PUBLICATION

Knockout of the fcsk gene in zebrafish causes neurodevelopmental defects

Authors
Liu, Z.X., Zou, T.T., Liu, H.H., Jia, H.B., Zhang, X.Q.
ID
ZDB-PUB-250307-29
Date
2025
Source
Zoological research   46: 313324313-324 (Journal)
Registered Authors
Zhang, Xianqin
Keywords
Behavior, Congenital disorders of glycosylation, RNA sequencing, Zebrafish, fcsk
MeSH Terms
  • Phosphotransferases (Alcohol Group Acceptor)/genetics
  • Phosphotransferases (Alcohol Group Acceptor)/metabolism
  • Neurodevelopmental Disorders/genetics
  • CRISPR-Cas Systems
  • Gene Knockout Techniques
  • Animals
  • Zebrafish*/genetics
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
PubMed
40049660 Full text @ Zool Res
Abstract
Congenital disorders of glycosylation (CDG) are a cluster of monogenic disorders resulting from defects in glycosylation. FCSK encodes fucokinase, an enzyme that catalyzes the phosphorylation of L-fucose to generate fucose-1-phosphate, an important step in fucosylation. Mutations in FCSK lead to CDG with an autosomal recessive inheritance pattern, primarily manifesting as developmental delay, hypotonia, and brain abnormalities. However, no fcsk mutant animal models have yet been established. This study constructed the first fcsk knockout ( fcsk-/-) zebrafish model using CRISPR/Cas9 technology. Notably, fcsk-/- zebrafish exhibited impaired growth, characterized by delayed epiboly and DNA accumulation during early embryonic development, as well as brain atrophy in adulthood. Larval-stage fcsk-/- zebrafish displayed locomotor deficits and increased susceptibility to pentylenetetrazole-induced seizures. In adulthood, fcsk-/- zebrafish showed neurodevelopmental abnormalities, including increased anxiety, decreased aggression, reduced social preference, and impaired memory. Additionally, total protein fucosylation was markedly reduced in fcsk-/- zebrafish, accompanied by decreased expression of pofut2, which encodes protein O-fucosyltransferase 2, an enzyme involved in the fucosylation salvage pathway. Apoptotic activity was elevated in the midbrain-hindbrain boundary (MHB) of fcsk-/- zebrafish. Supplementation with GDP-L-fucose or the human FCSK gene restored developmental defects and total protein fucosylation in fcsk-/- zebrafish. RNA sequencing revealed dysregulated gene expression associated with glycosylation, apoptosis, and neurodegenerative diseases. These findings suggest that fcsk-/- zebrafish exhibit neurodevelopmental disorders, providing the first fcsk gene knockout animal model and offering a platform for investigating the molecular underpinnings of the disease and facilitating drug screening efforts.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping