Cytochemistry, morphogenesis, and tentative identification of mycetomal microorganisms of Sitophilus granarius L. (Coleoptera)

1970 ◽  
Vol 16 (12) ◽  
pp. 1357-1362 ◽  
Author(s):  
R. D. S. Bhatnagar ◽  
A. J. Musgrave
Keyword(s):  
Life Cycle ◽  
Sitophilus Granarius ◽  
Tentative Identification ◽  
Life Cycle Stages ◽  
Present Life

The mycetomal microorganisms of Sitophilus granarius (L.) (Coleoptera) are flexible, non acid-fast, non-flagellated rods, often surrounded by mucoid material. Pleomorphic and involution forms are present. Life cycle stages have been observed. The literature on these organisms is briefly reviewed. As they have never been cultured in vitro and the literature indicates this may be very difficult or even impossible, a postulate of Murray's regarding identification of symbiotes by morphology is invoked and the mycetomal microorganisms (plasmids, Blochmann bodies) in this insect are tentatively referred to the Myxobacterales (sens. lat.).

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.

scholarly journals Developmental regulation of edited CYb and COIII mitochondrial mRNAs is achieved by distinct mechanisms in Trypanosoma brucei

2020 ◽  
Vol 48 (15) ◽  
pp. 8704-8723
Author(s):  
Joseph T Smith Jr. ◽  
Eva Doleželová ◽  
Brianna Tylec ◽  
Jonathan E Bard ◽  
Runpu Chen ◽  
...  
Keyword(s):  
Life Cycle ◽  
Trypanosoma Brucei ◽  
High Throughput Sequencing ◽  
Environmental Changes ◽  
Developmental Regulation ◽  
Complex Life Cycle ◽  
Mrna Levels ◽  
Developmentally Regulated ◽  
Life Cycle Stages

Abstract Trypanosoma brucei is a parasitic protozoan that undergoes a complex life cycle involving insect and mammalian hosts that present dramatically different nutritional environments. Mitochondrial metabolism and gene expression are highly regulated to accommodate these environmental changes, including regulation of mRNAs that require extensive uridine insertion/deletion (U-indel) editing for their maturation. Here, we use high throughput sequencing and a method for promoting life cycle changes in vitro to assess the mechanisms and timing of developmentally regulated edited mRNA expression. We show that edited CYb mRNA is downregulated in mammalian bloodstream forms (BSF) at the level of editing initiation and/or edited mRNA stability. In contrast, edited COIII mRNAs are depleted in BSF by inhibition of editing progression. We identify cell line-specific differences in the mechanisms abrogating COIII mRNA editing, including the possible utilization of terminator gRNAs that preclude the 3′ to 5′ progression of editing. By examining the developmental timing of altered mitochondrial mRNA levels, we also reveal transcript-specific developmental checkpoints in epimastigote (EMF), metacyclic (MCF), and BSF. These studies represent the first analysis of the mechanisms governing edited mRNA levels during T. brucei development and the first to interrogate U-indel editing in EMF and MCF life cycle stages.

scholarly journals The Life Cycle Stages of Pneumocystis murina Have Opposing Effects on the Immune Response to This Opportunistic Fungal Pathogen

2016 ◽  
Vol 84 (11) ◽  
pp. 3195-3205 ◽  
Author(s):  
Heather M. Evans ◽  
Grady L. Bryant ◽  
Beth A. Garvy
Keyword(s):  
Cell Wall ◽  
Life Cycle ◽  
Immune Responses ◽  
Immune Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Content Type ◽  
Life Cycle Stages ◽  
Ifn Γ

The cell wall β-glucans of Pneumocystis cysts have been shown to stimulate immune responses in lung epithelial cells, dendritic cells, and alveolar macrophages. Little is known about how the trophic life forms, which do not have a fungal cell wall, interact with these innate immune cells. Here we report differences in the responses of both neonatal and adult mice to the trophic and cystic life cycle stages of Pneumocystis murina . The adult and neonatal immune responses to infection with Pneumocystis murina trophic forms were less robust than the responses to infection with a physiologically normal mixture of cysts and trophic forms. Cysts promoted the recruitment of nonresident innate immune cells and T and B cells into the lungs. Cysts, but not trophic forms, stimulated increased concentrations of the cytokine gamma interferon (IFN-γ) in the alveolar spaces and an increase in the percentage of CD4 + T cells that produce IFN-γ. In vitro , bone marrow-derived dendritic cells (BMDCs) stimulated with cysts produced the proinflammatory cytokines interleukin 1β (IL-1β) and IL-6. In contrast, trophic forms suppressed antigen presentation to CD4 + T cells, as well as the β-glucan-, lipoteichoic acid (LTA)-, and lipopolysaccharide (LPS)-induced production of interleukin 1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α) by BMDCs. The negative effects of trophic forms were not due to ligation of mannose receptor. Our results indicate that optimal innate and adaptive immune responses to Pneumocystis species are dependent on stimulation with the cyst life cycle stage. Conversely, trophic forms suppress β-glucan-induced proinflammatory responses in vitro , suggesting that the trophic forms dampen cyst-induced inflammation in vivo .

