Ultrastructure of theDrosophila larval salivary gland cells during the early developmental stages. I. Morphological studies

Early in the third-instar stage of Drosophila auraria, the salivary gland cells produce small secretory granules of low electron density which empty their flocculent contents into the lumen of the gland. At that stage, the Golgi complexes consist of vesiculated, round cisternae which, as middle third instar is approached, change to their classical appearance. Cytoplasmic protrusions, intramitochondrial granules, and close contacts of mitochondria with lipid droplets are observed during the early developmental stages. At about the middle of the third instar the glue secretory granules start being produced. These secretory granules contain a granular material (where small amounts of vicinal glycol and sulfated groups of complex carbohydrates have been detected) of medium electron density. The glue secretory granules can be classified according to their electron density into two populations. Before exocytosis large amounts of glycogen particles are observed, providing some of the energy needed during the final step of exocytosis. Two different types of ribonucleoprotein particles in puffing sites of the chromosomes are observed. Of these, the larger ones consist of a core surrounded by smaller particles; we suspect that they may be produced in the Balbiani rings observed in the polytene chromosomes of this species. Nuclear blebs and oval bodies are common, particularly during the late developmental stages. The functional significance of these findings during development is discussed.

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Review of early developmental stages of trilobites and agnostids from the Barrandian area (Czech Republic)

Journal of the National Museum (Prague), Natural History Series ◽

10.2478/jzh-2018-0006 ◽

2017 ◽

Vol 186 (1) ◽

pp. 103-112

Author(s):

Lukáš Laibl ◽

Oldřich Fatka

Keyword(s):

Czech Republic ◽

Developmental Stages ◽

History Of Research ◽

Early Developmental Stages ◽

History Of ◽

Barrandian Area ◽

Early Developmental

This contribution briefly summarizes the history of research, modes of preservation and stratigraphic distribution of 51 trilobite and five agnostid taxa from the Barrandian area, for which the early developmental stages have been described.

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Stimulation of RNA Synthesis in the Salivary Gland Cells of Sciara Coprophila by an Electromagnetic Signal used for Treatment of Skeletal Problems in Horses

Electromagnetic Biology and Medicine ◽

10.3109/15368378709027727 ◽

1987 ◽

Vol 6 (1) ◽

pp. 37-47

Author(s):

Reba Goodman ◽

Ann Henderson

Keyword(s):

Salivary Gland ◽

Rna Synthesis ◽

Electromagnetic Signal ◽

Gland Cells ◽

Salivary Gland Cells ◽

Stimulation Of

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The Effect of an Anthropogenic Magnetic Field on the Early Developmental Stages of Fishes—A Review

International Journal of Molecular Sciences ◽

10.3390/ijms22031210 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1210

Author(s):

Krzysztof Formicki ◽

Agata Korzelecka-Orkisz ◽

Adam Tański

Keyword(s):

Magnetic Fields ◽

Developmental Stages ◽

Negative Influence ◽

Pigment Cells ◽

Egg Activation ◽

Industrial Equipment ◽

Positive Effects ◽

Early Developmental Stages ◽

Species Specific ◽

Early Developmental

The number of sources of anthropogenic magnetic and electromagnetic fields generated by various underwater facilities, industrial equipment, and transferring devices in aquatic environment is increasing. These have an effect on an array of fish life processes, but especially the early developmental stages. The magnitude of these effects depends on field strength and time of exposure and is species-specific. We review studies on the effect of magnetic fields on the course of embryogenesis, with special reference to survival, the size of the embryos, embryonic motor function, changes in pigment cells, respiration hatching, and directional reactions. We also describe the effect of magnetic fields on sperm motility and egg activation. Magnetic fields can exert positive effects, as in the case of the considerable extension of sperm capability of activation, or have a negative influence in the form of a disturbance in heart rate or developmental instability in inner ear organs.

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