. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. HEMATOPOIESIS AND MOLTING IN DECAPODS 191. Figure 2. Transmission electron micrographs and lighl micrographs (inserts) of dividing cells. Spindle microtuhules and centrioles are not visible in the electron micrographs, hut both cells lack nuclear envelopes. (A) Granulocyte stem cell in metaphase; insert shows a cell in anaphase (arrows = granules). (B) Hyaline cell in prophase or metaphase. Right insert shows a cell in telophase and left insert same cell at a higher magnification (*) of a typical granule with a striate
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. HEMATOPOIESIS AND MOLTING IN DECAPODS 191. Figure 2. Transmission electron micrographs and lighl micrographs (inserts) of dividing cells. Spindle microtuhules and centrioles are not visible in the electron micrographs, hut both cells lack nuclear envelopes. (A) Granulocyte stem cell in metaphase; insert shows a cell in anaphase (arrows = granules). (B) Hyaline cell in prophase or metaphase. Right insert shows a cell in telophase and left insert same cell at a higher magnification (*) of a typical granule with a striated substructure from the hyaline cell. Granulocyte and hyaline stem cells may be distinguished by differences in the electron density of the cytoplasm (note the darker cytoplasm of the hyaline cell) and the substructure of the cytoplasmic granules (arrows). Note the homogeneous substructure of the electron dense granules in the granulocyte stem cell. Electron micrographs 9600- ; scale bar = 5 ^m. Light micrographs—methylene blue. 1800x. ocytes constituted only 12-20% of the total hematopoietic cells during these stages. After molting, the number of hemocytes almost tripled to 42. Throughout the post-ec- dysial stages (A, to B), their numbers doubled as maturing hemocytes accumulated within the tubules. In stage B, 48% of the hematopoietic cells were hemocytes. Cells of the granulocyte line predominated within the intermolt and early pre molt hematopoietic tissue (stages C through D,_:). Mitotic activity progressively increased from stage A, to a peak at stage D0. Numbers of granu- locyte stem cells were lowest during stage C, and increased to a maximum during stage D3_4 (Fig. 3). During stages B and C, granulocyte stem cells were usually the earliest forms with zero or only a few coalescing granules and a distinctive large central nucleolus. Stem cells in stage C tubules were the largest of any molt stage, averaging /jm in diameter (Table I). More mature, smaller stem cell
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
