Morphogenesis of the tarsal tissue and the development of the intromittent palpal organs in the wolf-spider Lycosa chaperi (Simon) (Araneida: Lycosidae)

1971 ◽  
Vol 49 (3) ◽  
pp. 397-400 ◽  
Author(s):  
R. D. S. Bhatnagar ◽  
G. L. Sadana
Keyword(s):  
Wolf Spider ◽  
Postembryonic Development ◽  
Epidermal Cells ◽  
Developmental Sequence

In the males of Lycosa chaperi the apical epidermal cells of the pedipalpal tarsus develop into the 'palpal organs' during the final three instars of the postembryonic development. The developmental sequence precludes any role of the pretarsal claw in the process, thus discounting an earlier hypothesis that the palpal organ is a hypertrophied claw.

scholarly journals The Role of Catalase-Peroxidase Secreted by Magnaporthe oryzae During Early Infection of Rice Cells

2011 ◽  
Vol 24 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Shigeru Tanabe ◽  
Naoko Ishii-Minami ◽  
Ken-Ichiro Saitoh ◽  
Yuko Otake ◽  
Hanae Kaku ◽  
...  
Keyword(s):  
Culture Filtrate ◽  
Magnaporthe Oryzae ◽  
Early Stage ◽  
Major Gene ◽  
Leaf Sheath ◽  
Epidermal Cells ◽  
Amino Acid Sequences ◽  
Conidial Suspension ◽  
Catalase Peroxidase

The biological role of a secretory catalase of the rice blast fungus Magnaporthe oryzae was studied. The internal amino acid sequences of the partially purified catalase in the culture filtrate enabled us to identify its encoding gene as a catalase-peroxidase gene, CPXB, among four putative genes for catalase or catalase-peroxidase in M. oryzae. Knockout of the gene drastically reduced the level of catalase activity in the culture filtrate and supernatant of conidial suspension (SCS), and increased the sensitivity to exogenously added H2O2 compared with control strains, suggesting that CPXB is the major gene encoding the secretory catalase and confers resistance to H2O2 in hyphae. In the mutant, the rate of appressoria that induced accumulation of H2O2 in epidermal cells of the leaf sheath increased and infection at early stages was delayed; however, the formation of lesions in the leaf blade was not affected compared with the control strain. These phenotypes were complimented by reintroducing the putative coding regions of CPXB driven by a constitutive promoter. These results suggest that CPXB plays a role in fungal defense against H2O2 accumulated in epidermal cells of rice at the early stage of infection but not in pathogenicity of M. oryzae.

Histological Studies on the Genus Fucus

1968 ◽  
Vol 3 (1) ◽  
pp. 1-16
Author(s):  
MARGARET E. MCCULLY
Keyword(s):  
Inorganic Carbon ◽  
Alginic Acid ◽  
Light And Electron Microscopy ◽  
Epidermal Cells ◽  
Membrane Interface ◽  
Histological Studies ◽  
Basal Nuclei ◽  
Golgi System ◽  
Intracellular Volume

The fine structure of the epidermal cells of the vegetative Fucus thallus has been examined in material fixed with acrolein. These cells are highly polarized, with basal nuclei and chloroplasts, a hypertrophied perinuclear Golgi system, and a much convoluted wall/plasma membrane interface. Much of the intracellular volume is occupied by single membrane-bounded vesicles containing alginic acid, fucoidin and polyphenols. The chloroplasts were examined by light and electron microscopy and shown to contain structured inclusions not previously described in Fucus plastids. It is suggested on the basis of their morphology that the epidermal cells may be specialized for the absorption of inorganic carbon and sulphate from the outside of the plant and for the secretion of alginic acid, fucoidin and polyphenols. The possible role of these cells in the prevention of desiccation and in osmoregulation is discussed.