Morphological characterization ofCryptosporidium parvumlife-cycle stages in anin vitromodel system

Parasitology ◽  
2009 ◽  
Vol 137 (1) ◽  
pp. 13-26 ◽  
Author(s):  
H. BOROWSKI ◽  
R. C. A. THOMPSON ◽  
T. ARMSTRONG ◽  
P. L. CLODE
Keyword(s):  
Electron Microscopy ◽  
Life Cycle ◽  
Protozoan Parasite ◽  
Morphological Characterization ◽  
Host Cells ◽  
Epithelial Cell Line ◽  
Life Cycle Stages ◽  
Complete Life Cycle ◽  
Behavioural Characteristics

SUMMARYCryptosporidium parvumis a zoonotic protozoan parasite that mainly affects the ileum of humans and livestock, with the potential to cause severe enteric disease. We describe the complete life cycle ofC. parvumin anin vitrosystem. Infected cultures of the human ileocecal epithelial cell line (HCT-8) were observed over time using electron microscopy. Additional data are presented on the morphology, development and behavioural characteristics of the different life-cycle stages as well as determining their time of occurrence after inoculation. Numerous stages ofC. parvumand their behaviour have been visualized and morphologically characterized for the first time using scanning electron microscopy. Further, parasite-host interactions and the effect ofC. parvumon host cells were also visualized. An improved understanding of the parasite's biology, proliferation and interactions with host cells will aid in the development of treatments for the disease.

Intron-containing β-tubulin transcripts in Cryptosporidium parvum cultured in vitro

Microbiology ◽  
2004 ◽  
Vol 150 (5) ◽  
pp. 1191-1195 ◽  
Author(s):  
Xiaomin Cai ◽  
Cheryl A. Lancto ◽  
Mitchell S. Abrahamsen ◽  
Guan Zhu
Keyword(s):  
Life Cycle ◽  
Cryptosporidium Parvum ◽  
Late Life ◽  
Host Cells ◽  
Intron Splicing ◽  
Transcript Processing ◽  
Life Cycle Stages ◽  
Tubulin Mrna

The genome of Cryptosporidium parvum contains a relatively small number of introns, which includes the β-tubulin gene with only a single intron. Recently, it was observed that the intron was not removed from some of the β-tubulin transcripts in the late life cycle stages cultured in vitro. Although normally spliced β-tubulin mRNA was detected in all parasite intracellular stages by RT-PCR (e.g. HCT-8 or Caco-2 cells infected with C. parvum for 12–72 h), at 48–72 h post-infection unprocessed β-tubulin transcripts containing intact introns started to appear in parasite mRNA within infected host cells. The intron-containing transcripts could be detected by fluorescence in situ hybridization (FISH) using an intron-specific probe. The intron-containing β-tubulin transcripts appeared unique to the in vitro-cultured C. parvum, since they were not detected in parasite-infected calves at 72 h. As yet, it is unclear whether the late life cycle stages of C. parvum are partially deficient in intron-splicing or the intron-splicing processes have merely slowed, both of which would allow the detection of intron-containing transcripts. Another possible explanation is that the decay in transcript processing might simply be due to the onset of parasite death. Nonetheless, the appearance of intron-containing transcripts coincides with the arrest of C. parvum development in vitro. This unusual observation prompts speculation that the abnormal intron-splicing of β-tubulin transcripts may be one of the factors preventing complete development of this parasite in vitro. Furthermore, the presence of both processed and unprocessed introns in β-tubulin transcripts in vitro may provide a venue for studying overall mechanisms for intron-splicing in this parasite.

scholarly journals Monoclonal Antibodies to Intracellular Stages ofCryptosporidium parvumDefine Life Cycle ProgressionIn Vitro

mSphere ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Georgia Wilke ◽  
Soumya Ravindran ◽  
Lisa Funkhouser-Jones ◽  
Jennifer Barks ◽  
Qiuling Wang ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Life Cycle ◽  
Gastrointestinal Disease ◽  
Epithelial Cell Line ◽  
Type I ◽  
Parasite Life Cycle ◽  
Major Barrier ◽  
Content Type ◽  
Life Cycle Stages

