Histological study of external budding in Taenia crassiceps

1970 ◽  
Vol 18 (1) ◽  
pp. 1 ◽  
Author(s):  
FM Bilqees
Keyword(s):  
Life Cycle ◽  
Adult Worm ◽  
Histological Study ◽  
Laboratory Mouse ◽  
Serial Sections ◽  
Stages Of Development ◽  
Taenia Crassiceps ◽  
Whole Mounts ◽  
Usual Pattern

The life cycle of T, crassiceps, which grows to the adult worm in the intestine of dogs and other canids and to a cysticercus in the laboratory mouse and other rodents, deviates from the usual pattern for taeniids because the embryo not only grows but later reproduces asexually by exogenous budding either subcutaneously or in body cavities. Differentiation of the bud was followed by removing cestodes at various stages of development. Living specimens, whole mounts, and serial sections, fixed and stained by various methods, were used. The subtegumental cells appear to dominate the process of budding at the abscolex end of the metacestode. Usually the bud separates from the budder after the lacuna is formed. The study demonstrates the importance of the subtegumental cells in the growth and differentiation of buds.

Plagiorchis peterborensis sp. n. (Trematoda:Plagiorchiidae), a parasite of Lymnaea stagnalis appressa, reared in the laboratory mouse, Mus musculus

1968 ◽  
Vol 46 (2) ◽  
pp. 135-140 ◽  
Author(s):  
Bro. Joseph Kavelaars ◽  
T. K. R. Bourns
Keyword(s):  
Life Cycle ◽  
Aedes Aegypti ◽  
Mus Musculus ◽  
Egg Size ◽  
Lymnaea Stagnalis ◽  
Laboratory Mouse ◽  
Serial Sections ◽  
Laboratory Mice ◽  
Whole Mounts

Cercariae of Plagiorchis peterborensis sp. n. were obtained from Lymnaea stagnalis appressa, and the life cycle was completed using Aedes aegypti larvae and laboratory mice as experimental hosts. Description of the adult is based upon whole mounts and serial sections of 14-day-old worms. P. peterborensis resembles most closely P. muris, but differs in stylet shape, adult dimensions, and egg size.

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

Taeniasis in a German Shepherd Pup: A Case Report

2019 ◽  
Vol 15 (01) ◽  
pp. 83-84
Author(s):  
B J Thakre ◽  
Joice P Joseph ◽  
Binod Kumar ◽  
Nilima Brahmbhatt ◽  
Krishna Gamit
Keyword(s):  
Case Report ◽  
Life Cycle ◽  
Definitive Host ◽  
Gastrointestinal Diseases ◽  
Intermediate Hosts ◽  
German Shepherd ◽  
Taenia Hydatigena ◽  
Taenia Multiceps ◽  
Taenia Crassiceps ◽  
Dipylidium Caninum

Taenia spp. are long, segmented, parasitic tapeworms and are relatively uncommon in canine gastrointestinal diseases compared to other tapeworms like Dipylidium caninum. These parasites have an indirect life cycle, cycling between definitive and intermediate hosts. Dogs act as definitive hosts of different species of Taenia including Taenia multiceps, Taenia serialis, Taenia crassiceps, Taenia hydatigena, Taenia pisiformis, etc. Taenia multiceps is of greatest zoonotic relevance in human. In the definitive host, it causes only mild infection. Larvae are more likely to cause disease than adult tapeworms. Taeniasis in pets should be cautiously handled because of its zoonotic importance. This communication reports a case of 3 months old pup suffering from Taenia infection that was successfully managed with a combination of praziquantel and fenbendazole.

On the Anatomy of the Trematode Petasiger exaeretus Dietz 1909, from the Intestine of Phalacrocorax Carbo

Parasitology ◽  
1934 ◽  
Vol 26 (1) ◽  
pp. 133-137 ◽  
Author(s):  
Evan Davies
Keyword(s):  
Small Intestine ◽  
Type Species ◽  
Detailed Account ◽  
Serial Sections ◽  
Phalacrocorax Carbo ◽  
The Family ◽  
Whole Mounts

The genus Petasiger which belongs to the family Echinostomidae was proposed by Dietz in 1909, with Petasiger exaeretus as the type species. The description given by Dietz of this species is incomplete and it is proposed therefore to present below a more detailed account of the anatomy, based on an examination of whole mounts and serial sections. The material was obtained from the small intestine of cormorants shot on the coast of Cardigan Bay between Aberystwyth and Llanrhystyd. Five cormorants were shot in July, and of these two contained a large number of Petasiger exaeretus in the small intestine.

