Biphasic moult cycle of the parasitic isopod Norileca indica (H. Milne Edwards, 1840) (Isopoda: Cymothoidea): stage-wise characterisation and haemolymph ecdysteroids titre

2019 ◽  
Author(s):  
Amrutha Vani Sahadevan ◽  
T A Jose Priya ◽  
Sudha Kappalli
Keyword(s):  
Anterior Part ◽  
Adult Population ◽  
Posterior Part ◽  
Maximum Level ◽  
Body Part ◽  
Body Region ◽  
Moult Cycle ◽  
Parasitic Isopods ◽  
Anterior Body ◽  
Parasitic Isopod

Abstract Norileca indica (H. Milne Edwards, 1840) is a protandrous hermaphroditic and obligatory parasitic isopod of scombrid fishes. The posterior and anterior biphasic moult cycles in the adult phases (male, transitional, and female) of this species are characterised based on the microscopic changes reflected in the uropod exopodite and maxillule, respectively. Biphasic parturial moult as well as the moult removing the old brood pouch characteristic of ovigerous females was recorded. Assay of haemolymph ecdysteroids titre with respect to different biphasic moult cycle stages appears to be first report of its kind among aquatic and/or parasitic isopods. The ecdysteroids titre showed significant fluctuation in relation to the moult cycle stages, while the parasite was at a biphasically intermoult stage, titre was estimated to be 13.64 ± 2.09 ng ml–1. By the onset of the premoult at the posterior body region, titre showed a gradual increase and reached a maximum level (328.54 ± 70.17 ng ml–1; P = 0.0060) when the parasite was at late premoult at the posterior body part and mid premoult stage at the anterior body part. There was a subsequent sharp decline (92.8 ± 12.95 ng ml–1; P = 0.002) soon after the ecdysis of the posterior part by the time premoult changes in the anterior part advanced as late premoult and about to moult. The level of ecdysteroids titre was 55.56 ± 14.47 ng ml–1 when the parasite completed anterior ecdysis and reached postmoult. Data on the monthly occurrence of biphasic moult cycles revealed that a mean average of 23.26% of the adult population undergoes premoult/ecdysis/postmoult activities throughout the year. The rate of moulting showed a decline (16.12 ± 0.60%) during the monsoon months (June-August) when compared to pre-summer/summer (February-May) (24.83 ± 2.42%) and post-monsoon/winter (September-January) (26.28 ± 1.75; P = 0.005).

scholarly journals Histological and Morphometrical Study of the Filiform Papillae in the Domestic Rabbit (Oryctolagus cuniculus)

2021 ◽  
Vol 78 (1) ◽  
pp. 63
Author(s):  
Mircea CIPOU ◽  
Cristian MARTONOS ◽  
Adrian Florin GAL ◽  
Vasile RUS ◽  
Ion VLASIUC ◽  
...  
Keyword(s):  
Anterior Part ◽  
Posterior Part ◽  
Dorsal Surface ◽  
Maximum Level ◽  
Body Part ◽  
The Body ◽  
Domestic Rabbit ◽  
Mixed Breed ◽  
Filiform Papillae ◽  
Morphometrical Study

The domestic rabbit is often preferred as an experimental model in diverse research and especially those regarding pathologies of the oral cavity, both in human and veterinary medicine. From five domestic mixed breed rabbits, fragments were harvested from the three regions of the tongue: apex, body and root, for histological investigations. The samples were processed by embedding in paraffin, sectioned at a thickness of 5 µm and stained with Goldner’s trichrome method. The histological examination highlighted the presence of the filiform papillae on the entire dorsal surface of the tongue, with morphological particular carachteristics for each portion. The dimension of the filiform papillae of the rabbit’s tongue differs both regarding the length as well as the thickness and density. The shortest filiform papillae were found on the tip of the tongue, then the length increases progressively, reaching the maximum level on the middle portion and decreases in the last portion. The density also differs, in in the three compartments examined, being the highest in the anterior part and the lowest in the posterior part. The thickness of the filiform papillae is inversely proportional to their density. The thickness of the papillae is smaller where the density is higher and highest where the density is lowest. The upper surface of the filiform papillae is variably keratinized depending on the lingual segment. The papillae with the highest level of keratinization are arranged in the body part of the tongue, and those at the tip and root are slightly lower.

