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Failure of Lens Formation after Extirpation of the Optic Vesicle in early Tail – Bud stages

 

Procedure :

Before starting the operation, locate the optic vesicle on a normal embryo and expose it by removing the epidermis in order to obtain a clear picture of the topographic relationships.

 

  • 1. Remove all membranes. Place an embryo in a groove in an agar dish together with a well fitting glass bridge.
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  • 2. With the glass needle, cut out a square flip of epidermis overlying the optic vesicle, on three sides only, as in Fig. 2.

  • Figure 2

    3. Reflect the flap and extirpate the optic vesicle at its base. Its is essential to avoid injury or curling of the prospective lens epithelium. Turn the flip back; very cautiously flatten it out with a hair loop of glass needle, so that the edges come in contact with the adjacent epidermis, and place a glass bridge over it. Control the healing during the following 20 – 30 minutes.

  • 4. Record the details of the operation and transfer the embryo to a dish with dilute medium. Operate several embryos in the same way.
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  • 5. Fix the swimming larvae several days later in 10% formaldehyde. Carefully dissect the skin over both eyes and notice the left lens. The lens becomes opaque through fixation and can be easily recognized.