Spatiotemporal Expression of Transcription Factors Regulating Interneuron Development in Zebrafish
Abstract number :
3.09
Submission category :
1. Basic Mechanisms / 1F. Other
Year :
2024
Submission ID :
346
Source :
www.aesnet.org
Presentation date :
12/9/2024 12:00:00 AM
Published date :
Authors :
Presenting Author: Bonnie Zhu, BS – University of California, San Francisco
Scott Baraban, PhD – UCSF
Rationale: GABAergic interneurons are primarily generated from embryonic subpallial progenitor domains e.g., medial and caudal ganglionic eminences. Combinatorial interactions of transcription factors regulate this early interneuron differentiation and migration. For example,NKX2-1 controls regional identity in MGE and, withLHX6, is necessary to specify differentiation to mature somatostatin- and parvalbumin-expressing interneurons. ARX, a transcription factor linked to epilepsy, autism, and intellectual disability, is also expressed in migrating MGE progenitor cells. Previous ARX studies employed mice or human stem cell models. Here, we studied early interneuron development in CRISPR-generated arx zebrafish (Danio rerio) models.
Methods:
Wild-type, dlx5a/6a-GFP or arx deficient zebrafish (12 hours post-fertilization, 1 to 6-days post-fertilization, dpf) were used for all studies. Hybridization chain reaction (HCR) was used for multiplexed, high-resolution RNA imaging in whole-mount zebrafish. Gene probes: nkx2.1, lhx6a, calb2a/2b, dlx5a/6a, couptFII, sst1.1, pvalb6, arxa and arxb. Images were obtained using a Nikon confocal or a Bruker TruLive3D Imager light sheet microscope.
Results: nkx2.1 expression was first observed in prosencephalon (forebrain) at 12 hpf and persisted to 2 dpf. At 1-2 dpf, lhx6a was expressed in a more restricted manner but often overlapped with nxk2.1; calb2a/2b and couptFII genes were expressed in prosencephalon and olfactory bulb. At 3 dpf, sparse dlx5a/6a expression in prosencephalon and mesencephalon overlapped with lhx6 consistent with roles of Dlx homeobox genes in GABAergic interneuron development. At 5-6 dpf, scattered single cell sst1.1 expression was seen in prosencephalon and mesencephalon (optic tectum) and in cell clusters of rhombencephalon (cerebellum). Non-overlapping pvalb6 expression in prosencephalon (thalamus) cell clusters and single mesencephalon (optic tectum) cells was also noted. arxa was first observed in prosencephalon at 1 dpf and overlapped with ohnologue arxb expression through 5 dpf.
Conclusions: Our findings reveal that zebrafish share basic rules for interneuron development. Further analysis of interneuron development in zebrafish models (Griffin et al., 2021) will substantially advance our understanding of a wide variety of neurodevelopmental epilepsies.
Funding:
This work was supported by NIH/NINDS grant R01-NS096976 (to SCB).
Basic Mechanisms