Manifestation of “Giant Egg” Mutant of Bombyx mori (Lepidoptera: Bombycidae)

3. Reciprocal Transplant of Ovaries

Abstract

Reciprocal transplant of an ovarian imaginal disc was performed on day 1 of the fifth instar between full-sib females of giant-egg forming (Ge) and normal-egg forming (+^Ge) larvae segregated by the T (W; 3) Ze/os sch×os sch/Ge cross. When a normal ovary was implanted into a Ge female, the implanted ovary produced eggs that were normal in size, length and width, thus being the same as those derived from untreated normal females. However, the eggs derived from the host's intrinsic ovary were large in comparison to those of the untreated Ge mutant. Reciprocal ovary transplantation resulted in the production of Ge-size eggs from the implanted Ge ovary, and normal-size eggs from the +^Ge ovary of the host. In both cases, the yolk protein content of Ge-size eggs was higher than that of normal-size eggs as seen in the respective controls.