scholarly journals Studies on Amphibian Metamorphosis

1939 ◽  
Vol 16 (1) ◽  
pp. 96-120
Author(s):  
O. M. HELFF
Keyword(s):  
Great Majority ◽  
Gill Tissue ◽  
Shoulder Girdle ◽  
The Other ◽  
Histological Structure ◽  
Serial Sections ◽  
Stages Of Development ◽  
Amphibian Metamorphosis ◽  
The Right ◽  
Made In

(1) Opercular integument, homoplastically transplanted to the back and side of R. temporaria larvae, underwent a process of partial degeneration. The histolysis was not confined to any localized region of the transplant. (2) Autoplastic transplantation of opercular integument to the back and side produced a variety of results. Normal histological structure was maintained in certain transplants, generalized degeneration was observed in others, while in several instances localized histolysis resulting in perforation formation occurred. (3) Homoplastic and autoplastic transplantation of back and side skin to the opercular region resulted in histolysis and perforation formation in such transplants during larval involution. (4) The right forelimbs (in early stages of development) with attached portions of the shoulder girdle were extirpated in R. temporaria and B. bufo. During subsequent metamorphosis, normal opercular histolysis followed by perforation formation in many cases was observed. In most instances, serial sections of the peribranchial cavity revealed the absence of cutaneous glands. (5) Extirpation of the right forelimb only was made in the same two species. Opercular histolysis subsequently occurred in all instances, resulting in perforation formation in the great majority of cases during larval involution. In many of the B. bufo animals two separate perforations developed, one filled with limb stump and the other with gill tissue. (6) It is concluded that in R. temporaria a particular area of the operculum may in some individuals possess self-degenerative potentialities conducive to histolysis and perforation formation during metamorphosis. In both R. temporaria and B. bufo histolytic influences emanating from the atrophying gill tissue and the cutaneous glands of the forelimb are probably also responsible for opercular histolysis and perforation formation. Limb pressure must be considered a supplemental factor. (7) The results are discussed in general and attention called to the fact that opercular histolysis and perforation formation are "doubly assured" in some species and possibly even "triply assured" in others. Emphasis is placed on the evidently wide divergence between species as regards the particular combination of factors responsible for opercular histolysis and perforation formation. Apparently, no one explanation can serve to account for the phenomenon as it occurs in various species of anurans.

scholarly journals The Pre-Natal Development of Wool Follicles in Merino Sheep

1956 ◽  
Vol 9 (3) ◽  
pp. 423 ◽  
Author(s):  
Margaret H Hardy ◽  
AG Lyne
Keyword(s):  
Histological Study ◽  
Serial Sections ◽  
Merino Sheep

A histological study has been mado of wool folliclos in skin from the trunk of 24 shcep foetuses ranging in age from (J)) to 145 days of gestation. Fifteen of t.hese foetuses are known to be entirely Merino in origin, and the remainder are believed to be wholly or predominantly Merino. Extensive use has berm mado of serial sections parallel to the axis of the wool follicles as well as those parallel to [,he skin snrfaco. Skin from ]\lorino lambs and adults has also boen examined.

scholarly journals Molecular signatures of the rediae, cercariae and adult stages in the complex life cycles of parasitic flatworms (Digenea: Psilostomatidae)

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Maksim A. Nesterenko ◽  
Viktor V. Starunov ◽  
Sergei V. Shchenkov ◽  
Anna R. Maslova ◽  
Sofia A. Denisova ◽  
...  
Keyword(s):  
Gene Ontology ◽  
Life Cycle ◽  
Adult Worm ◽  
Differential Expression Analysis ◽  
Enrichment Analysis ◽  
Life Cycles ◽  
Molecular Signature ◽  
High Quality ◽  
Gene Ontology Enrichment Analysis ◽  
Gene Ontology Enrichment

