. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DMA SYNTHESIS IN REGENERATION 327 blastema (Ax) fractions. The non-regenerating areas near the head hlastemata had higher activities than similar areas near the tail blastemata (P2 > A,). The great- est amount of C14O2 incorporation into DNA occurred at 4 hours for the tail blastemata (AJ and the adjacent area (A2), while the incorporation of label into both DNA and RNA of all the other fractions was greatest at 6 hours. In com- paring the levels of isotope incorporation of the worms allowed to regenerate two hours in unl
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DMA SYNTHESIS IN REGENERATION 327 blastema (Ax) fractions. The non-regenerating areas near the head hlastemata had higher activities than similar areas near the tail blastemata (P2 > A,). The great- est amount of C14O2 incorporation into DNA occurred at 4 hours for the tail blastemata (AJ and the adjacent area (A2), while the incorporation of label into both DNA and RNA of all the other fractions was greatest at 6 hours. In com- paring the levels of isotope incorporation of the worms allowed to regenerate two hours in unlabeled medium and three hours in C14O, with those in which the worms regenerated four or six hours in unlabeled medium and three hours in C14(X sig- nificant increases of incorporation of labeled precursor into DNA and RNA were observed in the four- and six-hour experiments. Furthermore, there is a marked stimulation of DNA synthesis in the blastemata of worms that regenerated four hours in unlabeled medium, but no further significant stimulation of labeled pre- cursor into DNA after six hours of regeneration in unlabeled medium. The extent of stimulation of RNA synthesis, particularly in the anterior pieces (P1 and P2), was greater between four and six hours of regeneration in unlabeled medium, as compared to the difference between two and four hours of regeneration in the un- labeled medium. The specific activities of the protein fraction were maximal after 24 hours of regeneration in tap water and three hours with the label. The differ- ences in isotopic activities of the protein fraction between the head and tail blastemata. FIGURE 1. For each experiment 100 worms were cut at level x and allowed to regenerate for 2, 4, 6 and 24 hours. The blastemata (A! and Pi) and adjacent areas (A« and P->) were cut and then incubated separately for three hours in 1 ml. of boiled tap water containing C14O2 generated from 150 /*c. of BaC14O::.. Please note that these images are extract
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
