. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. X-RAYS AND CYTOPLASMIC INJURY 213 Hatchability studies on 12,634 eggs irradiated in prophase I (Whiting, 1945a) have demonstrated that, when they are not fertilized, (a) the dose-action curve is exponential only at lower doses and that, after higher doses, response increases at a disproportionate rate, (b) lethal dose is about 54,000 r, and (c) hatchability is not changed significantly by varia'tion of intensity of treatment or delay in oviposi- tion but is increased at high doses by fractionation of dose. Prophase I eggs, f
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. X-RAYS AND CYTOPLASMIC INJURY 213 Hatchability studies on 12,634 eggs irradiated in prophase I (Whiting, 1945a) have demonstrated that, when they are not fertilized, (a) the dose-action curve is exponential only at lower doses and that, after higher doses, response increases at a disproportionate rate, (b) lethal dose is about 54,000 r, and (c) hatchability is not changed significantly by varia'tion of intensity of treatment or delay in oviposi- tion but is increased at high doses by fractionation of dose. Prophase I eggs, free from dominant lethal changes after exposures to sub-lethal doses of x-rays, and fertilized by untreated sperm, develop into females. No andro- genetic males have been produced by them. Cytological study of divisions after treatment in this stage has shown (Whiting, 1945b) that fragments, bridges, or both may appear in either meiotic division but that bridges, rarely present in the second meiotic division, are single and do not retard the egg pronucleus. No androgenetic males develop in these eggs, therefore, because of the absence of mechanical hin- drance to free movement of the egg pronucleus. Even after very heavy treatments, eggs often fail to show any chromosome FIGURE 1. Lowest curve, DOSE x androgenetic ?$ , plotted against dose. Remainder are dose-action curves for hatchability of unfertilized prophase I eggs. Continuous treatments (•). two experi- ments ( ) and (— —) ; fractionated treatments (O), (- -). 95 per cent con- fidence interval is indicated for each experimental 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 perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
