Cyst formation of Tubifex tubifex (M�ller) ? an adaptation to survive food deficiency and drought

Hydrobiologia ◽  
1990 ◽  
Vol 190 (1) ◽  
pp. 79-82 ◽  
Author(s):  
Andreas Anlauf
Keyword(s):  
Cyst Formation ◽  
Tubifex Tubifex ◽  
Food Deficiency

Cyst Formation by Tubifex tubifex (Tubificidae)

1981 ◽  
Vol 100 (1) ◽  
pp. 34 ◽  
Author(s):  
Jerry L. Kaster ◽  
John H. Bushnell
Keyword(s):  
Cyst Formation ◽  
Tubifex Tubifex

Neuron-glia relationship during the early postembryonic development of the nervous system in some oligochaetes

1978 ◽  
Vol 36 (2) ◽  
pp. 600-601
Author(s):  
Wiktor Djaczenko ◽  
Carmen Calenda Cimmino
Keyword(s):  
Nervous System ◽  
Glial Cells ◽  
Early Period ◽  
Postembryonic Development ◽  
Ruthenium Red ◽  
The Body ◽  
Tubifex Tubifex ◽  
Growth Stages ◽  
Cell Processes ◽  
Cytoplasmic Processes

The simplicity of the developing nervous system of oligochaetes makes of it an excellent model for the study of the relationships between glia and neurons. In the present communication we describe the relationships between glia and neurons in the early periods of post-embryonic development in some species of oligochaetes.Tubifex tubifex (Mull. ) and Octolasium complanatum (Dugès) specimens starting from 0. 3 mm of body length were collected from laboratory cultures divided into three groups each group fixed separately by one of the following methods: (a) 4% glutaraldehyde and 1% acrolein fixation followed by osmium tetroxide, (b) TAPO technique, (c) ruthenium red method.Our observations concern the early period of the postembryonic development of the nervous system in oligochaetes. During this period neurons occupy fixed positions in the body the only observable change being the increase in volume of their perikaryons. Perikaryons of glial cells were located at some distance from neurons. Long cytoplasmic processes of glial cells tended to approach the neurons. The superimposed contours of glial cell processes designed from electron micrographs, taken at the same magnification, typical for five successive growth stages of the nervous system of Octolasium complanatum are shown in Fig. 1. Neuron is designed symbolically to facilitate the understanding of the kinetics of the growth process.

scholarly journals Interaction of phosphorylated Rab11-FIP2 with Eps15 regulates apical junction composition

2017 ◽  
Vol 28 (8) ◽  
pp. 1088-1100 ◽  
Author(s):  
Lynne A. Lapierre ◽  
Elizabeth H. Manning ◽  
Kenya M. Mitchell ◽  
Cathy M. Caldwell ◽  
James R. Goldenring
Keyword(s):  
Mdck Cells ◽  
Three Dimensional ◽  
3D Culture ◽  
Cyst Formation ◽  
Epithelial Polarity ◽  
Lateral Membrane ◽  
Low Calcium ◽  
Single Lumen ◽  
Apical Junctions ◽  
Temporal Localization

MARK2 regulates the establishment of polarity in Madin–Darby canine kidney (MDCK) cells in part through phosphorylation of serine 227 of Rab11-FIP2. We identified Eps15 as an interacting partner of phospho-S227-Rab11-FIP2 (pS227-FIP2). During recovery from low calcium, Eps15 localized to the lateral membrane before pS227-FIP2 arrival. Later in recovery, Eps15 and pS227-FIP2 colocalized at the lateral membrane. In MDCK cells expressing the pseudophosphorylated FIP2 mutant FIP2(S227E), during recovery from low calcium, Eps15 was trapped and never localized to the lateral membrane. Mutation of any of the three NPF domains within GFP-FIP2(S227E) rescued Eps15 localization at the lateral membrane and reestablished single-lumen cyst formation in GFP-FIP2(S227E)–expressing cells in three-dimensional (3D) culture. Whereas expression of GFP-FIP2(S227E) induced the loss of E-cadherin and occludin, mutation of any of the NPF domains of GFP-FIP2(S227E) reestablished both proteins at the apical junctions. Knockdown of Eps15 altered the spatial and temporal localization of pS227-FIP2 and also elicited formation of multiple lumens in MDCK 3D cysts. Thus an interaction of Eps15 and pS227-FIP2 at the appropriate time and location in polarizing cells is necessary for proper establishment of epithelial polarity.

