. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ARTEMIA MORPHOGENESIS 267 synthesis (arrows on Fig. 1). The threshold increased with increasing AMP con- centrations. The effect of puromycin, an inhibitor of protein synthesis, also depended on the AMP:CMP ratio of the diet (Fig. 2-5). With a 60 mg % AMP concentration, puromycin action decreased with increasing CMP concentration above the con- centration found necessary for maximum RNA synthesis. Excess CMP did not induce supernumerary gonopodes in the presence of the antibiotic. With apparently the same RNA synthesis, more
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ARTEMIA MORPHOGENESIS 267 synthesis (arrows on Fig. 1). The threshold increased with increasing AMP con- centrations. The effect of puromycin, an inhibitor of protein synthesis, also depended on the AMP:CMP ratio of the diet (Fig. 2-5). With a 60 mg % AMP concentration, puromycin action decreased with increasing CMP concentration above the con- centration found necessary for maximum RNA synthesis. Excess CMP did not induce supernumerary gonopodes in the presence of the antibiotic. With apparently the same RNA synthesis, more proteins were synthesized with a reduced AMP:CMP ratio than with a 60:60 ratio (Fig. 4). Similarly, more proteins were synthesized with a reduced ratio than with a 40:40 ratio (Fig. 3). At AMP concentrations of 100 mg %, excess CMP does not induce supernumerary gonopodes (Hernandorena, 1979). In this case, effects of both actinomycin D and puromycin decreased with increasing CMP concentrations (Fig. 5). With a 20 mg % AMP concentration, actinomycin D and puromycin were detrimental. Supernumerary gonopodes were induced provided the medium was not lacking pyrimidines (Hernandorena, 1977). Lack of pyrimidines, which did not decrease RNA synthesis, decreased protein synthesis (Fig. 2). According to these results, the supernumerary gonopodes were induced by in- creased protein synthesis. If this is the case, an albumin deficiency or an albumin excess, which both increase the detrimental effect of puromycin (Hernandorena, 1975) should suppress the induction of supernumerary gonopodes in larvae reared in a medium containing excess cytidylic acid in relation to the adenylic acid con- growth index 13 12 II 10 growth index. 20 40 60 80 CMP mg% 100 120 140 20 40 60 80 100 120 140 CMP mg% FIGURE 2. (Left.) Effect on growth of actinomycin D (2 Mg %) (filled circles) and of puromycin (200 Mg %) (open circles) in relation to the AMP:CMP ratio. AMP constant at 20 mg %. FIGURE 3. (Right.) Effe
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
