Regeneration of the eye margin in Periplaneta americana (Insecta, Blattodea)

The regulative ability of the proliferative zone of the insect eye margin has been investigated in larval Periplaneta americana. After sections of the eye margin are removed the eye nevertheless recovers to form a normal shape. Using chimaeras of lavender and wild-type animals we were able to show that the margin can regenerate from the differentiated parts of the eye. When differentiated eye tissue is confronted with epidermis from the head capsule adjacent to the proliferative zone (the vertex), the regenerated margin always forms from the eye. There is no evidence that intervening levels can be intercalated between host and graft tissues when sections of the eye margin are moved to new circumferential levels. However, in that situation differences between tissues from non-adjacent circumferential positions lead to the rounding up of the graft and it fails to develop normally.