. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. METAMORPHOSIS OF DROS/'////.. I DISCS 49 might be necessary for metamorphosis. Therefore in I. ecdysterone wa> injected in multiple as well as single doses into adult abdomens containing discs. The total amount of ecdysterone injected in both cases was equal. The discs were transplanted into female hosts on day one. About twenty-four hours later, all of the experimental and control animals were injected \vith ecdysterone. One ex- perimental group received a total dose of //.g/g, and a second group, a total dos
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. METAMORPHOSIS OF DROS/'////.. I DISCS 49 might be necessary for metamorphosis. Therefore in I. ecdysterone wa> injected in multiple as well as single doses into adult abdomens containing discs. The total amount of ecdysterone injected in both cases was equal. The discs were transplanted into female hosts on day one. About twenty-four hours later, all of the experimental and control animals were injected \vith ecdysterone. One ex- perimental group received a total dose of //.g/g, and a second group, a total dose of 720 ng/g. The results are shown in Table 1. Although the total amount deliv- ered in single- and multiple-dose experiments was the same, discs receiving the total dose in instalments enlarged more and secreted cuticle more often than did. Fie,i-RE 1. Adult structures produced by imaginal leg discs induced to metamorphose by ecdysterone; (A) A metamorphosed leg, note everted tarsus; (B) Sensilla campaniformia of the femur; (C) Sensilla trichodea of the coxa; (D) Claw organ, note pupal cuticle enveloping the tarsus; (E) Sexcomb teeth, typical of the male basitarsus. Abbreviations: pc, pupal cuti- cle; sc, sensilla campaniformia; set, sex comb teeth; st, sensilla trichodea; ta, tarsus; ta5, fifth tarsal segment; u, unguis. discs receiving the same amount of hormone in one dose. Apparently, ecdysterone is necessary as a sustained stimulus for metamorphosis, and not merely as a trigger for development. No bristles, hairs or sensillae were formed in Series I. .Scr/(\v //: Cyasterone Cyasterone is an analogue of ecdysone extracted from plants which appears to be more potent than ecdysterone in certain systems (Williams, 1(>(>S). Table II shows that a single dose of Cyasterone stimulated a greater increase in size and a higher frequency of cuticle secretion than an equivalent dose of ecdysterone. The discs treated with one 720 /xg/g dose of cyasterone were larger than discs
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
