Cellular reactions of the field cricket (Gryllus pennsylvanicus (Burmeister)) to Turgida turgida (Rudolphi, 1819) (Nematoda: Physalopteroidea)

1983 ◽  
Vol 61 (9) ◽  
pp. 2143-2146 ◽  
Author(s):  
J. B. Gray ◽  
R. C. Anderson

Cellular reactions to infections of Turgida turgida (Rudolphi, 1819) in field crickets (Gryllus pennsylvanicus (Burmeister) (=Acheta pennsylvanicus Burmeister)) were studied. Most larvae reached the epithelial cells of the ileum. These larvae caused little cellular destruction or haemocytic response until 18 h after infection. Syncytia of epithelial cell origin had formed around larvae by 28 h after infection. Initially, each syncytium was surrounded by haemocytes and later, by a wall with two well-defined layers. The epithelial layer of the alimentary tract had regenerated beneath the capsule by 48 days. Occasionally larvae penetrated directly into the haemocoel and were surrounded by haemocytes and(or) became melanized.

Author(s):  
V. F. Allison ◽  
G. C. Fink ◽  
G. W. Cearley

It is well known that epithelial hyperplasia (benign hypertrophy) is common in the aging prostate of dogs and man. In contrast, little evidence is available for abnormal epithelial cell growth in seminal vesicles of aging animals. Recently, enlarged seminal vesicles were reported in senescent mice, however, that enlargement resulted from increased storage of secretion in the lumen and occurred concomitant to epithelial hypoplasia in that species.The present study is concerned with electron microscopic observations of changes occurring in the pseudostratified epithelium of the seminal vescles of aging rats. Special attention is given to certain non-epithelial cells which have entered the epithelial layer.


2000 ◽  
Vol 78 (1) ◽  
pp. 140-143 ◽  
Author(s):  
David A Gray ◽  
William H Cade

The evolutionary theory of aging proposes that senescence is related to decreased selection against deleterious mutations acting late in life. Senescence, i.e., an increase in intrinsic mortality with age, should reflect levels of extrinsic mortality early in life. We tested these predictions using two species of field cricket, Gryllus integer and Gryllus pennsylvanicus. Gryllus integer males are host to a sex-biased parasitoid fly, which orients to the male calling song. As a result, males have reduced life expectancy compared with females in the field. In contrast, G. pennsylvanicus males and females appear to have similar life expectancies in the wild. Thus, we predicted that there would be a significant species × sex interaction, with G. integer males having the shortest life-span. In two replicates, we found that males of both species died at a significantly younger age than females. However, no evidence of a species × sex interaction was found: in the first replicate, G. integer males died earliest, in the second replicate, G. pennsylvanicus males died earliest.


Author(s):  
D.G. Osborne ◽  
L.J. McCormack ◽  
M.O. Magnusson ◽  
W.S. Kiser

During a project in which regenerative changes were studied in autotransplanted canine kidneys, intranuclear crystals were seen in a small number of tubular epithelial cells. These crystalline structures were seen in the control specimens and also in regenerating specimens; the main differences being in size and number of them. The control specimens showed a few tubular epithelial cell nuclei almost completely occupied by large crystals that were not membrane bound. Subsequent follow-up biopsies of the same kidneys contained similar intranuclear crystals but of a much smaller size. Some of these nuclei contained several small crystals. The small crystals occurred at one week following transplantation and were seen even four weeks following transplantation. As time passed, the small crystals appeared to fuse to form larger crystals.


Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 609-621
Author(s):  
Laura A Katz ◽  
Richard G Harrison

Two species of crickets, Gryllus veletis and G. pennsylvanicus, share six electrophoretic mobility classes for the enzyme phosphoglucose isomerase (PGI), despite evidence from other genetic markers that the two species are not closely related within eastern North American field crickets. Moreover, the frequencies of the two most common PGI electrophoretic classes (PGI-100 and PGI-65) covary in sympatric populations of these species in the eastern United States, suggesting that PGI may be subject to trans-specific balancing selection. To determine the molecular basis of the electrophoretic variation, we characterized the DNA sequence of the Pgi gene from 29 crickets (15 G. veletis and 14 G. pennsylvanicus). Amino acid substitutions that distinguish the electrophoretic classes are not the same in the two species, and there is no evidence that specific replacement substitutions represent trans-specific polymorphism. In particular, the amino acids that diagnose the PGI-65 allele relative to the PGI-100 allele differ both between G. veletis and G. pennsylvanicus and within G. pennsylvanicus. The heterogeneity among electrophoretic classes that covary in sympatric populations coupled with analysis of patterns of nucleotide variation suggest that Pgi is not evolving neutrally. Instead, the data are consistent with balancing selection operating on an emergent property of the PGI protein.