ABSTRACTAmong the obstacles hinderingCryptosporidiumresearch is the lack of anin vitroculture system that supports complete life development and propagation. This major barrier has led to a shortage of widely available anti-Cryptosporidiumantibodies and a lack of markers for staging developmental progression. Previously developed antibodies againstCryptosporidiumwere raised against extracellular stages or recombinant proteins, leading to antibodies with limited reactivity across the parasite life cycle. Here we sought to create antibodies that recognize novel epitopes that could be used to define intracellular development. We identified a mouse epithelial cell line that supportedC. parvumgrowth, enabling immunization of mice with infected cells to create a bank of monoclonal antibodies (MAbs) against intracellular parasite stages while avoiding the development of host-specific antibodies. From this bank, we identified 12 antibodies with a range of reactivities across the parasite life cycle. Importantly, we identified specific MAbs that can distinguish different life cycle stages, such as trophozoites, merozoites, type I versus II meronts, and macrogamonts. These MAbs provide valuable tools for theCryptosporidiumresearch community and will facilitate future investigation into parasite biology.IMPORTANCECryptosporidiumis a protozoan parasite that causes gastrointestinal disease in humans and animals. Currently, there is a limited array of antibodies available against the parasite, which hinders imaging studies and makes it difficult to visualize the parasite life cycle in different culture systems. In order to alleviate this reagent gap, we created a library of novel antibodies against the intracellular life cycle stages ofCryptosporidium. We identified antibodies that recognize specific life cycle stages in distinctive ways, enabling unambiguous description of the parasite life cycle. These MAbs will aid future investigation intoCryptosporidiumbiology and help illuminate growth differences between various culture platforms.

scholarly journals Long non-coding RNA levels can be modulated by 5-azacytidine in Schistosoma mansoni

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Murilo S. Amaral ◽  
Lucas F. Maciel ◽  
Gilbert O. Silveira ◽  
Giovanna G. O. Olberg ◽  
João V. P. Leite ◽  
...  
Keyword(s):  
Stem Cell ◽  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Drug Targets ◽  
Single Cells ◽  
Differentially Expressed ◽  
Protein Coding ◽  
Life Cycle Stages ◽  
Network Modules

AbstractSchistosoma mansoni is a flatworm that causes schistosomiasis, a neglected tropical disease that affects more than 200 million people worldwide. There is only one drug indicated for treatment, praziquantel, which may lead to parasite resistance emergence. The ribonucleoside analogue 5-azacytidine (5-AzaC) is an epigenetic drug that inhibits S. mansoni oviposition and ovarian development through interference with parasite transcription, translation and stem cell activities. Therefore, studying the downstream pathways affected by 5-AzaC in S. mansoni may contribute to the discovery of new drug targets. Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides with low or no protein coding potential that have been involved in reproduction, stem cell maintenance and drug resistance. We have recently published a catalog of lncRNAs expressed in S. mansoni life-cycle stages, tissues and single cells. However, it remains largely unknown if lncRNAs are responsive to epigenetic drugs in parasites. Here, we show by RNA-Seq re-analyses that hundreds of lncRNAs are differentially expressed after in vitro 5-AzaC treatment of S. mansoni females, including intergenic, antisense and sense lncRNAs. Many of these lncRNAs belong to co-expression network modules related to male metabolism and are also differentially expressed in unpaired compared with paired females and ovaries. Half of these lncRNAs possess histone marks at their genomic loci, indicating regulation by histone modification. Among a selected set of 8 lncRNAs, half of them were validated by RT-qPCR as differentially expressed in females, and some of them also in males. Interestingly, these lncRNAs are also expressed in other life-cycle stages. This study demonstrates that many lncRNAs potentially involved with S. mansoni reproductive biology are modulated by 5-AzaC and sheds light on the relevance of exploring lncRNAs in response to drug treatments in parasites.

scholarly journals Studies on the life cycle of Pleurogenoides wayanadensis Shinad & Prasadan, 2018 (Digenea: Pleurogenidae) from the Western Ghats, India

2020 ◽  
Vol 94 ◽  
Author(s):  
P.K. Prasadan ◽  
K. Shinad ◽  
C. Sherin ◽  
K. Arusha
Keyword(s):  
Life Cycle ◽  
Western Ghats ◽  
Freshwater Snail ◽  
Hoplobatrachus Tigerinus ◽  
Life Cycle Study ◽  
Life Cycle Stages ◽  
Fourth Report ◽  
Seventh Report ◽  
Present Life ◽  
The Western Ghats

Abstract The life cycle of Pleurogenoides wayanadensis Shinad & Prasadan, 2018, infecting the frogs Hoplobatrachus tigerinus and Euphlyctis cyanophlyctis, is elucidated in this study. All the life cycle stages from egg to egg-producing adults were elucidated under natural conditions and successfully established in the laboratory. The life cycle took about 58 to 65 days for completion. Miracidia were released by teasing the eggs with fine needles. Sporocysts were found in the freshwater snail, Bithynia (Digoniostoma) pulchella, collected from paddy fields at Payode, Western Ghats, Wayanad region, in the months of October and November 2019. Cercariae were of the virgulate xiphidiocercous type. Metacercariae were recovered from the eyes of the damselfly naiads of the species Ischnura sp. and Copera sp., and the thorax and abdomen of the dragonfly naiads, Orthetrum sp. The metacercariae showed progenetic development. The growth and development of the metacercariae in the naiads that were exposed to cercariae, and development of the trematode in frogs that were force-fed with encysted metacercariae, have been studied at regular intervals. The prepatent period is 14–19 days. The present life cycle study of a Pleurogenoides spp. forms the seventh report from the world, fourth report from India and the third from Kerala.

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