scholarly journals Histology of the LarvalNeodiprion abietis(Hymenoptera: Diprionidae) Digestive Tract

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Christopher J. Lucarotti ◽  
Beatrixe H. Whittome-Waygood ◽  
David B. Levin

The alimentary canal ofNeodiprion abietislarvae is a straight tube divided into foregut, midgut, and hindgut. Posterior to the mouth, the foregut is further divided into the pharynx, esophagus (crop), and proventriculus, all of which are lined with cuticle. A pair of muscular, chitin-lined pouches branch off the anterior foregut and lie lateral to the alimentary canal. Gastric caeca are located at the anterior end of the midgut, where the peritrophic membrane is formed and was observed throughout the midgut. A single layer of midgut columnar epithelial cells abuts on the basal lamina at one end with microvilli extending into the gut lumen at the other. Nidi of regenerative cells were observed between columnar epithelial cells at the basal lamina. Malpighian tubules are attached to the posterior end of the midgut. The hindgut consists of the pylorus, a muscular ileum connecting to a bulbous rectum, which then opens to the anus.

1932 ◽  
Vol 55 (2) ◽  
pp. 307-323 ◽  
Author(s):  
H. Mooser ◽  
M. Ruiz Castaneda

The virus of Mexican typhus has been shown to multiply abundantly in the following species of fleas: Xenopsylla cheopis, Ceratophyllus fasciatus, Leptopsylla musculi, Ctenocephalus canis, Ctenocephalus felis. In all fleas, Rickettsia prowazeki was demonstrated within the epithelial cells of the stomach and within the cells of the Malpighian tubules. Whereas in infected lice enormous numbers of these organisms are discharged from the disintegrating cells into the intestinal content, only few Rickettsiae are found in the lumen of the fleas' intestines. They are held back by the peritrophic membrane, which covers the mucosa of the entire stomach. Rickettsiae seem to enter the lumen of the gut almost exclusively by the route of the Malpighian tubules. Observations were made which seem to indicate that the fleas recover from the infection and that they are able to regenerate the partly destroyed intestinal mucosa. An explanation is given for the relative harmlessness of fleas as vectors of typhus.


2000 ◽  
Vol 132 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Carlos Garcia-Salazar ◽  
F.E. Gildow ◽  
S.J. Fleischer ◽  
D. Cox-Foster ◽  
F.L. Lukezic

AbstractWe describe the morphology of the alimentary canal in adult Acalymma vittata (F.), the vector of Erwinia tracheiphila (Smith) Bergey et al. emend. Hauben et al. (Enterobacteriaceae), the causal agent of bacterial wilt in cucurbits (Cucurbitaceae). The foregut includes a pre-oral cavity, pharynx, oesophagus, and crop but lacks a well-developed proventriculus. The midgut occupies approximately 65% of the length of the gut, has distinctive ventricular crypts throughout its length, and is lined with a peritrophic membrane, but lacks caeca for harboring symbionts. The hindgut comprises the colon and rectum and four Malpighian tubules. The cuticular intima of both foregut and hindgut bears rows of spines and is thrown into numerous folds. Transmission electron microscopy showed bacteria resembling E. tracheiphila within the hindgut 1 and 30 d after the beetles fed on E. tracheiphila spread between cotyledons of cucumber, Cucumis sativus L. (Cucurbitaceae). Our observations suggest that the midgut is not appropriate for long-term retention of E. tracheiphila because of the absence of caeca and the presence of a peritrophic membrane. Temporary and long-term pathogen retention may be associated with rows of spines and numerous folds within the foregut and hindgut.


Reproduction ◽  
2000 ◽  
pp. 221-228 ◽  
Author(s):  
HF Irving-Rodgers ◽  
RJ Rodgers

Different morphological phenotypes of follicular basal lamina and of membrana granulosa have been observed. Ten preantral follicles (< 0. 1 mm), and 17 healthy and six atretic antral follicles (0.5-12 mm in diameter) were processed for light and electron microscopy to investigate the relationship the between follicular basal lamina and membrana granulosa. Within each antral follicle, the shape of the basal cells of the membrana granulosa was uniform, and either rounded or columnar. There were equal proportions of follicles </= 4 mm in diameter with columnar basal cells and with rounded basal cells. Larger follicles had only rounded basal cells. Conventional basal laminae of a single layer adjacent to the basal granulosa cells were observed in healthy follicles at the preantral and antral stages. However, at the preantral stage, the conventional types of basal lamina were enlarged or even partially laminated. A second type of basal lamina, described as 'loopy', occurred in about half the preantral follicles and in half the antral follicles </= 4 mm diameter. 'Loopy' basal laminae were not observed in larger follicles. 'Loopy' basal laminae were composed of basal laminae aligning the basal surface of basal granulosa cells, but with additional layers or loops often branching from the innermost layer. Each loop was usually < 1 microm long and had vesicles (20-30 nm) attached to the inner aspect. Basal cellular processes were also common, and vesicles could be seen budding off from these processes. In antral follicles, conventional basal laminae occurred in follicles with rounded basal granulosa cells. Other follicles with columnar cells, and atretic follicles, had the 'loopy' basal lamina phenotype. Thus, follicles have different basal laminae that relate to the morphology of the membrana granulosa.


