. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 266 A. HERNANDORENA MATERIALS AND METHODS The method developed by Provasoli and d'Agostino (1969) for axenic culture of the Artemia Utah strain was used. Dietary purine requirement was met by adenylic acid (AMP) and pyrimidine requirement by cytidylic acid (CMP). Al- bumin concentration was 20 mg % unless otherwise stated. The antibiotics used were from Nutritional Biochemical Co. Rearing temperature was 25° ± °, salinity 24%o; 10 ml of medium was used to rear five animals, and 50-100 larvae were reared for each experimen
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 266 A. HERNANDORENA MATERIALS AND METHODS The method developed by Provasoli and d'Agostino (1969) for axenic culture of the Artemia Utah strain was used. Dietary purine requirement was met by adenylic acid (AMP) and pyrimidine requirement by cytidylic acid (CMP). Al- bumin concentration was 20 mg % unless otherwise stated. The antibiotics used were from Nutritional Biochemical Co. Rearing temperature was 25° ± °, salinity 24%o; 10 ml of medium was used to rear five animals, and 50-100 larvae were reared for each experimental conditions. Growth is estimated by a numerical index defined by Provasoli and d'Agostino (1969). This growth index approximates number of molts and size. For graphic comparisons of the experiments, the growth index for the 14th day of development was reported. RESULTS Results are summarized graphically. Figure 1 shows that the effect of acti- nomycin D, an inhibitor of RNA synthesis, decreased with increasing CMP con- centration provided AMP was more than 20 mg %. RNA synthesis was not limited by CMP with a 20 mg % AMP concentration. RNA synthesis was limited by CMP concentrations of 0-40 mg % with a 40 mg % AMP concentration, of 0-60 mg % with a 60 mg % AMP concentration, of 0-100 mg % with a 100 mg % AMP concentration. The CMP concentrations inducing supernumerary gonopodes are exactly those found to exceed the minimum CMP requirement for maximum RNA growth index. 20 40 60 80 TOO CMP mg % 120 140 FIGURE 1. Effect on growth of actinomycin D (2 ^g %) rn relation to the AMPrCMP ratio. Open triangles = AMP: 20 mg %; Open circles = AMP: 40 mg %. Filled circles = AMP: 60 mg %; Filled triangles = AMP: 100 mg %. The arrows indicate minimum CMP concentrations inducing supernumerary Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfe
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