scholarly journals A Novel Cysteine Protease Inhibitor of Naegleria fowleri That Is Specifically Expressed during Encystation and at Mature Cysts

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 388
Author(s):  
Hương Giang Lê ◽  
A-Jeong Ham ◽  
Jung-Mi Kang ◽  
Tuấn Cường Võ ◽  
Haung Naw ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Cysteine Protease ◽  
Expression Profiles ◽  
Critical Role ◽  
Cyst Formation ◽  
Cysteine Proteases ◽  
Cysteine Protease Inhibitor ◽  
Naegleria Fowleri ◽  
Nægleria Fowleri ◽  
Cystatin Family

Naegleria fowleri is a free-living amoeba that is ubiquitous in diverse natural environments. It causes a fatal brain infection in humans known as primary amoebic meningoencephalitis. Despite the medical importance of the parasitic disease, there is a great lack of knowledge about the biology and pathogenicity of N. fowleri. In this study, we identified and characterized a novel cysteine protease inhibitor of N. fowleri (NfCPI). NfCPI is a typical cysteine protease inhibitor belonging to the cystatin family with a Gln-Val-Val-Ala-Gly (QVVAG) motif, a characteristic motif conserved in the cystatin family of proteins. Bacterially expressed recombinant NfCPI has a dimeric structure and exhibits inhibitory activity against several cysteine proteases including cathespin Bs of N. fowleri at a broad range of pH values. Expression profiles of nfcpi revealed that the gene was highly expressed during encystation and cyst of the amoeba. Western blot and immunofluorescence assays also support its high level of expression in cysts. These findings collectively suggest that NfCPI may play a critical role in encystation or cyst formation of N. fowleri by regulating cysteine proteases that may mediate encystation or mature cyst formation of the amoeba. More comprehensive studies to investigate the roles of NfCPI in encystation and its target proteases are necessary to elucidate the regulatory mechanism and the biological significance of NfCPI.

scholarly journals Transcriptome and metabolome analyses of cold and darkness-induced pellicle cysts of Scrippsiella trochoidea

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xin Guo ◽  
Zhaohui Wang ◽  
Lei Liu ◽  
Yang Li
Keyword(s):  
Signal Transduction ◽  
Sexual Reproduction ◽  
Harmful Algal Bloom ◽  
Transcriptional Response ◽  
Tca Cycle ◽  
Adaptive Strategy ◽  
Cyst Formation ◽  
Metabolite Profile ◽  
Scrippsiella Trochoidea ◽  
Regulatory Processes

Abstract Background Dinoflagellates are a group of unicellular organisms that are a major component of aquatic eukaryotes and important contributors to marine primary production. Nevertheless, many dinoflagellates are considered harmful algal bloom (HAB) species due to their detrimental environmental and human health impacts. Cyst formation is widely perceived as an adaptive strategy of cyst-forming dinoflagellates in response to adverse environmental conditions. Dinoflagellate cysts play critical roles in bloom dynamics. However, our insight into the underlying molecular basis of encystment is still limited. To investigate the molecular processes regulating encystment in dinoflagellates, transcriptome and metabolome investigations were performed on cold and darkness-induced pellicle cysts of Scrippsiella trochoidea. Results No significant transcriptional response was observed at 2 h; however, massive transcriptome and metabolome reprogramming occurred at 5 h and in pellicle cysts. The gene-to-metabolite network demonstrated that the initial transformation from vegetative cells into pellicle cysts was highly energy demanding through the activation of catabolism, including glycolysis, β-oxidation, TCA cycle and oxidative phosphorylation, to cope with cold-darkness-induced stress. However, after transformation into pellicle cysts, the metabolism was greatly reduced, and various sugars, polyunsaturated fatty acids and amino acids accumulated to prolong survival. The identification of 56 differentially expressed genes (DEGs) related to signal transduction indicated that S. trochoidea received a cold-darkness signal that activated multiple signal transduction pathways, leading to encystment. The elevated expression of genes encoding enzymes involved in ROS stress suggested that pellicle cysts respond to increased oxidative stress. Several cell cycle-related genes were repressed. Intriguingly, 11 DEGs associated with sexual reproduction suggested that pellicle cysts (or some portion thereof) may be a product of sexual reproduction. Conclusions This study provides the first transcriptome and metabolome analyses conducted during the encystment of S. trochoidea, an event that requires complex regulatory mechanisms and impacts on population dynamics. The results reveal comprehensive molecular regulatory processes underlying life cycle regulation in dinoflagellates involving signal transduction, gene expression and metabolite profile, which will improve our ability to understand and monitor dinoflagellate blooms.

