The Fate of the Kolk Syncytial Layer during Postembryonic Development of Stenodus leucichthys nelma

The simplicity of the developing nervous system of oligochaetes makes of it an excellent model for the study of the relationships between glia and neurons. In the present communication we describe the relationships between glia and neurons in the early periods of post-embryonic development in some species of oligochaetes.Tubifex tubifex (Mull. ) and Octolasium complanatum (Dugès) specimens starting from 0. 3 mm of body length were collected from laboratory cultures divided into three groups each group fixed separately by one of the following methods: (a) 4% glutaraldehyde and 1% acrolein fixation followed by osmium tetroxide, (b) TAPO technique, (c) ruthenium red method.Our observations concern the early period of the postembryonic development of the nervous system in oligochaetes. During this period neurons occupy fixed positions in the body the only observable change being the increase in volume of their perikaryons. Perikaryons of glial cells were located at some distance from neurons. Long cytoplasmic processes of glial cells tended to approach the neurons. The superimposed contours of glial cell processes designed from electron micrographs, taken at the same magnification, typical for five successive growth stages of the nervous system of Octolasium complanatum are shown in Fig. 1. Neuron is designed symbolically to facilitate the understanding of the kinetics of the growth process.

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Embryonic and Early Postembryonic Development of Carp and Activity of Enzymes of the Energy and Plastic Metabolism under Impact of Water Temperature Fluctuations

Hydrobiological Journal ◽

10.1615/hydrobj.v53.i1.80 ◽

2017 ◽

Vol 53 (1) ◽

pp. 78-86

Author(s):

O. M. Vodianitskiy ◽

O. S. Potrokhov ◽

O. G. Zinkovskiy

Keyword(s):

Water Temperature ◽

Temperature Fluctuations ◽

Postembryonic Development ◽

Plastic Metabolism ◽

Activity Of Enzymes

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Distribution of the cestode Urocystis prolifer Villot, 1880 (Cyclophyllidea: Hymenolepididae) in the Palaearctic and new data on its postembryonic development

Journal of Helminthology ◽

10.1017/s0022149x21000249 ◽

2021 ◽

Vol 95 ◽

Author(s):

S.A. Kornienko ◽

L.A. Ishigenova

Keyword(s):

Host Specificity ◽

Geographical Distribution ◽

Experimental Infection ◽

Definitive Host ◽

Intestinal Parasite ◽

Geographic Area ◽

Postembryonic Development ◽

Generic Diagnosis ◽

Intermediate Hosts ◽

Very High

Abstract Urocystis prolifer Villot, 1880 is an intestinal parasite of Sorex spp. In the Palaearctic. There are significant differences in the descriptions of both adults and stages of ontogenesis of U. prolifer as described by various authors. The experimental infection of intermediate hosts with cestodes has been conducted. An overview of the geographical distribution, infestation of the definitive hosts and the development of the metacestode stages of U. prolifer are presented. The cestode is characterized by an extensive geographic area in the Palaearctic, wide host specificity and very high rates of infection of its definitive host. Urocystis prolifer has been recorded mostly in the taiga and forest zones of Palaearctic. Fourteen species of Sorex were registered as the definitive host. Redescription of U. prolifer and an amended generic diagnosis are provided. A complete description of the ontogeny from oncosphere to fully developed metacestode is given. Features of development of the metacestode are an asexual larval reproduction, the absence of the anterior and posterior obturator valve in the cyst of the fully developed urocyst, as well as excretory bodies.

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Molecular cloning and analysis of l(1)ogre, a locus of Drosophila melanogaster with prominent effects on the postembryonic development of the central nervous system.

Genetics ◽

10.1093/genetics/126.4.1033 ◽

1990 ◽

Vol 126 (4) ◽

pp. 1033-1044 ◽

Cited By ~ 2

Author(s):

T Watanabe ◽

D R Kankel

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Postembryonic Development ◽

P Element ◽

Reading Frame ◽

Isolation And Characterization ◽

The Central Nervous System ◽

Highly Hydrophobic ◽

Conceptual Translation

Abstract Previous genetic studies have shown that wild-type function of the l(1)ogre (lethal (1) optic ganglion reduced) locus is essential for the generation and/or maintenance of the postembryonic neuroblasts including those from which the optic lobe is descended. In the present study molecular isolation and characterization of the l(1)ogre locus was carried out to study the structure and expression of this gene in order to gain information about the nature of l(1)ogre function and its relevance to the development of the central nervous system. About 70 kilobases (kb) of genomic DNA were isolated that spanned the region where l(1)ogre was known to reside. Southern analysis of a l(1)ogre mutation and subsequent P element-mediated DNA transformation mapped the l(1)ogre+ function within a genomic fragment of 12.5 kb. Northern analyses showed that a 2.9-kb message transcribed from this 12.5-kb region represented l(1)ogre. A 2.15-kb portion of a corresponding cDNA clone was sequenced. An open reading frame (ORF) of 1,086 base paris was found, and a protein sequence of 362 amino acids with one highly hydrophobic segment was deduced from conceptual translation of this ORF.

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