Fine structure of the rectal papillae of the oriental fruuit fly, Dacus dorsalis Hendel (Tephritidae, Diptera Insecta)

1990 ◽  
Vol 48 (3) ◽  
pp. 498-499
Author(s):  
Len Wen-Yung ◽  
Mei-Jung Lin
Keyword(s):  
Fine Structure ◽  
Cell Membrane ◽  
Intercellular Space ◽  
Anterior Part ◽  
Apical Cell ◽  
Posterior Part ◽  
Apical Cell Membrane ◽  
Dacus Dorsalis ◽  
Radial Cell ◽  
Circular Base

Four cone-shaped rectal papillae locate at the anterior part of the rectum in Dacus dorsalis fly. The circular base of the papilla protrudes into the haemolymph (Fig. 1,2) and the rest cone-shaped tip (Fig. 2) inserts in the rectal lumen. The base is surrounded with the cuticle (Fig. 5). The internal structure of the rectal papilla (Fig. 3) comprises of the cortex with the columnar epithelial cells and a rod-shaped medulla. Between them, there is the infundibular space and many trabeculae connect each other. Several tracheae insert into the papilla through the top of the medulla, then run into the cortical epithelium and locate in the intercellular space. The intercellular sinuses distribute in the posterior part of the rectal papilla.The cortex of the base divides into about thirty segments. Between segments there is a radial cell (Fig. 4). Under the cuticle, the apical cell membrane of the cortical epithelium is folded into a regular border of leaflets (Fig. 5).

scholarly journals The genus Gennadas (Benthesicymidae: Decapoda): morphology of copulatory characters, phylogeny and coevolution of genital structures

2017 ◽  
Vol 4 (12) ◽  
pp. 171288 ◽  
Author(s):  
Alexander L. Vereshchaka ◽  
Anastasia A. Lunina ◽  
Jørgen Olesen
Keyword(s):  
New Species ◽  
Anterior Part ◽  
Phylogenetic Analyses ◽  
Posterior Part ◽  
Key To Species ◽  
Internal Part ◽  
Species Groups ◽  
Aristaeomorpha Foliacea ◽  
External Part ◽  
Scanning Electron

Species within Gennadas differ from each other largely only in male (petasma) and female (thelycum) copulatory characters, which were restudied in scanning electron microscopy and used as a basis for phylogenetic analyses. Twenty-six petasma characters and 49 thelycum characters were identified. All 16 recognized species of Gennadas and Aristaeomorpha foliacea (outgroup) were included as terminals. Four robust monophyletic clades were retrieved, described and diagnosed as new species groups. The thelycum characters had greater impact on tree topology and supported deeper nodes than did the petasma characters. We hypothesize that features of the thelycum evolved first followed by aspects of the petasma. Relatively more conservative characters include parts of the sternites of the thelycum and of the petasma, while the scuti and protuberances on the thelycum and the shape and subdivisions of the petasma lobes are evolutionarily plastic. We identified two groups of copulatory characters, which are likely coupled functionally and interlinked evolutionarily: (i) the external part of the petasma and the posterior part of the thelycum and (ii) the internal part of the petasma and anterior part of the thelycum. We reconstruct possible mating position during copulation for each of the new species groups presented here. We also present an updated key to genera of Benthesicymidae and key to species of Gennadas .

scholarly journals Organization of the flagellar apparatus and associate cytoplasmic microtubules in the quadriflagellate alga Polytomella agilis.

1976 ◽  
Vol 69 (1) ◽  
pp. 106-125 ◽  
Author(s):  
D L Brown ◽  
A Massalski ◽  
R Patenaude
Keyword(s):  
Anterior Part ◽  
Flagellar Apparatus ◽  
Microtubule Assembly ◽  
Immunofluorescent Staining ◽  
Body Region ◽  
Basal Bodies ◽  
Cytoplasmic Microtubule ◽  
Large Numbers ◽  
Attachment Sites ◽  
Cytoplasmic Microtubules

The organization of microtubular systems in the quadriflagellate unicell Polytomella agilis has been reconstructed by electron microscopy of serial sections, and the overall arrangement confirmed by immunofluorescent staining using antiserum directed against chick brain tubulin. The basal bodies of the four flagella are shown to be linked in two pairs of short fibers. Light microscopy of swimming cells indicates that the flagella beat in two synchronous pairs, with each pair exhibiting a breast-stroke-like motion. Two structurally distinct flagellar rootlets, one consisting of four microtubules in a 3 over 1 pattern and the other of a striated fiber over two microtubules, terminate between adjacent basal bodies. These rootlets diverge from the basal body region and extend toward the cell posterior, passing just beneath the plasma membrane. Near the anterior part of the cell, all eight rootlets serve as attachment sites for large numbers of cytoplasmic microtubules which occur in a single row around the circumference of the cell and closely parallel the cell shape. It is suggested that the flagellar rootless may function in controlling the patterning and the direction of cytoplasmic microtubule assembly. The occurrence of similar rootlet structures in other flagellates is briefly reviewed.

