gdnf affects early diencephalic dopaminergic neuron development through regulation of differentiation‐associated transcription factors in zebrafish
Document Type
Article
Publication Date
1-1-2021
Abstract
Glial cell line-derived neurotrophic factor (GDNF) has been reported to enhance dopaminergic neuron survival and differentiation in vitro and in vivo, although those results are still being debated. Glial cell line-derived neurotrophic factor (gdnf) is highly conserved in zebrafish and plays a role in enteric nervous system function. However, little is known about gdnf function in the teleost brain. Here, we employed clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 to impede gdnf function in the maintenance of dopaminergic neuron development. Genotyping of gdnf crispants revealed successful deletions of the coding region with various mutant band sizes and down-regulation of gdnf transcripts at 1, 3 and 7 day(s) post fertilization. Notably, ~20% reduction in ventral diencephalic dopaminergic neuron numbers in clusters 8 and 13 was observed in the gdnf-deficient crispants. In addition, gdnf depletion caused a modest reduction in dopaminergic neurogenesis as determined by 5-ethynyl-2'-deoxyuridine pulse chase assay. These deleterious effects could be partly attributed to deregulation of dopaminergic neuron fate specification-related transcription factors (otp, lmx1b, shha, and ngn1) in both crispants and established homozygous mutants with whole mount in-situ hybridization (WISH) on gdnf mutants showing reduced otpb and lmx1b.1 expression in the ventral diencephalon. Interestingly, locomotor function of crispants was only impacted at 7 dpf, but not earlier. Lastly, as expected, gdnf deficiency heightened crispants vulnerability to 1-methyl-4-phenylpyridinium toxic insult. Our results suggest conservation of teleost gdnf brain function with mammals and revealed the interactions between gdnf and transcription factors in dopaminergic neuron differentiation. (Figure presented.). © 2020 International Society for Neurochemistry
Keywords
crispants, differentiation, dopaminergic neurons, gdnf, knock-out, neurogenesis, transcription factors, ventral diencephalon
Divisions
fac_med
Funders
Malaysian Ministry of Higher Education Fundamental Research Grant Scheme (FP027‐2014A),Natural Sciences and Engineering Research Council of Canada grant (121795),University of Malaya Postgraduate Research grant (PG246‐2015B),Special Research Assistance grant (BKS064‐2017),Research University Grant (Faculty of Medicine RU) (GPF014C‐2018),Malaysian Ministry of Higher Education “MyPhD programme”,Malaysian Society of Neurosciences Education Grant (ID: 02246). gdnf + SEM
Publication Title
Journal of Neurochemistry
Volume
156
Issue
4
Publisher
Wiley