. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. JUVENILE HORMONE ACTION IN MANDUCA 573 0> S 4 h- 3 h- CL M— o 2 o Q. 2345 Weight (g) at time of allatectomy FIGURE 3. The timing of PTTH release in final instar larvae which were allatectomized at various weights and subsequently starved. The day of allatectomy is designated as day 0. The bars indicate the 95% confidence limits of the mean. Each point represents approximately 15 larvae. and Williams, 1974b). I have investigated this discrepancy in further detail by allatectomizing larvae at various weights, isolating the
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. JUVENILE HORMONE ACTION IN MANDUCA 573 0> S 4 h- 3 h- CL M— o 2 o Q. 2345 Weight (g) at time of allatectomy FIGURE 3. The timing of PTTH release in final instar larvae which were allatectomized at various weights and subsequently starved. The day of allatectomy is designated as day 0. The bars indicate the 95% confidence limits of the mean. Each point represents approximately 15 larvae. and Williams, 1974b). I have investigated this discrepancy in further detail by allatectomizing larvae at various weights, isolating the resulting individuals without food, and noting the day on which PTTH release occurred. Figure 3 summarizes these experiments and shows that the release of PTTH occurred progressively later as larvae were allatectomized at lower weights. PTTH release occurred approximately and clays after allatectomy of and gram larvae, respectively. These times correspond fairly well with the period required for the disappearance of JH effects in 50% of the isolated abdomens of larvae of similar weights (Figure 2). All allatectomized larvae exposed their dorsal vessel and proceeded to deposit a perfect pupal cuticle. Forty seven percent (n = 58) of the starved, sham- operated control larvae weighing grams molted to larval-pupal inter- mediates. PTTH release in these control larvae occurred predominantly on days 5-8 after the operation. Few sham operated larvae weighing less than three grams survived to molt, death occurring 7-12 days after the operation. Parabiotic preparations Intact small 5th instar larvae, weighing grams were parabiosed to large 5th instar larvae weighing grams. Induced by the secretion of PTTH and ecdysone of the large larva, the small partner invariably molted into a nearly perfect additional larval instar except for the absence of crochets on the prolegs and the presence of small patches of pupal cuticle on the clypeus and. Pleas
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