Interacting functions of snail, twist and huckebein during the early development of germ layers in Drosophila

Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1137-1150 ◽  
Author(s):  
R. Reuter ◽  
M. Leptin
Keyword(s):  
Transcription Factors ◽  
Digestive Tract ◽  
Early Development ◽  
Target Genes ◽  
Anterior Part ◽  
Posterior Part ◽  
Germ Layers ◽  
Mesoderm Development ◽  
Ventral Furrow

Two zygotic genes, snail (sna) and twist (twi), are required for mesoderm development, which begins with the formation of the ventral furrow. Both twi and sna are expressed ventrally in the blastoderm, encode transcription factors and promote the invagination of the ventral furrow by activating or repressing appropriate target genes. However, sna and twi alone do not define the position of the ventral furrow, since they are also expressed in ventral cells that do not invaginate. We show that huckebein (hkb) sets the anterior and the posterior borders of the ventral furrow, but acts by different modes of regulation. In the posterior part of the blastoderm, hkb represses the expression of sna in the endodermal primordium (which we suggest to be adjacent to the mesodermal primordium). In the anterior part, hkb antagonizes the activation of target genes by twi and sna. Here, bicoid permits the co-expression of hkb, sna and twi, which are all required for the development of the anterior digestive tract. We suggest that mesodermal fate is determined where sna and twi but not hkb are expressed. Anteriorly hkb together with sna determines endodermal fate, and hkb together with sna and twi are required for foregut development.

scholarly journals A new species of Pista Malmgren, 1866 (Polychaeta, Terebellidae) from the north-western Mediterranean Sea

ZooKeys ◽  
2019 ◽  
Vol 838 ◽  
pp. 71-84
Author(s):  
Céline Labrune ◽  
Nicolas Lavesque ◽  
Paulo Bonifácio ◽  
Pat Hutchings
Keyword(s):  
New Species ◽  
Mediterranean Sea ◽  
Anterior Part ◽  
Posterior Part ◽  
Western Mediterranean ◽  
Single Pair ◽  
The North ◽  
Western Mediterranean Sea ◽  
North Western ◽  
A New Species

A new species of Terebellidae, Pistacolinisp. n., has been identified from the harbour of Banyuls-sur-Mer, north-western Mediterranean Sea. This new species was found in very high densities, exclusively in gravelly sand deposited manually, and was not found in the original source habitat of the gravel. This species is characterized by the colour of the ventral shields with pinkish anterior part and a blood red posterior part in live specimens, a pair of unequal-sized plumose branchiae inserted on segment II and anterior thoracic neuropodia with long-handled uncini. The presence of long-handled uncini even in the smallest specimens constitutes the major difference between Pistacolinisp. n. and other Pista species with a single pair of branchiae such as P.lornensis and P.bansei.

scholarly journals Influence of different orientations and rates of bidirectional distraction osteogenesis of the mandibular corpus: a three-dimensional study.

2019 ◽  
Vol S (1) ◽  
pp. 11-14
Author(s):  
Lamiaa A. Hasan ◽  
◽  
Nada M. Al-Sayagh ◽  
Lara R. Al-Banaa ◽  
◽  
...  
Keyword(s):  
Distraction Osteogenesis ◽  
Anterior Part ◽  
Three Dimensional ◽  
Posterior Part ◽  
Von Mises Stress ◽  
Occlusal Plane ◽  
Three Dimensional Model ◽  
Direction Parallel ◽  
Inferior Border ◽  
Von Mises

Objective: The objective of this study was to evaluate the biomechanical effect of mandibular corpus distraction osteogenesis with different orientations and rates. Materials and Methods: A three-dimensional model of the mandible was created. The vertical surgical cut was made, the force was applied horizontally in a bidirectional manner within two orientations: parallel to the occlusal plane and parallel to the inferior border of the mandible with three rates (0.5mm, 1mm and 1.5mm). Results: The maximum values for von Mises stress when the force was applied parallel to the inferior border of the mandible with all three rates were smaller than those with force direction parallel to the occlusal plane. The displacement in all three directions x, y, and z were not parallel and prominent in the anterior part of the mandible, while the movement at the posterior part is negligible, x and z displacement were bigger when force was applied parallel to the inferior border of the mandible, z displacement was more prominent than x and y displacement, both directions produced upward rotation of the mandible, this rotation was more noticeable when the force was applied parallel to the inferior border of the mandible. Conclusions: A vertical cut can be used in the patient with a long anterior face. This site of distraction achieves more lengthening of mandible than expansion.