Micron ◽  
2017 ◽  
Vol 100 ◽  
pp. 34-37 ◽  
Author(s):  
Anita Giglio ◽  
Ida Daniela Perrotta ◽  
Pietro Brandmayr

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Surman Arya ◽  
Suneel Kumar Singh

The digestive and tracheal system of a poultry shaft louse, Menopon gallinae (Phthiraptera: Amblycera) has been studied in greater details. Alimentary canal of louse was dissected out along with crop under stereozoom binocular microscope. Entire alimentary canal of M. gallinae was found more or less straight and has three basic parts (fore-gut, mid-gut and hind-gut) while crop-teeth was present in the crop. The posterior end of crop contains 20-30 well developed crop-teeth arranged in a single arced plate, in comb-like fashion. Mid-gut was found as simple tube and contributes nearly one half of the total length, while the hind-gut was marked by the opening of Malpighian tubules in alimentary canal. The heart of M. gallinae is of simplest kind, one chambered bulbous structure having three pairs of laterally placed ostia and supported by four pairs of alary muscles. In the tracheal system there were seven pairs of spiracles occurred on the terga of M. gallinae. The first pair of spiracle was found located close to legs while remaining six abdominal spiracles occur from segment 3rd to 8th. The degree of tracheation of various visceral organs has also been noted.


1958 ◽  
Vol 32 (4) ◽  
pp. 211-218 ◽  
Author(s):  
W. M. Fitzsimmons

This worm was very abundant in the rectum of a tortoise, Homopus femoralis, from the Bloemfontein area, Orange Free State, South Africa. It was found together with several other oxyurids the description of which will form the subject of a later paper. Although the Probstmayria far exceeded the other oxyurids in number, male specimens of this genus were extremely rare for only one male was found after a prolonged search during the course of which many hundreds of females were encountered. In order that no specimens should be lost the entire alimentary canal together with its contents was submerged in hot 70% alcohol after scraping the mucosa.


1939 ◽  
Vol s2-81 (323) ◽  
pp. 451-478
Author(s):  
S. PRADHAN

The paper incorporates: 1. The anatomy of the alimentary canal of Coccinella septempunctata as a type of carnivorous Coccinellid. 2. A detailed account of the extrinsic musculature and the nerve-supply of the cephallic stomodaeum, which have been studied in very few insects and never in Coccinellids. 3. The histology of the alimentary canal, specially the midgut, distinguishing four definite types of epithelium, one of which is surprisingly peculiar and has not been described before. This type of epithelium shows apparently two layers of cells, one superimposed over the other, the outer having large, regularly arranged, intercellular vacuoles as have not been described before, at least in the gut of insects. 4. A discussion on the relations of the four types of epithelium to one another, recognizing that this peculiar type of epithelium is just a phase in a unique process of Pro-epithelial Regeneration in the mid-gut epithelium. 5. A comparison of the chief characteristics of the alimentary canal of carnivorous and herbivorous Coccinellids based on the study of seven species of lady-bird beetles. 6. Probable explanations of the differences between the alimentary canals of the carnivorous and herbivorous Coccinellids.


1997 ◽  
Vol 110 (16) ◽  
pp. 1919-1934
Author(s):  
M. Murate ◽  
Y. Kishimoto ◽  
T. Sugiyama ◽  
T. Fujisawa ◽  
H. Takahashi-Iwanaga ◽  
...  

