An unknown nucleus in the lateral loop of the dophin brain, its morphological organization and origin

1978 ◽  
Vol 9 (2) ◽  
pp. 142-145
Author(s):  
V. P. Zvorykin
Keyword(s):  
Morphological Organization ◽  
Lateral Loop

Cytoplasmic Organization in the Receptor Cells of the Crista Ampullaris

1972 ◽  
Vol 30 ◽  
pp. 60-61 ◽  
Author(s):  
Robert F. Dunn
Keyword(s):  
Fine Particles ◽  
Apical Cell ◽  
Apical Region ◽  
Receptor Cells ◽  
Cuticular Plate ◽  
Morphological Organization ◽  
Crista Ampullaris ◽  
Cytoplasmic Organization ◽  
High Degree ◽  
General Appearance

Receptor cells of the cristae in the vestibular labyrinth of the bullfrog, Rana catesbiana, show a high degree of morphological organization. Four specialized regions may be distinguished: the apical region, the supranuclear region, the paranuclear region, and the basilar region.The apical region includes a single kinocilium, approximately 40 stereocilia, and many small microvilli all projecting from the apical cell surface into the lumen of the ampulla. A cuticular plate, located at the base of the stereocilia, contains filamentous attachments of the stereocilia, and has the general appearance of a homogeneous aggregation of fine particles (Fig. 1). An accumulation of mitochondria is located within the cytoplasm basal to the cuticular plate.

FEATURES OF FORMATION OF THE MAIN SYSTEMS AND ORGANS IN EARLY LARVAE OF MULLETS (LIZA AURATA, RISSO, 1810)

2017 ◽  
pp. 98-106
Author(s):  
Dariya Aleksandrovna Gavrilova ◽  
Maria Pavlovna Grushko
Keyword(s):  
Nervous System ◽  
Sample Selection ◽  
Early Ontogeny ◽  
Basal Cells ◽  
The Caspian Sea ◽  
Liza Aurata ◽  
Morphological Organization ◽  
Organ Systems ◽  
Major Organ ◽  
Well Differentiated

The aim of this work was to study peculiarities of mullet morphological organization during early ontogeny. Sample selection was made on board Caspian research and development Institute of Fisheries’ research vessel in period from June to September, 2015 in Russian waters of the Caspian Sea. Larvae aged 10 days could be characterized by heterochrony in the development of major organ systems. Nervous system and sense organs were well developed. The eyeball had all membranes well-differentiated, in the retina all the layers were formed. The olfactory fossae had cells of 3 types: olfactory receptor cells, supporting cells and basal cells. There was observed intensive formation of respiratory, cardiovascular, excretory and digestive systems. The early development of the nervous system and sensory organs of the larvae indicated adaptation of mullet to active life.

Venom gland morphology in Pepsis pallidolimbata pallidolimbata and biological use and activity of Pepsis venom

1997 ◽  
Vol 75 (7) ◽  
pp. 1014-1019 ◽  
Author(s):  
E. Schoeters ◽  
J. Billen ◽  
J. O. Schmidt
Keyword(s):  
Venom Gland ◽  
Social Wasps ◽  
Morphological Organization ◽  
The Social ◽  
The Family ◽  
Venom Glands ◽  
Glandular Structures ◽  
Sibling Family

Spider wasps, i.e., the family Pompilidae, in general, and those belonging to the genus Pepsis in particular, are acknowledged to possess venoms that are algogenic to humans and thus have the parsimonious functions of causing paralysis and providing defense against predators. The morphological organization of the venom system and its complex convoluted gland closely resembles that in social members of the Vespidae. These features distinguish the venom glands of the Pompilidae from those of the sibling family Mutillidae as well as those of the family Sphecidae, which lack convoluted glands. Although the venom glands in Pepsis species are very similar in morphology to those of social vespids, the lethality of Pepsis venom to mammals is several times less than that of the social common wasps. These findings suggest that in terms of the evolution of venom activity and the associated glandular structures, there was apparently no need for social wasps to develop extra parts of the venom system for producing toxic, lethal, or powerful algogenic components. All of the glandular parts of the venom gland of social wasps were already present in pompilids (and eumenids) and, presumably, in their ancestors.

Carboxylesterase overexpression in the male reproductive tract: a universal safeguarding mechanism?