1993 ◽  
Vol 264 (1) ◽  
pp. F149-F157 ◽  
Author(s):  
J. Gailit ◽  
D. Colflesh ◽  
I. Rabiner ◽  
J. Simone ◽  
M. S. Goligorsky

Tubular obstruction by detached renal tubular epithelial cells is a major cause of oliguria in acute renal failure. Viable renal tubular cells can be recovered from urine of patients with acute tubular necrosis, suggesting a possible defect in cell adhesion to the basement membrane. To study this process of epithelial cell desquamation in vitro, we investigated the effect of nonlethal oxidative stress on the integrin adhesion receptors of the primate kidney epithelial cell line BS-C-1. Morphological and functional studies of cell adhesion properties included the following: interference reflection microscopy, intravital confocal microscopy and immunocytochemistry, flow cytometric analysis of integrin receptor abundance, and cell-matrix attachment assay. High levels of the integrin subunits alpha 3, alpha v, and beta 1 were detected on the cell surface by fluorescence-activated cell sorting (FACS) analysis, as well as lower levels of alpha 1, alpha 2, alpha 4, alpha 5, alpha 6, and beta 3. Exposure of BS-C-1 cells to nonlethal oxidative stress resulted in the disruption of focal contacts, disappearance of talin from the basal cell surface, and in the redistribution of integrin alpha 3-subunits from predominantly basal location to the apical cell surface. As measured in a quantitative cell attachment assay, oxidative stress decreased BS-C-1 cell adhesion to type IV collagen, laminin, fibronectin, and vitronectin. Defective adhesion was not associated with a loss of alpha 3-, alpha 4-, or alpha v-integrin subunits from the cell surface.(ABSTRACT TRUNCATED AT 250 WORDS)


2011 ◽  
Vol 301 (2) ◽  
pp. C522-C529 ◽  
Author(s):  
Justine Elliott ◽  
Nadezhda N. Zheleznova ◽  
Patricia D. Wilson

c-Src is a non-receptor tyrosine kinase whose activity is induced by phosphorylation at Y418 and translocation from the cytoplasm to the cell membrane. Increased activity of c-Src has been associated with cell proliferation, matrix adhesion, motility, and apoptosis in tumors. Immunohistochemistry suggested that activated (pY418)-Src activity is increased in cyst-lining autosomal dominant polycystic kidney disease (ADPKD) epithelial cells in human and mouse ADPKD. Western blot analysis showed that SKI-606 (Wyeth) is a specific inhibitor of pY418-Src without demonstrable effects on epidermal growth factor receptor or ErbB2 activity in renal epithelia. In vitro studies on mouse inner medullary collecting duct (mIMCD) cells and human ADPKD cyst-lining epithelial cells showed that SKI-606 inhibited epithelial cell proliferation over a 24-h time frame. In addition, SKI-606 treatment caused a striking statistically significant decrease in adhesion of mIMCD and human ADPKD to extracellular collagen matrix. Retained viability of unattached cells was consistent with a primary effect on epithelial cell anchorage dependence mediated by the loss of extracellular matrix (ECM)-attachment due to α2β1-integrin function. SKI-606-mediated attenuation of the human ADPKD hyperproliferative and hyper-ECM-adhesive epithelial cell phenotype in vitro was paralleled by retardation of the renal cystic phenotype of Pkd1 orthologous ADPKD heterozygous mice in vivo. This suggests that SKI-606 has dual effects on cystic epithelial cell proliferation and ECM adhesion and may have therapeutic potential for ADPKD patients.


1958 ◽  
Vol 36 (2) ◽  
pp. 139-151 ◽  
Author(s):  
R. S. Bigelow

Progeny of northern spring field cricket adults lay non-diapause eggs, undergo nymphal diapause, and overwinter as nymphs. Progeny of northern fall adults lay diapause eggs, do not undergo nymphal diapause, and overwinter as eggs. The two populations cannot interbreed freely in the field owing to a temporal difference in breeding seasons; they did not interbreed in the laboratory. Rearing experiments show that the developmental differences are genetically based rather than environmentally conditioned, and it is, therefore, unlikely that hybrids would be viable even if they were produced in the field. Consequently these two populations behave as good species. Field crickets from Virginia developed much more rapidly than did spring crickets from Quebec. Quebec spring males and Virginia females produced hybrids with developmental rates intermediate between those of their parents. More female than male hybrids were produced, and the females developed more rapidly than did male hybrids. Offspring were produced by hybrid females and Quebec spring males, but not by hybrid females and Virginia males. Partial, but incomplete reproductive isolation exists between Quebec and Virginia field crickets. A possible mechanism of sympatric speciation in insects is discussed.


2008 ◽  
Vol 22 (12) ◽  
pp. 2677-2688 ◽  
Author(s):  
Paul G. Tiffen ◽  
Nader Omidvar ◽  
Nuria Marquez-Almuina ◽  
Dawn Croston ◽  
Christine J. Watson ◽  
...  

