A wilde-type eye disk transplanted to a claret host before 80 hours after egg-laying (25° C.) gives rise to an eye with pigmentation like that of claret. If the same transplantation is made shortly before puparium formation (about 106 hours after egg-laying), the resulting implant is phenotypically close to wild type. These results are interpreted by assuming that a specific diffusible substance (ca+ substance) necessary for wild-type eye colour, moves from the body to the eye in a wild-type fly during some period between 80 and 106 hours after egg-laying, and that transplantation, after this critical time, of an eye from such a fly to a host which cannot supply the substance, does not modify the normal course of pigment development.
The relation of this critical time to experiments previously published is considered.
Tests for the production ofca+ substance by the ovaries of wild-type flies gave negative results.
Volume 100, 2021
Continuous Article Publishing mode
Click here for Editorial Note on CAP Mode