1999 ◽  
Vol 11 (3) ◽  
pp. 133 ◽  
Author(s):  
A. T. Mikhailov ◽  
M. Torrado
Keyword(s):  
Reproductive Tract ◽  
Expression Patterns ◽  
Cell Lineage ◽  
Environmental Chemicals ◽  
Male Reproductive Tract ◽  
Morphological Organization ◽  
Associated Functions ◽  
And Function ◽  
Hypothetical Explanation

Data on expression patterns of carboxylesterases in the male reproductive tract of different animal groups (i.e. bivalve mollusks, fruitflies and rodents) are summarized to highlight some particularly interesting questions in the context of sperm differentiation, maturation and function. The male reproduc-tive system, in spite of extreme variation in the anatomical/morphological organization in different species, is characterized by similar patterns of male-dependent carboxylesterase overexpression. The phenomenon of conserved carboxylesterase overexpression indicates similar male sex-associated functions of the enzymes. There is possible evidence of carboxylesterase recruitment by male reproductive-tract tissues indi-cating that it could be adaptive for spermatogenesis, sperm maturation and sperm use. Moreover, this idea can be extended to include a sperm cell lineage protection. This issue is discussed in the light of recent data on environmental reproductive xenobiotics that can provide a basis for a hypothetical explanation of car-boxylesterase overexpression in the male reproductive tract. Based on a well-known role of car-boxylesterases in detoxification of environmental chemicals such as organophosphate pesticides, it is proposed that various male genital tract carboxylesterases may be characterized by a similar physiological function to protect the male reproductive system against xenobiotic influences that could provoke its dys-function, thus altering sperm differentiation and maturation.

scholarly journals Morphological diversity of fish along the rio das Velhas, Minas Gerais, Brazil

2012 ◽  
Vol 10 (2) ◽  
pp. 417-424 ◽  
Author(s):  
Nara Tadini Junqueira ◽  
Cecília Gontijo Leal ◽  
Carlos Bernardo Mascarenhas Alves ◽  
Paulo Santos Pompeu
Keyword(s):  
Fish Assemblages ◽  
Morphological Diversity ◽  
Minas Gerais ◽  
Two Dimensions ◽  
Anthropogenic Pressures ◽  
Morphological Attributes ◽  
Morphological Organization ◽  
Minas Gerais State ◽  
Major Tributary ◽  
Euclidean Distances

The rio das Velhas, located in central Minas Gerais State (Brazil), is a major tributary of the rio São Francisco. Despite several anthropogenic pressures, this basin supports more than 115 fish species. The aim of this study was to compare the morphological space occupied by fish assemblages in four regions (headwaters, upper, middle, and lower course) along the channel of the rio das Velhas. We try to answer the following question: Is there a change in the morphological organization of the fish along the longitudinal gradient of the river? Individuals from 67 species, collected at several sites in the basin from 1999 to 2008, were measured for 11 morphological attributes related to swimming behavior and habitat use. Through the graphs, the first two dimensions of the PCA suggest that the morphological volume occupied by the headwaters region is smaller than the other sections, because of the low richness of the site. However, morphological hypervolumes of the four reaches analyzed by Euclidean distances were not statistically different. The results indicated that only the density of morphological types increases along the rio das Velhas, and there is no difference between the headwaters and upper courses. Therefore, in order to use functional groups related to the morphology of the species as tools to take measures for the conservation and revitalization of the rio das Velhas, it is necessary analyze the density of species within these groups, as well as their composition.

Development of the iris in the chicken embryo

Development ◽  
1984 ◽  
Vol 81 (1) ◽  
pp. 169-183
Author(s):  
Patricia A. Ferrari ◽  
William E. Koch
Keyword(s):  
Epithelial Cells ◽  
Chicken Embryo ◽  
Muscle Differentiation ◽  
Muscle Fibres ◽  
Tissue Interactions ◽  
Morphological Organization ◽  
Chicken Muscle ◽  
Muscle Myosin