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 A therapy programme for pre-school language impaired children

1976 ◽  
Vol 23 (1) ◽  
Author(s):  
Linda Narun
Keyword(s):  
Language Learning ◽  
Discrimination Learning ◽  
Syntactic Analysis ◽  
Developmental Sequence ◽  
Language Impaired ◽  
Auxiliary Verbs ◽  
Impaired Children ◽  
Therapy Programme

This study aimed to establish effective language programmes for pre-school language impaired children based on psycholinguistic principles. Eight language-impaired children 6 males and 2 females between the ages of 3 and 6 years, were the subjects. Language samples were transcribed and subjected to syntactic analysis; semantic aspects were also considered and programmes developed for each subject, based on the information obtained from the language analyses. A developmental sequence was adopted as the basis for therapy A 'slot-method' was used in which language was taught as rule-operated behaviour Principles of discrimination learning were adopted for teaching some aspects of grammar. Auxiliary verbs are reported in detail as this was the most universal error and difficult to teach. The role of imitation in language learning and therapy is discussed.

scholarly journals Epidermal autonomous VEGFA/Flt1/Nrp1 functions mediate psoriasis-like disease

2020 ◽  
Vol 6 (2) ◽  
pp. eaax5849 ◽  
Author(s):  
Farida Benhadou ◽  
Elisabeth Glitzner ◽  
Audrey Brisebarre ◽  
Benjamin Swedlund ◽  
Yura Song ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Skin Disorder ◽  
Inflammatory Cells ◽  
Epidermal Cells ◽  
Autonomous Function ◽  
Conditional Deletion ◽  
Gene Regulatory ◽  
Chronic Skin ◽  
Chromatin Profiling

Psoriasis is a common chronic skin disorder characterized by keratinocyte hyperproliferation with altered differentiation accompanied by inflammation and increased angiogenesis. It remains unclear whether the first events that initiate psoriasis development occur in keratinocytes or inflammatory cells. Here, using different psoriasis mouse models, we showed that conditional deletion of Flt1 or Nrp1 in epidermal cells inhibited psoriasis mediated by Vegfa overexpression or c-Jun/JunB deletion. Administration of anti-Nrp1 antibody reverted the psoriasis phenotype. Using transcriptional and chromatin profiling of epidermal cells following Vegfa overexpression together with Flt1 or Nrp1 deletion, we identified the gene regulatory network regulated by Vegfa/Nrp1/Flt1 during psoriasis development and uncovered a key role of Fosl1 in regulating the chromatin remodeling mediated by Vegfa overexpression in keratinocytes. In conclusion, our study identifies an epidermal autonomous function of Vegfa/Nrp1/Flt1 that mediates psoriatic-like disease and demonstrates the clinical relevance of blocking Vegfa/Nrp1/Flt1 axis in psoriasis.

scholarly journals The innovation of the final moult and the origin of insect metamorphosis

2019 ◽  
Vol 374 (1783) ◽  
pp. 20180415 ◽  
Author(s):  
Xavier Belles
Keyword(s):  
Common Ancestor ◽  
Adult Stage ◽  
Postembryonic Development ◽  
Prothoracic Gland ◽  
Last Common Ancestor ◽  
Early Devonian ◽  
Final Moult ◽  
Insect Metamorphosis ◽  
Complete Metamorphosis

The three modes of insect postembryonic development are ametaboly, hemimetaboly and holometaboly, the latter being considered the only significant metamorphosis mode. However, the emergence of hemimetaboly, with the genuine innovation of the final moult, represents the origin of insect metamorphosis and a necessary step in the evolution of holometaboly. Hemimetaboly derives from ametaboly and might have appeared as a consequence of wing emergence in Pterygota, in the early Devonian. In extant insects, the final moult is mainly achieved through the degeneration of the prothoracic gland (PG), after the formation of the winged and reproductively competent adult stage. Metamorphosis, including the formation of the mature wings and the degeneration of the PG, is regulated by the MEKRE93 pathway, through which juvenile hormone precludes the adult morphogenesis by repressing the expression of transcription factor E93, which triggers this change. The MEKRE93 pathway appears conserved in extant metamorphosing insects, which suggest that this pathway was operative in the Pterygota last common ancestor. We propose that the final moult, and the consequent hemimetabolan metamorphosis, is a monophyletic innovation and that the role of E93 as a promoter of wing formation and the degeneration of the PG was mechanistically crucial for their emergence. This article is part of the theme issue ‘The evolution of complete metamorphosis’.