Hydra tissue consists of the ectodermal and the endodermal layers. When the two layers were separated by procaine treatment and then recombined, the ectodermal epithelial cells spread as a single cell layer over the endoderm as in epiboly in vertebrate embryogenesis, and the resultant spherical structure subsequently regenerated into a complete hydra. In this study, light and electron microscopy were used to examine the structural changes which took place in the cells and tissue during this epibolic ectodermal spreading process. Within a few hours after tissue recombination, the endoderm underwent dramatic changes; it lost its epithelial sheet organization, and turned into a mass of irregularly shaped cells without the apical-basal cell polarity initially present. In contrast, the ectoderm maintained its basic epithelial sheet organization as it spread over the endoderm. Later, the endodermal epithelial cells reorganized themselves into a single-layered epithelial sheet underneath the spreading ectodermal layer. The resultant spherical structure consisted of a single layer of ectodermal epithelial cells outside, a single layer of endodermal epithelial cells inside, and an empty cavity in the center as in normal hydra tissue. This structure regenerated into hydra in the following days. These and other observations demonstrate that the two-layered epithelial sheet organization is highly dynamic, and that its stability is maintained by strong interactions between the two layers in normal hydra. It is suggested that this dynamic nature of the hydra tissue, particularly the high plasticity of the endodermal epithelial sheet organization, may be an important element for the high regenerative capacity of this organism.


2021 ◽  
Vol 11 (12) ◽  
pp. 2329-2336
Author(s):  
Qiang Zeng ◽  
Yiting Luo

In order to explore effects of long-chain non-coding ribonucleic acid (RNA) HOTAIR on proliferation and migration of human lens epithelial cells, SRA01/04 cells were selected as the research strain in this study and divided into S1 group (no HOTAIR transfection), S2 group (siHOTAIR transfection), S3 group (siHOTAIR+10 ng/mL TGF-β2), and S4 group (no HOTAIR transfection+10 ng/mL TGF-β2) according to the presence or absence of transforming growth factor (TGF)-β2 and silent HOTAIR treatment. 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) colorimetric method was applied to detect cell proliferation.Western blot was used for detection of E-cadherin, zonula occluden-1 (ZO-1), Vimentin, α-smooth muscle actin (SMA), Snail, Slug, zinc finger E-box binding homeobox 1 (ZEB1), and Smad-2 expressions. Results showed that the number of transmembrane cells in S4 group was higher markedly than that of the other groups, but that of S2 group dropped steeply compared with the other groups (P <0.05); E-cadherin (2.59±0.58) and ZO-1 (1.95±0.56) of S2 group increased hugely compared with the other groups, while Vimentin (0.57±0.14) and α-SMA (0.64±0.28) decreased sharply compared with the other groups (P < 0.05); Snail (2.51±0.59), Slug (2.11±0.47), and ZEB1 (2.83±0.53) of S4 group rose obviously compared with the other groups, but the above of S2 group reduced hugely compared with the other groups (P < 0.05); pSmad-2 and pSmad-3 of S4 group elevated greatly compared with the other groups, and those of S2 group reduced hugely compared with the other groups (P < 0.05). In conclusion, HOTAIR high expression could promote TGF-β2-induced SRA01/04 cell proliferation, migration, invasion, and epithelial-mesenchymal trans-differentiation, which was related to TGF-β/Smad signaling pathway.


1989 ◽  
Vol 257 (1) ◽  
pp. G86-G93
Author(s):  
F. R. Homaidan ◽  
M. Donowitz ◽  
G. A. Weiland ◽  
G. W. Sharp

The actions of three different types of calcium channel blockers on short-circuit current (Isc) in rabbit ileum were studied. These included the phenylalkylamines, verapamil and (l)-desmethoxyverapamil (D888); the dihydropyridines, nifedipine and nitrendipine; and the benzothiazepine, diltiazem. All of the drugs decreased Isc, a change associated with increased Na and Cl absorption. Verapamil and D888 had the largest effects. The dihydropyridine, BAY K 8644, a calcium channel activator, increased Isc and decreased Na and Cl absorption, effects not inhibited by tetrodotoxin. The phenylalkylamines had an additional effect on Isc in the presence of a maximally inhibitory concentration of the dihydropyridines, suggesting the possibility of two distinct calcium channels, one of which is the L-type voltage-activated, dihydropyridine- and phenylalkylamine-sensitive channel, and the other is a channel only sensitive to phenylalkylamines but not to dihydropyridines. [3H]nitrendipine and [3H]D888 binding to an enriched preparation of basolateral membranes from ileal epithelial cells was characterized. Each ligand bound specifically and saturably to an apparently single population of high-affinity sites with [3H]D888 having three times as many binding sites as [3H]nitrendipine. [3H]nitrendipine binding was partially inhibited by verapamil and D888 and was increased by diltiazem; whereas [3H]D888 binding was inhibited completely by verapamil but only partially by nitrendipine and diltiazem. These transport and binding studies suggest the presence of two types of Ca2+ channels in ileal epithelial cells, one of which interacts with the dihydropyridines, the phenylalkylamines, and the benzothiazepines at three different sites and the other channel that only binds the phenylalkylamines.


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