The developmental capabilities of the iris rudiment in the chicken embryo, as well as the role of tissue interactions in the differentiation of the iris, were investigated in vitro. Sectors of the intact iris from 7½- through 9-day embryos (stages 32 through 35) lost their morphological organization in vitro, but were capable of normal histodifferentiation. The pigmentation of the epithelium increased, and muscle differentiation occurred. Developing muscle was identified using immunocytochemistry with antiserum against chicken muscle myosin; this procedure permitted positive identification of myoblasts, myotubes, and muscle fibres in cultures in which histological features alone were equivocal. The proportion of irideal explants which developed muscle increased with the age of the embryo, and correlated with the incidence of epithelial buds and epithelial cells in the stroma. Irideal mesenchyme from stage-32 through stage-35 embryos was already populated with stromal epithelial cells when isolated, but growth and muscle differentiation in these cultures compared poorly with that in the intact iris in vitro. Isolated irideal epithelium (stages 32 through 37) demonstrated even more limited muscle differentiation in vitro, suggesting reciprocal interaction between irideal epithelium and mesenchyme during development. Irideal epithelium was also cultured in direct association with non-irideal mesenchyme from various embryonic organ rudiments, but muscle differentiation was not enhanced.

The Actions of Enzymes on Lampbrush Chromosomes

1962 ◽  
Vol s3-103 (62) ◽  
pp. 173-203
Author(s):  
H. C. MACGREGOR ◽  
H. G. CALLAN
Keyword(s):  
Proteolytic Enzymes ◽  
Lampbrush Chromosomes ◽  
Triturus Cristatus ◽  
Trichloracetic Acid ◽  
Protease Digestion ◽  
Lateral Loop ◽  
Peptic Digestion ◽  
Rnase Digestion ◽  
Break Chromosome ◽  
Loop Matrix

The chromomeres of lampbrush chromosomes of Triturus cristatus are Feulgen-positive; they therefore contain DNA. After removal of their DNA in boiling trichloracetic acid, the chromomeres stain with fast green at alkaline pH; they therefore contain basic protein. The lateral loops are Feulgen-negative; they stain with toluidine blue at acid pH, but much less intensely following RNase digestion; they therefore contain RNA. The spheres of chromosomes V and VIII do not contain RNA. Unfixed lampbrush chromosomes retain a life-like appearance in 0.07 M K/NaCl at pH 6.2; in this medium the nuclear sap disperses. As pH is raised to 8.5 the matrices of lateral loops dissolve but chromosome axes remain unbroken. Above pH 8.5 lampbrush chromosomes dissolve. As pH is lowered from 6.2, at between 5.8 and 5.4 coagulation occurs. If pH is rapidly reduced still further, a persistent relaxed condition sets in between 2.5 and 2. In concentrations of K/NaCl above 0.5 M lampbrush chromosomes dissolve. Lateral loop matrices dissolve in 0.25 M K/NaCl but chromosome axes remain unbroken. In concentrations of K/NaCl below 0.05 M lateral loop matrices dissolve, but even in distilled water chromosome axes remain unbroken. Trypsin at pH 6.2 and at pH 7.8 strips the matrices from lateral loops and occasionally breaks matrix fusions. It causes chromomeres to swell and coalesce, but fails to break chromosome axes. The action of ‘pan-protease’ resembles that of trypsin in all respects. Pepsin at pH 6.2 strips the matrices from lateral loops, but does not destroy chromomeres. At low pH peptic digestion is slow: the enzyme is attacking coagulated chromosomes; but if peptic digestion precedes a lowering of pH the overall outcome is a rapid solution of loop matrix, and under these conditions matrix and sphere fusions are broken. If trypsin or ‘pan-protease’ digestion precedes a lowering of pH there is a similarly rapid solution of loop matrix; thus the action is not specifically referable to pepsin. Under no conditions does pepsin break the axes of lampbrush chromosomes. RNase at pH 6.2 strips the matrices from lateral loops; this action is detectable at extreme dilution. RNase does not destroy chromomeres, nor does it break chromosome axes. If tryptic digestion follows RNase digestion this too fails to break chromosome axes. Unlike the proteolytic enzymes and RNase, DNase at pH 6.2 breaks the fibril between adjacent chromomeres, and it also breaks the axes of lateral loops. Contrary to Mazia's experience with salivary gland chromosomes, versene does not break the axes of lampbrush chromosomes even when applied in media of low electrolyte concentration. These results indicate that uninterrupted fibres of DNA run throughout the lengths of lampbrush chromosomes.

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