. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 44 G. K. CANTER ET AL. Figure 2. Autoradiography of newly synthesized RNA in lobster gan- glia maintained for 2 and 49 days in vitro. Ganglia were treated with 3H-uridine lor 4 h. followed by a chase with unlabeled medium for 20 h. Following fixation, samples were embedded and sectioned, and autora- diography was performed. The resulting silver grains clustered primarily at the nuclei of cells cultured for 2 and 49 days indicate the presence ol nascent RNA. little difference in grain density between the 2-day and 49-day orga
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 44 G. K. CANTER ET AL. Figure 2. Autoradiography of newly synthesized RNA in lobster gan- glia maintained for 2 and 49 days in vitro. Ganglia were treated with 3H-uridine lor 4 h. followed by a chase with unlabeled medium for 20 h. Following fixation, samples were embedded and sectioned, and autora- diography was performed. The resulting silver grains clustered primarily at the nuclei of cells cultured for 2 and 49 days indicate the presence ol nascent RNA. little difference in grain density between the 2-day and 49-day organ cultures. Similar labeling experiments were performed after other times of incubation with both 3H-uridine and 3H-leucine. In the latter experiments, a cytoplasmic rather than nuclear distribution of silver grains was noted after autoradiogra- phy. indicating the synthesis of protein in the cultured ganglia (data not shown). Cytology of ganglia. Some indication of overall health can be seen in the cytology of cultured ganglia. Cells of ganglia cultured for the longer time period appeared similar to cells of recently dissected ganglia, although the former usually had larger spaces between cells (not shown). Rarely, opaque or darkly colored cells were observed in cultured lobster ganglia, such as those shown in Figure 3 (bottom panel). These cells typically had low or no resting potentials and were likely to be dead or dying. Another feature of unhealthy cells is their slight autofluorescence (Fig. 3, top). The bright cell in Figure 3. top panel, is a GFP-expressing cell. As seen in bright-field illumination (Fig. 3, bottom panel), the GFP-expressing cell is transparent, whereas the two weakly fluorescent cells are opaque. The death of these two cells resulted from experimental DNA injection, de- scribed below. The numbers of spontaneously unhealthy cells was generally low throughout the culture period: most cells and their processes appeared morphologically undis- tinguishable
Size: 1387px × 1801px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
