1. Gsx2, but not Gsx1, is necessary for early forebrain patterning and long‐term survival in zebrafish.
- Author
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Coltogirone, Rebecca A., Sherfinski, Emma I., Dobler, Zoë A., Peterson, Sarah N., Andlinger, Abreanne R., Fadel, Lindsay C., Patrick, Regina L., and Bergeron, Sadie A.
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PROSENCEPHALON ,CENTRAL nervous system ,GENE expression ,BRACHYDANIO ,GENE regulatory networks - Abstract
Background: Homeobox transcription factor encoding genes, genomic screen homeobox 1 and 2 (gsx1 and gsx2), are expressed during neurodevelopment in multiple vertebrates. However, we have limited knowledge of the dynamic expression of these genes through developmental time and the gene networks that they regulate in zebrafish. Results: We confirmed that gsx1 is expressed initially in the hindbrain and diencephalon and later in the optic tectum, pretectum, and cerebellar plate. gsx2 is expressed in the early telencephalon and later in the pallium and olfactory bulb. gsx1 and gsx2 are co‐expressed in the hypothalamus, preoptic area, and hindbrain, however, rarely co‐localize in the same cells. gsx1 and gsx2 mutant zebrafish were made with TALENs. gsx1 mutants exhibit stunted growth, however, they survive to adulthood and are fertile. gsx2 mutants experience swim bladder inflation failure that prevents survival. We also observed significantly reduced expression of multiple forebrain patterning distal‐less homeobox genes in mutants, and expression of foxp2 was not significantly affected. Conclusions: This work provides novel tools with which other target genes and functions of Gsx1 and Gsx2 can be characterized across the central nervous system to better understand the unique and overlapping roles of these highly conserved transcription factors. Key Findings: gsx1 and gsx2 expression is dynamic during embryonic and larval stages of neurodevelopment in zebrafish, and gsx1 expression appears to be in differentiating neurons based on their morphology and position.gsx1 and gsx2 are expressed together in several developing brain regions, however, they rarely colocalize in the same cells.Early forebrain patterning in gsx1 mutants appears normal, and Gsx1 might partially compensate for loss of Gsx2 function as more severe forebrain gene expression loss is observed in gsx1 and gsx2 mutants compared to gsx2 mutants in some instances.Complementation testing between different gsx1 or gsx2 mutant alleles shows that mutant phenotypes arise from altered gsx1 or gsx2 function. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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