ISSN:
1432-0878
Keywords:
Midgut epithelium
;
Calliphora erythrocephala
;
(Insect)
;
Diptera
;
Embryogenesis
;
Electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Ultrastructural changes in midgut epithelial cells of Calliphora during the last nine hours of development are described on the basis of a division into four stages. The midgut differentiates into three parts, the anterior midgut part (AMP), the mid-midgut part (MMP), and the posterior midgut part (PMP). The ultrastructure and the developmental changes in it are practically the same in AMP and PMP cells, but the MMP cells show a different pattern. The lateral membrane junctions are more extensive in the MMP than in the AMP and PMP, but the brush-border of MMP cells is less developed. Variations in the number, size, and electron density of vesicles presumably derived from Golgi regions are larger in this part of the midgut than in other parts. Mitochondrial length increases in all three parts of the midgut, as do the nuclear and nucleolar diameters, attended by an increase in the amount of RER. Two other types of cell are found very sporadically in the midgut epithelium, i.e. presumptive larval granular and presumptive imaginal midgut cells. The yolk mass lying in the midgut lumen is considered to be a very active system that can perform many cellular processes. There are important differences in the ultrastructural development of embryonic and pupal midgut epithelial cells, especially in the formation of the brush-border, the elimination of mitochondria, and the storage and consumption of glycogen.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00306689
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