. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. AUTOTOMY-INDUCED MOLTING DELAY 100. 0 8 9 10 11 12 DAYS AFTER FEEDING 13 FIGURE 7. A graded response of cockroaches to ecdysone. Graded doses of ecdysone (1, 2, 4, and 8 /tig/animal; triangle, X, cross, square, respectively) were injected into groups of 25 limb autotomized test animals. The cumulative percentage of each group which molted by a given time is plotted. In a control autotomized group injected with saline (open circle) 76 out of 77 had not molted by day 13. An unautotomized control group (solid circle) of 10
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. AUTOTOMY-INDUCED MOLTING DELAY 100. 0 8 9 10 11 12 DAYS AFTER FEEDING 13 FIGURE 7. A graded response of cockroaches to ecdysone. Graded doses of ecdysone (1, 2, 4, and 8 /tig/animal; triangle, X, cross, square, respectively) were injected into groups of 25 limb autotomized test animals. The cumulative percentage of each group which molted by a given time is plotted. In a control autotomized group injected with saline (open circle) 76 out of 77 had not molted by day 13. An unautotomized control group (solid circle) of 100 animals is included to show the normal time of molting. would already be committed to molt and the resulting rising titer of ecdysone would shut off any regeneration which started. Thus, the all or none nature of regeneration in cockroaches is explained. The length of the delay of molting was shown previously, as well as in the present study, to be specific for each type of regenerate and thoracic segment. The simplest explanation of the control of the length of delay is that it is determined by the hemiganglion serving each leg. It was shown above that the length of the delay associated with each regenerating limb is independent of each other regenerating limb. This suggests that there is an independent delay-determining process in the hemiganglion serving each leg. This might involve the neurons whose synthetic activities have been shown to be activated during regeneration (Cohen and Jacklet, 1965), or those which play an active part in the coxal muscle regression during limb regeneration (Shapiro, 1976). Differences in the neurons affected by tarsal and femur-tibia-tarsal autotomy could control the observed dif- ference in delay due to level of autotomy. The end of the delay associated with each leg and level of autotomy inde- pendently releases the brain from inhibition and when all autotomized limbs have stopped their delay signals, the brain promptly initiates a molting
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
