The lens placode is affected by the chordamesoderm making it to invaginate and forms the optic cup composed by an outer layer of neural retina and inner layer the pigmented retina that will unite and form the optic stalk.
22.
For example, Foxg1, also called Brain-Factor 1, and Foxd1, also called Brain Factor 2, are winged-helix transcription factors that are expressed in the nasal and temporal optic cups asn the optic vesicles being to evaginate from the neural tube.
23.
It is of interest to note that research has shown isolating the optic cup from neighboring tissue after completed invagination in tissue culture medium can lead to the development of most major parts of the eye, including photoreceptors, ganglion cells, bipolar cells, horizontal cells, amacrine cells and Muller glia.
