A zebrafish model of foxe3 deficiency demonstrates lens and eye defects with dysregulation of key genes involved in cataract formation in humans
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The Forkhead box E3 (FOXE3) gene encodes a transcription factor with a forkhead/winged helix domain that is critical for development of the lens and anterior segment of the eye. Monoallelic and biallelic deleterious sequence variants in FOXE3 cause aphakia, cataracts, sclerocornea and microphthalmia in humans. We used clustered regularly interspaced short palindromic repeats/Cas9 injections to target the foxe3 transcript in zebrafish in order to create an experimental model of loss of function for this gene. Larvae that were homozygous for an indel variant, c.296_300delTGCAG, predicting p.(Val99Alafs*2), demonstrated severe eye defects, including small or absent lenses and microphthalmia. The lenses of the homozygous foxe3 indel mutants showed more intense staining with zl-1 antibody compared to control lenses, consistent with increased lens fiber cell differentiation. Whole genome transcriptome analysis (RNA-Seq) on RNA isolated from wildtype larvae and larvae with eye defects that were putative homozygotes for the foxe3 indel variant found significant dysregulation of genes expressed in the lens and eye whose orthologues are associated with cataracts in human patients, including cryba2a, cryba1l1, mipa and hsf4. Comparative analysis of this RNA-seq data with iSyTE data identified several lens-enriched genes to be down-regulated in foxe3 indel mutants. We also noted upregulation of lgsn and crygmxl2 and downregulation of fmodb and cx43.4, genes that are expressed in the zebrafish lens, but that are not yet associated with an eye phenotype in humans. These findings demonstrate that this new zebrafish foxe3 mutant model is highly relevant to the study of the gene regulatory networks conserved in vertebrate lens and eye development.
Library preparation and QCs for sequencing was conducted by Yanxia Hao, Jim McGuire and Natasha Carli, PhD, at the Gladstone Genomics Core.
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Conflict of interest
None of the authors have potential conflicts of interest to disclose.
Human rights and animal participants
All procedures performed in studies involving animals were in accordance with the ethical standards of the institution or practice at which the studies were conducted. This article does not contain any studies with human participants performed by any of the authors.
- Chao R, Nevin L, Agarwal P, Riemer J, Bai X, Delaney A, Akana M, JimenezLopez N, Bardakjian T, Schneider A, Chassaing N, Schorderet DF, FitzPatrick D, Kwok PY, Ellgaard L, Gould DB, Zhang Y, Malicki J, Baier H, Slavotinek A (2010) A male with unilateral microphthalmia reveals a role for TMX3 in eye development. PLoS One 5:e10565CrossRefGoogle Scholar
- Siddam AD, Gautier-Courteille C, Perez-Campos L, Anand D, Kakrana A, Dang CA, Legagneux V, Méreau A, Viet J, Gross JM, Paillard L, Lachke SA (2018) The RNA-binding protein Celf1 post-transcriptionally regulates p27Kip1 and Dnase2b to control fiber cell nuclear degradation in lens development. PLoS Genet 14(3):e1007278CrossRefGoogle Scholar