scholarly journals LncRNA MEG3 influences the proliferation and apoptosis of psoriasis epidermal cells by targeting miR-21/caspase-8

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Hai-Yan Jia ◽  
Kai Zhang ◽  
Wen-Jing Lu ◽  
Gui-Wen Xu ◽  
Jian-Fen Zhang ◽  
...  
Keyword(s):  
Binding Site ◽  
Cell Model ◽  
Mrna Level ◽  
Epidermal Cells ◽  
Luciferase Reporter ◽  
Psoriatic Skin ◽  
Caspase 8 ◽  
Proliferation And Apoptosis

Abstract Background It was reported that microRNA-21(miR-21) was differentially expressed in the keratinocytes of psoriasis patients, and it may influence the apoptosis and proliferation of cells. The role of lncRNA maternally expressed gene3 (MEG3), a competing endogenous RNAs of miR-21, in the progression of psoriasis remains unclear. We aimed to unfold the influence of MEG3 and miR-21 on the proliferation and apoptosis of psoriasis epidermal cells. Methods 50μg/L TNF-α was used to treat HaCaTs and NHEKs cells for 24 h, and then different experiments were conducted. qRT-PCR were applied for measuring the mRNA level of MEG3, miR-2, and caspase-8, and the protein expression of caspase-8 was measured with western blotting. Flow cytometry was used for assessing apoptosis. Cell proliferation was detected using MTT and colony formation assays. Dual luciferase reporter assay was applied for confirming the binding site between MEG3 and miR-21, miR-21 and Caspase-8. Results A cell model for in vitro studying the role of MEG3 in psoriasis pathophysiology was established using HaCaT and HHEKs. MEG3 was significantly down-regulated in HaCaT, HHEKs, and psoriatic skin samples. MEG3 inhibits proliferation and promotes apoptosis of Activated-HaCaT (Act-HaCaT) and Activated-HHEKs (Act- HHEK) by regulating miR-21, and the binding site between MEG3 and miR-21 was identified. We also found that miR-21 could inhibit the level of caspase-8 and identified the binding site between caspase-8 and miR-21. Some down-stream proteins of caspase-8, Cleaved caspase-8, cytc, and apaf-1 were regulated by miR-21 and MEG3. Conclusion MEG3/miR-21 axis may regulate the expression of caspase-8, and further influence the proliferation and apoptosis of psoriasis keratinocyte, Act-HaCaT and Act- HHEK. Therefore, our findings may provide a new thought for the study of pathogenesis and treatment of psoriasis.

scholarly journals Some developmental aspects of sentence processing and memory

1978 ◽  
Vol 5 (1) ◽  
pp. 113-129 ◽  
Author(s):  
Lorraine K. Tyler ◽  
William Marslen-Wilson
Keyword(s):  
Sentence Processing ◽  
Main Type ◽  
Memory Task ◽  
Memory Effects ◽  
Main Clause ◽  
Developmental Sequence

ABSTRACTThree groups of children, aged 5, 7 and 11 years, were tested in a clause-memory task, in order to investigate the role of syntactic and semantic factors in children's recall and processing of spoken continuous prose. The children listened to a story, which was interrupted at intervals during which they were asked to repeat verbatim the last sentence they heard. The test-sentences always consisted of two clauses: either of the main–main type, or of the main–subordinate or subordinate–main types. The prose material was also either normal prose, or semantically uninterpretable but syntactically normal prose. The results suggest a developmental sequence in which the youngest group's performance is dominated by semantic factors. They do not show the adult clause-memory effects, their recall is dominated by the main clause, and their recall of normal prose is not clausally segmented. The two older groups' performance more closely approximates that of adults.

Role of Pin1 in UVA-induced cell proliferation and malignant transformation in epidermal cells

2011 ◽  
Vol 410 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Chang Yeob Han ◽  
Tran Thi Hien ◽  
Sung Chul Lim ◽  
Keon Wook Kang
Keyword(s):  
Cell Proliferation ◽  
Malignant Transformation ◽  
Epidermal Cells
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