MAB21L1 modulates gene expression and DNA metabolic processes in the lens placode

Area of Science:

• Developmental Biology
• Genetics
• Ophthalmology

Background:

• Mutations in human MAB21L1 are linked to congenital cerebellar, ocular, craniofacial, and genital (COFG) syndrome.
• Mab21l1-null mice exhibit severe lens formation defects, serving as a model for COFG syndrome.

Purpose of the Study:

• To investigate early, single-cell-level phenotypes in murine Mab21l1-null lens ectoderms.
• To elucidate the molecular mechanisms underlying MAB21L1's role in lens development.

Main Methods:

• Utilized electron microscopy and single-cell RNA sequencing (scRNA-seq) to analyze Mab21l1-null lens ectoderms.
• Performed immunohistochemical analysis to detect endoplasmic reticulum stress.

Main Results:

• Identified endoplasmic reticulum stress in Mab21l1-null lens placodes at the 24- to 26-somite stage.
• Discovered differential gene expression in Mab21l1-null cells, with 131 genes downregulated and 148 upregulated.
• Found downregulation of key lens development genes (Pitx3, Maf, Sfrp2) and enrichment of DNA/nucleotide metabolism genes.

Conclusions:

• MAB21L1 functions as a nuclear factor influencing lens-specific gene expression.
• MAB21L1 is crucial for regulating DNA/nucleotide metabolic processes during lens placode formation.
• These findings provide a deeper understanding of COFG syndrome pathogenesis and lens development.