. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ACTIVATION OF THE PROTHORACIC GLAND 509. FIGURE 12. A, Microvilli found in the peripheral membrane of the prothoracic glands; B, release of the secretory substances from the microvilli by pinching off tips of microvilli. Dark material to the right of B is made up of condensed secretory substances; scale /*. of RNA synthesis occurred at the time when the prothoracic gland-cell nuclei were regular in shape. By the time the maximum rate of RNA synthesis was reached, nuclear folding and vacuolization were evident. The incorp
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ACTIVATION OF THE PROTHORACIC GLAND 509. FIGURE 12. A, Microvilli found in the peripheral membrane of the prothoracic glands; B, release of the secretory substances from the microvilli by pinching off tips of microvilli. Dark material to the right of B is made up of condensed secretory substances; scale /*. of RNA synthesis occurred at the time when the prothoracic gland-cell nuclei were regular in shape. By the time the maximum rate of RNA synthesis was reached, nuclear folding and vacuolization were evident. The incorporation was found first in the nucleus (Fig. 13) and then in the cytoplasm (Fig. 14). The correlation between RNA synthesis and the cytological changes during secretion described above was most striking. The increase of uridine incorporation was closely cor- related with the appearance of secretory activity in the gland cells. It seems ap- parent that a close interaction between the nucleus and the cytoplasm is necessary for the synthesis of the secretory substances. Ecdysone biosynthesis in the prothoracic glands Detection of cholesterol in the prothoracic glands. Cholesterol has been demon- strated to be the precursor of ecdysone in Calliphora erythrocephara (Karlson and Hoffmeister, 1963; Willig et al., 1971), Calliphora stygia (Galbraith et al, 1970), Bombyx mori (Moriyama et al., 1970; Nakanishi et al., 1972), Mamestra brassicae. 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, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-1983. Woods Hole, Mass. : Marine Biological Laboratory
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
