dlx and sp6-9 Control optic cup regeneration in a prototypic eye

Area of Science:

• Developmental biology
• Regenerative medicine
• Ophthalmology

Background:

• Optic cups are crucial eye structures found across diverse species.
• Understanding optic cup formation is key to studying eye development and regeneration.
• Planarians offer a model system for investigating organ regeneration due to their neoblast stem cells.

Purpose of the Study:

• To investigate the genetic control of optic cup formation and regeneration in planarians.
• To identify key genes involved in the development of the optic cup structure.
• To elucidate the role of progenitor cell migration in planarian eye regeneration.

Main Methods:

• Utilized planarian prototypic eyes as a model system.
• Employed RNA interference (RNAi) to study gene function (sp6-9 and dlx).
• Observed cell migration and differentiation from neoblasts during regeneration.

Main Results:

• Identified sp6-9 and dlx transcription factors expressed specifically in the optic cup.
• RNAi knockdown of sp6-9 and dlx genes inhibited optic cup formation during regeneration.
• Demonstrated that optic cup formation follows progenitor cell migration from neoblasts.
• Linked gene function to the failure of generating early optic cup progenitors.

Conclusions:

• The genes dlx and sp6-9 are essential for optic cup formation in planarians.
• These genes function as a module in appendage development, now shown to be critical for eye components.
• Planarian eye regeneration involves cell movement separating specification from morphogenesis, regulated by dlx and sp6-9.