Which gene is primarily required for lens fiber cell elongation?
Fiber cell elongation transforming cuboidal anterior epithelium into long transparent fibers filling lens vesicle requires L-Maf transcription factor. L-Maf downstream of FGF gradient from retinal to lens pole activates crystallin genes, cytoskeletal remodeling factors, and cell elongation machinery including Prox1 and c-Maf targets. Sox2 initiates placodal stage, Six3 maintains forebrain and eye field, Otx2 specifies retinal pigment epithelium. L-Maf mutant lenses show cuboidal fiber cells failing to elongate, deficient crystallin accumulation, and eventual apoptosis, evidencing its essential
Ref: Gilbert, Developmental Biology, 12th ed., Chapter 12: L-Maf and FGF gradient in lens fiber elongation.
