(040525 revised, 040525 created)
Kawasaki, H., K. Kiguchi, N. Agui and Y. Iwashita (1986)
Ecdysteroid titer and wing development during the pupal-adult transformation of Bombyx mori .
Zool. Sci. 86, 301 -308(1986).
Ecdysteroid in haemolymph was detected at the time of pupation and ecdysteroid titer continued to increase until the end of day 3, and then proceeded to decrease linearly until day 8. An injection of 3.2 ug 20-hydroxyecdysone into a neck ligatured pupa induced normal development of the wing tissue. Mitosis in the wing tissue was observed 16-48 hr after pupation, and a high level of DNA synthesis was found at the stage of 12-40 hr. The scale and adult cuticle began to form at 60 and 96 hr, respectively. Notable elongation of scales occurred from day 4. The specific incorporation of 3H-thymidine into scale cell nuclei was detected 84-96 hr after pupation followed by the enlargement of scale cell nuclei. These results suggest that DNA sysnthesis and mitosis in the wing tissue begin just after pupation at low levels of ecdysteroid, endomitosis and scale formation in the scale cell are induced by a high titer of ecdysteroid, and the formation of the adult wing occurs under conditions of decreasing ecdysteroid titer.
Bombyx mori :English name:
silkworm moth. Japanese name: Kaiko ƒJƒCƒR.
ecdysteroid:
a neck ligatured pupa :
haemolymph: "Blood" of arthropods. Circulatory fluid of insects that have an open circulatory system.