TERMINOLOGY OF PALEOZOIC PLACODERM FISHES (ANTIARCHI) EXOSKELETAL ELEMENTS

2021 ◽  
Vol 43 (2) ◽  
pp. 195-201
Author(s):  
Sergey Moloshnikov ◽  
Keyword(s):  
Anterior Part ◽  
Posterior Part ◽  
Shoulder Girdle ◽  
Russian Language ◽  
Postcranial Skeleton ◽  
Incorrect Conclusion ◽  
Similar Term ◽  
Early Vertebrates ◽  
Language Literature ◽  
Dorsal Scute

The terminology and morphology of plates of the posterior part of the antiarch head shield (Placodermi, Antiarchi) are discussed. The terms «zatilochnaya» and «bokovaya (kraevaya) zatilochnaya» was previously accepted in antiarch skulls and are suggested for use in Russian-language literature. These terms are more correct and clearly define a position and development of these plates in the head shield of antiarchs. The titles «zagrivkovaya (nuchalnaya)» and «bokovaya zagrivkovaya (paranuchalnaya)», recently applied to them in Russian-language literature may indicate a connection in development with an anterior part of a trunk. A similar term is used for acipenserid exoskeleton. The acipenserid «nuchalnaya kost’» is located posterior to the «verchnezatilochnaya» (after Gurtovoi), and embryonically developed in an anterior part of the trunk over basidorsals and bones of the shoulder girdle. The name «pervaya spinnaya plastinka» (first dorsal scute: after Hilton and others) is also use for this bone. The term «zagrivkovaya plastinka» is used in other vertebrate skeletons, for example, in turtles; this name denotes the unpaired element of a carapace (postcranial skeleton). Using the terms «zagrivkovaya (nuchalnaya)» and «bokovaya zagrivkovaya (paranuchalnaya)» in the morphology of antiarchs and other placoderms may lead confusion in the terminology of skeletal elements at early vertebrates, incorrect conclusion of their homology, structure and development of the head shield of these unusual fishes.

Hedgehog organises the pattern and polarity of epidermal cells in the Drosophila abdomen

Development ◽  
1997 ◽  
Vol 124 (11) ◽  
pp. 2143-2154 ◽  
Author(s):  
G. Struhl ◽  
D.A. Barbash ◽  
P.A. Lawrence
Keyword(s):  
Anterior Part ◽  
Posterior Part ◽  
Cell Types ◽  
Epidermal Cells ◽  
Concentration Gradients ◽  
Cell Pattern ◽  
Different Cell Types ◽  
Adult Drosophila

The abdomen of adult Drosophila, like that of other insects, is formed by a continuous epithelium spanning several segments. Each segment is subdivided into an anterior (A) and posterior (P) compartment, distinguished by activity of the selector gene engrailed (en) in P but not A compartment cells. Here we provide evidence that Hedgehog (Hh), a protein secreted by P compartment cells, spreads into each A compartment across the anterior and the posterior boundaries to form opposing concentration gradients that organize cell pattern and polarity. We find that anteriorly and posteriorly situated cells within the A compartment respond in distinct ways to Hh: they express different combinations of genes and form different cell types. They also form polarised structures that, in the anterior part, point down the Hh gradient and, in the posterior part, point up the gradient - therefore all structures point posteriorly. Finally, we show that ectopic Hh can induce cells in the middle of each A compartment to activate en. Where this happens, A compartment cells are transformed into an ectopic P compartment and reorganise pattern and polarity both within and around the transformed tissue. Many of these results are unexpected and lead us to reassess the role of gradients and compartments in patterning insect segments.

scholarly journals MR Imaging of Intra- and Periarticular Cyst-Like Lesions of the Knee Joint in Workers with Occupational Kneeling

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Søren Rytter ◽  
Lilli Kirkeskov Jensen ◽  
Jens Peter Bonde ◽  
Niels Egund
Keyword(s):  
Knee Joint ◽  
Regression Models ◽  
Anterior Part ◽  
Knee Injuries ◽  
Posterior Part ◽  
Popliteus Tendon ◽  
Cystic Lesions ◽  
Logistic Regression Models ◽  
Significant Difference ◽  
Fluid Collections

Objective. To determine the risk of intra- and periarticular cyst-like lesions of the knee joint in occupational kneeling.Methods. Magnetic resonance imaging of both knees (n=282) was conducted in 92 male floor layers and 49 male graphic designers (referents), with a mean age of 55.6 years (range 42–70 years). The prevalence of cyst-like lesions was computed among floor layers and graphic designers, respectively, and associations with occupation summarized by odds ratio (OR) with 95% confidence intervals (CIs). Using logistic regression, models were adjusted for age, body mass index, knee injuries, and knee-straining sports.Results. Floor layers had a significantly higher prevalence of cyst-like lesions in the posterior part of the knee joint compared to graphic designers (OR 2.70, 95% CI 1.50–4.84). Floor layers also had a higher prevalence of fluid collections in the popliteus tendon recess (OR 2.17, 95% CI 0.99–4.77) and large cystic lesions of the popliteus muscle (OR 3.83, 95% CI 0.78–18.89). The prevalence of cystic lesions in the anterior part of the knee joint was low among floor layers (8.7%) and there was no significant difference between the two trade groups (P=0.34).Conclusions. Occupational kneeling increases the risk of cyst-like lesions in the posterior part of the knee joint.

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