figure 2I
Article and author information
Author details
Funding
National Institute of Mental Health (ZIA-MH002800)
- Benjamin H White
National Institute of Neurological Disorders and Stroke (ZIA-NS002820-26)
- Ward F Odenwald
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- K VijayRaghavan, National Centre for Biological Sciences, Tata Institute of Fundamental Research, India
Version history
- Received: October 24, 2019
- Accepted: April 11, 2020
- Accepted Manuscript published: April 14, 2020 (version 1)
- Version of Record published: May 12, 2020 (version 2)
Copyright
This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
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