scholarly journals An Unusual Case of Meckel Diverticulitis Misdiagnosed as an Infected Urachal Cyst

Medicina ◽  
2021 ◽  
Vol 57 (5) ◽  
pp. 495
Author(s):  
Ioana Anca Stefanopol ◽  
Magdalena Miulescu ◽  
Liliana Baroiu ◽  
Aurelian-Dumitrache Anghele ◽  
Dumitru Marius Danila ◽  
...  
Keyword(s):  
Meckel’S Diverticulum ◽  
Surgical Excision ◽  
Cyst Formation ◽  
Meckel's Diverticulum ◽  
Urachal Cyst ◽  
Macroscopic Appearance ◽  
Surgical Interventions ◽  
Bladder Dome ◽  
Low Sensitivity ◽  
Tract Infections

Introduction: Meckel’s diverticulum (MD), a remnant of the omphaloenteric duct, is among the most frequent intestinal malformations. Another embryonic vestige is the urachus, which obliterates, becoming the median umbilical ligament; the failure of this process can lead to a urachal cyst formation. We present a case of Meckel diverticulitis misdiagnosed as an infected urachal cyst. Presentation of case: A 16-year-old girl presented with hypogastric pain, fever and vomiting. She had undergone an appendectomy 6 years prior and no digestive malformation had been documented. In the last 2 years, she had 3 events of urinary tract infections with Escherichia coli, and anabdominal ultrasound discovered a 28/21 mm hypoechogenic preperitoneal round tumor, anterosuperior to the bladder. We established the diagnosis of an infected urachal cyst, confirmed later by magnetic resonance imaging. Intraoperative, we found MD with necrotic diverticulitis attached to the bladder dome. Discussions: Meckel’s diverticulum and urachal cyst (UC) are embryonic remnants. Both conditions are usually asymptomatic, being incidentally discovered during imaging or surgery performed for other abdominal pathology. Imaging diagnosis is accurate for UC, but for MD they are low sensitivity and specificity. For UC treatment, there is a tendency to follow an algorithm related to age and symptoms, but there is no general consensus on whether to perform a routine resection of incidentally discovered MD. Conclusion: Preoperatory diagnosis of MD represents a challenge. We want to emphasize the necessity of a thorough inspection of the small bowel during all abdominal surgical interventions and MD surgical excision regardless of its macroscopic appearance. These two actions seem to be the best prophylaxis measures for MD complications and consequently to avoid emergency surgery, in which case more extensive surgical procedures on an unstable patient may be needed.

scholarly journals FLCN alteration drives metabolic reprogramming towards nucleotide synthesis and cyst formation in salivary gland

2020 ◽  
Vol 522 (4) ◽  
pp. 931-938
Author(s):  
Yasuhiro Isono ◽  
Mitsuko Furuya ◽  
Tatsu Kuwahara ◽  
Daisuke Sano ◽  
Kae Suzuki ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Cyst Formation ◽  
Metabolic Reprogramming ◽  
Nucleotide Synthesis
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