An ultrastructural and histochemical study of the secretory granules in the salivary gland cells of the Drosophila melanogaster species subgroup: phylogenetic relationships and evolutionary aspects

1987 ◽  
Vol 65 (4) ◽  
pp. 950-957 ◽  
Author(s):  
G. N. Thomopoulos
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Gland ◽  
Granular Material ◽  
Secretory Granules ◽  
Ultrastructural Level ◽  
Structural Level ◽  
Gland Cells ◽  
Salivary Gland Cells ◽  
Complex Carbohydrates ◽  
Filamentous Material

The morphology of the secretory granules and the distribution of "neutral" complex carbohydrates in these structures of the larval salivary gland cells of six species belonging to the melanogaster subgroup of Drosophila were examined at the ultra-structural level. The secretory granules of each species show a unique morphology. The species of the melanogaster subgroup can be subdivided into two complexes (the melanogaster and the yakuba complexes) on the basis of the existence of filamentous or granular material in their secretory granules. In the former complex belong the species Drosophila melanogaster, Drosophila simulans, and Drosophila mauritiana, whose secretory granules consist mainly of filamentous material, and in the latter complex belong the species Drosophila yakuba, Drosophila teissieri, and Drosophila erecta, whose secretory granules consist of granular material. A phylogeny of the six species, in which D. erecta is regarded as the most primitive, is presented. It is proposed that the morphology of the secretory granules at the ultrastructural level, combined with the distribution of complex carbohydrates in them, can be used as an additional criterion for the classification of the Drosophila species.

Structural and histochemical studies of Golgi complex differentiation in salivary gland cells during Drosophila development

1992 ◽  
Vol 102 (1) ◽  
pp. 169-184 ◽  
Author(s):  
G.N. Thomopoulos ◽  
E.P. Neophytou ◽  
M. Alexiou ◽  
A. Vadolas ◽  
S. Limberi-Thomopoulos ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Golgi Complex ◽  
Secretory Granules ◽  
Differential Staining ◽  
Reaction Products ◽  
Trans Golgi Network ◽  
Gland Cells ◽  
Salivary Gland Cells ◽  
Complex Carbohydrates ◽  
Golgi Network

Morphological alterations in the Golgi complex (GC) and changes in the distribution of acid phosphatase (AcPase), thiamine pyrophosphatase (TPPase), complex carbohydrates and reduced osmium tetroxide compounds in this organelle were studied in the salivary gland cells of Drosophila during larval and prepupal development. The morphology and the AcPase, TPPase and complex carbohydrates cytochemical patterns of the Golgi complex varied characteristically during cell differentiation. At the early 3rd instar period the Golgi complex consisted mainly of vesiculated cisternae, and AcPase activity was observed in all cisternae but not in the secretory granules. As development proceeded to the late 3rd instar the Golgi complex displayed its typical appearance, consisting of four to six cisternae, and only the two to three cisternae towards the trans-face as well as the trans-Golgi network and some of the immature secretory granules exhibited AcPase reactivity. In the course of a ‘wave’ of production of the ‘glue’ secretory granules proceeding proximally through the gland, the number of AcPase positive cisternae changed correspondingly. After secretion of the ‘glue’ secretory granules, the size of the Golgi complex decreased and almost all cisternae displayed AcPase reactivity. The detection of TPPase activity presented some specificity problems, since staining was observed not only in the GC cisternae but in the endoplasmic reticulum (ER) and microvilli. The reaction products were seen in a few GC vesicles during the early 3rd instar and in the trans side of the organelle at the end of the 3rd instar. During production of the secretory granules, every GC cisterna was intensely stained. These results agree with previous findings suggesting that AcPase and TPPase in secretory cells may be primarily involved in the processing of exportable proteins. The vicinal (vic)-glycol groups of the complex carbohydrates were detected using the periodic acid/thiocarbohydrazide/silver proteinate (PA-TCH-SP) technique. During synthesis of the ‘glue’ secretory granules, the reaction products were observed over the GC cisternae and the trans-Golgi network, with increasing intensity from the cis to the trans side of the organelle. No PA-TCH-SP staining was observed over the GC cisternae during the early 3rd instar. Following discharge of the ‘glue’ secretory granules, all GC cisternae displayed uniform PA-TCH-SP staining. After OsO4 impregnation, the reaction products were observed mainly in ER and mitochondria and rarely in the GC. In numerous cells, only the mitochondria were stained, while in many cases the ER of neighboring cells exhibited differential staining.(ABSTRACT TRUNCATED AT 400 WORDS)

WHOLE MOUNT ELECTRON MICROSCOPY OF THE NUCLEOLUS IN SALIVARY GLAND CELLS OF DROSOPHILA MELANOGASTER

1977 ◽  
Vol 19 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Gary D. Burkholder
Keyword(s):  
Electron Microscopy ◽  
Drosophila Melanogaster ◽  
Salivary Gland ◽  
Peripheral Region ◽  
Core Region ◽  
28S Rrna ◽  
The Core ◽  
Gland Cells ◽  
Salivary Gland Cells ◽  
Whole Mount

The nucleolus of Drosophila melanogaster salivary gland cells, examined by whole mount electron microscopy, consists of a fibrillar core region and a peripheral region containing both fibres and granules. These regions appear to correspond to the fibrillar and granular components, respectively, seen in thin sections. Most of the nucleoli were attached to the chromocenter region of the polytene chromosomes, containing the nucleolar organizer. Bundles of relatively straight chromatin fibres, 13 nm in diameter, extended from the chromocenter into the core region of the nucleolus, however it was not possible to trace the path of these chromatin fibres through the nucleolus since they were obscured within the mass of nucleolar fibres. The nucleolar fibres in both the core and peripheral regions were irregular and knobby, with a diameter of about 15 nm. In the core region, the fibres appeared to be of considerable length and were characteristically clustered together to form small interconnected masses. The fibres in the peripheral region were relatively short and some appeared to blend with amorphous, poorly-defined pools of material. Electron dense granules 15-20 nm in diameter were also associated with this amorphous substance. It is hypothesized that the formation and subsequent packaging of the 28s rRNA may be represented by a morphological transition of the peripheral fibres, via an amorphous pool-like intermediate stage, into the nucleolar granules. The results of this study indicate that whole mount electron microscopy may be a useful alternative to thin sectioning in high resolution studies of the nucleolus.

scholarly journals CHROMOSOME-NUCLEAR MEMBRANE-CYTOPLASMIC INTERRELATIONS IN DROSOPHILA

1956 ◽  
Vol 2 (4) ◽  
pp. 407-414 ◽  
Author(s):  
Helen Gay
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Gland ◽  
Larval Development ◽  
Electron Micrographs ◽  
Nuclear Membrane ◽  
Membrane Structure ◽  
Deoxyribonucleic Acid ◽  
Cellular Function ◽  
Gland Cells ◽  
Salivary Gland Cells

The structural evidence for nucleocytoplasmic interrelationships observed in electron micrographs of salivary-gland cells of third instar larvae of Drosophila melanogaster has been reviewed. It has been found that the characteristic nuclear membrane outpocketings with their adjacent highly differentiated chromosomal materials occur at one stage of larval development at a time when a new cellular function is being initiated. Preliminary cytochemical studies to characterize the materials transferred from nucleus to cytoplasm indicate that deoxyribonucleic acid occurs within the blebs. Observations on chromosome and nuclear membrane structure are also presented.

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