Abstract Background Parasitic flatworms (Trematoda: Digenea) represent one of the most remarkable examples of drastic morphological diversity among the stages within a life cycle. Which genes are responsible for extreme differences in anatomy, physiology, behavior, and ecology among the stages? Here we report a comparative transcriptomic analysis of parthenogenetic and amphimictic generations in two evolutionary informative species of Digenea belonging to the family Psilostomatidae. Methods In this study the transcriptomes of rediae, cercariae and adult worm stages of Psilotrema simillimum and Sphaeridiotrema pseudoglobulus, were sequenced and analyzed. High-quality transcriptomes were generated, and the reference sets of protein-coding genes were used for differential expression analysis in order to identify stage-specific genes. Comparative analysis of gene sets, their expression dynamics and Gene Ontology enrichment analysis were performed for three life stages within each species and between the two species. Results Reference transcriptomes for P. simillimum and S. pseudoglobulus include 21,433 and 46,424 sequences, respectively. Among 14,051 orthologous groups (OGs), 1354 are common and specific for two analyzed psilostomatid species, whereas 13 and 43 OGs were unique for P. simillimum and S. pseudoglobulus, respectively. In contrast to P. simillimum, where more than 60% of analyzed genes were active in the redia, cercaria and adult worm stages, in S. pseudoglobulus less than 40% of genes had such a ubiquitous expression pattern. In general, 7805 (36.41%) and 30,622 (65.96%) of genes were preferentially expressed in one of the analyzed stages of P. simillimum and S. pseudoglobulus, respectively. In both species 12 clusters of co-expressed genes were identified, and more than a half of the genes belonging to the reference sets were included into these clusters. Functional specialization of the life cycle stages was clearly supported by Gene Ontology enrichment analysis. Conclusions During the life cycles of the two species studied, most of the genes change their expression levels considerably, consequently the molecular signature of a stage is not only a unique set of expressed genes, but also the specific levels of their expression. Our results indicate unexpectedly high level of plasticity in gene regulation between closely related species. Transcriptomes of P. simillimum and S. pseudoglobulus provide high quality reference resource for future evolutionary studies and comparative analyses.

scholarly journals Sm14 gene expression in different stages of the Schistosoma mansoni life cycle and immunolocalization of the Sm14 protein within the adult worm

2002 ◽  
Vol 35 (3) ◽  
pp. 377-381 ◽  
Author(s):  
C.F.A. Brito ◽  
G.C. Oliveira ◽  
S.C. Oliveira ◽  
M. Street ◽  
S. Riengrojpitak ◽  
...  
Keyword(s):  
Gene Expression ◽  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Adult Worm

Observations on the function of the choriothete and on egg hatching in Glossina spp. (Dipt., Glossinidae)

1973 ◽  
Vol 62 (3) ◽  
pp. 371-374 ◽  
Author(s):  
Michael J. Roberts
Keyword(s):  
Recent Work ◽  
Instar Larva ◽  
Serial Sections ◽  
Egg Hatching ◽  
Glossina Austeni ◽  
First Instar ◽  
Muscular Tension ◽  
Eggs And Larvae ◽  
Whole Mounts

The choriothete in Glossina austeni Newst. and G. morsitans Westw. was studied from serial sections of females, from dissected material and whole mounts of eggs and larvae. The choriothete cells are secretory and, while an embryo or first-instar larva is attached to it, are not stretched. The external muscles dilate the uterus or support the uterus and embryo. There is no sign of major folding or muscular tension during dechorionation of the egg. It is concluded, in contrast to recent work, that the choriothete is an organ for the support of developing embryos. Hatching of the first-instar larvae is probably achieved by means of a labral egg tooth.

Nippostrongylus brasiliensis: the effect of mitochondnal inhibitors on life-cycle stages

Parasitology ◽  
1984 ◽  
Vol 88 (1) ◽  
pp. 163-177 ◽  
Author(s):  
M. Fry ◽  
D. C. Jenkins
Keyword(s):  
Life Cycle ◽  
Electron Transport ◽  
Oxidative Phosphorylation ◽  
Adult Worm ◽  
Nippostrongylus Brasiliensis ◽  
Free Living ◽  
Mitochondrial Inhibitors ◽  
Life Cycle Stages ◽  
Transport Inhibitors

SUMMARYThe effects of mitochondrial inhibitors on the in vitro development of Nippostrongylus brasiliensis have been studied in free-living and parasitic life-cycle stages. Mitochondrial inhibitors were chosen as being representative of established electron transport inhibitors and oxidative phosphorylation inhibitors and uncouplers of the classical mammalian respiratory chain. All mitochondrial inhibitors tested were highly effective in killing or retarding development of free-living stages of N. brasiliensis. Free-living stages were particularly susceptible to such inhibitors upon hatching of embryonated eggs to 1st-stage larvae. Concentrations of inhibitors effective against free-living stages were consistent with their level of inhibition against isolated mitochondria from embryonated eggs and 3rd-stage infective larvae. Results suggest an absolute requirement in the development of free-living stages for the mammalian-like respiratory chain and associated oxidative phosphorylation. Electron transport inhibitors were effective in retarding at least the initial development of 4th-stage larvae to adults, but only antimycin A and azide produced a lasting effect leading to worm death. Oxidative phosphorylation inhibitors and uncouplers were ineffective against developing parasitic stages of N. brasiliensis. Experiments on whole-worm respiration indicated that most electron transport inhibitors were able to penetrate the adult worm, but oxidative phosphorylation inhibitors were without effect on whole-worm respiration. Results suggest that the mammalian-like electron transport chain is a necessary requirement to adult N. brasiliensis, but oxidative phosphorylation in the adult worm may not be required for development and survival in vitro although it could be necessary to support the parasite in vivo.

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