Abstract Recent studies in breast cancer cell lines have shown that oncostatin M (OSM) not only inhibits proliferation but also promotes cell detachment and enhances cell motility. In this study, we have looked at the role of OSM signaling in nontransformed mouse mammary epithelial cells in vitro using the KIM-2 mammary epithelial cell line and in vivo using OSM receptor (OSMR)-deficient mice. OSM and its receptor were up-regulated approximately 2 d after the onset of postlactational mammary regression, in response to leukemia inhibitory factor (LIF)-induced signal transducer and activator of transcription-3 (STAT3). This resulted in sustained STAT3 activity, increased epithelial apoptosis, and enhanced clearance of epithelial structures during the remodeling phase of mammary involution. Concurrently, OSM signaling precipitated the dephosphorylation of STAT5 and repressed expression of the milk protein genes β-casein and whey acidic protein (WAP). Similarly, during pregnancy, OSM signaling suppressed β-casein and WAP gene expression. In vitro, OSM but not LIF persistently down-regulated phosphorylated (p)-STAT5, even in the continued presence of prolactin. OSM also promoted the expression of metalloproteinases MMP3, MMP12, and MMP14, which, in vitro, were responsible for OSM-specific apoptosis. Thus, the sequential activation of IL-6-related cytokines during mammary involution culminates in an OSM-dependent repression of epithelial-specific gene expression and the potentiation of epithelial cell extinction mediated, at least in part, by the reciprocal regulation of p-STAT5 and p-STAT3.


2005 ◽  
Vol 54 (5) ◽  
pp. 497-504 ◽  
Author(s):  
Joseph Richardson ◽  
Justin Corey Craighead ◽  
Sam Linsen Cao ◽  
Martin Handfield

Actinobacillus actinomycetemcomitans is a facultatively intracellular pathogen and the aetiological agent of localized aggressive periodontitis. Screening of the genome of A. actinomycetemcomitans for in vivo-induced antigen determinants previously demonstrated that the proteome of this organism differs in laboratory culture compared with conditions found during active infection. The aim of the present study was to determine whether the bacterial gene expression pattern inferred with in vivo-induced antigen technology (IVIAT) in human infections was consistent with the gene expression pattern occurring upon epithelial cell association. To this end, a real-time PCR method was developed and used to quantify absolute and relative bacterial gene expression of A. actinomycetemcomitans grown extra- and intracellularly in two human epithelial cell lines (HeLa and IHGK). The amount of template used in the assay was normalized using the total count of viable bacteria (c.f.u.) as a reference point and performed in duplicate in at least two independent experiments. Controls for this experiment included 16S rRNA and gapdh. Transcription of all eight ORFs tested increased significantly (P < 0.05) in HeLa and IHGK cells compared with bacteria grown extracellularly. The concurrence of gene expression patterns found in the two models suggests that these epithelial cells are valid in vitro models of infection for the genes tested. IVIAT is an experimental platform that can be used as a validation tool to assess the reliability of animal and other models of infection and is applicable to most pathogens.


2002 ◽  
Vol 361 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Silvia GINÉS ◽  
Marta MARIÑO ◽  
Josefa MALLOL ◽  
Enric I. CANELA ◽  
Chikao MORIMOTO ◽  
...  

The extra-enzymic function of cell-surface adenosine deaminase (ADA), an enzyme mainly localized in the cytosol but also found on the cell surface of monocytes, B cells and T cells, has lately been the subject of numerous studies. Cell-surface ADA is able to transduce co-stimulatory signals in T cells via its interaction with CD26, an integral membrane protein that acts as ADA-binding protein. The aim of the present study was to explore whether ADA—CD26 interaction plays a role in the adhesion of lymphocyte cells to human epithelial cells. To meet this aim, different lymphocyte cell lines (Jurkat and CEM T) expressing endogenous, or overexpressing human, CD26 protein were tested in adhesion assays to monolayers of colon adenocarcinoma human epithelial cells, Caco-2, which express high levels of cell-surface ADA. Interestingly, the adhesion of Jurkat and CEM T cells to a monolayer of Caco-2 cells was greatly dependent on CD26. An increase by 50% in the cell-to-cell adhesion was found in cells containing higher levels of CD26. Incubation with an anti-CD26 antibody raised against the ADA-binding site or with exogenous ADA resulted in a significant reduction (50–70%) of T-cell adhesion to monolayers of epithelial cells. The role of ADA—CD26 interaction in the lymphocyte—epithelial cell adhesion appears to be mediated by CD26 molecules that are not interacting with endogenous ADA (ADA-free CD26), since SKW6.4 (B cells) that express more cell-surface ADA showed lower adhesion than T cells. Adhesion stimulated by CD26 and ADA is mediated by T cell lymphocyte function-associated antigen. A role for ADA—CD26 interaction in cell-to-cell adhesion was confirmed further in integrin activation assays. FACS analysis revealed a higher expression of activated integrins on T cell lines in the presence of increasing amounts of exogenous ADA. Taken together, these results suggest that the ADA—CD26 interaction on the cell surface has a role in lymphocyte—epithelial cell adhesion.


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