Overlapping enhancer activity robustly regulates rax expression during ocular development in zebrafish

Five novel ocular enhancers in zebrafish (Danio rerio) drive rax-like spatiotemporal expression at three key eye-development stages, with two enhancers overlapping endogenous rax transcripts.

• Why it matters: rax is an early eye-field transcription factor essential for optic vesicle evagination, but the cis-regulatory elements controlling its dynamic expression are not well defined.
• What they did: The study identified five enhancers, tested their activity during development, characterized two enhancers for transcript-level overlap with endogenous rax, and created enhancer deletion lines to perturb the rax GRN.
• The result: The rax gene regulatory network is largely robust to individual and combinatorial enhancer perturbations, yet GRN disruption produces rax-associated ocular abnormalities, including microphthalmia and anophthalmia.

AI summary of the abstract · may contain errors · not medical advice · read the paper.