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Hemocyte types and total and differential counts in unparasitized and parasitized Anastrepha obliqua (Diptera, Tephritidae) larvae

SILVA, J. E. B.; BOLELI, I. C.; SIMÕES, Z. L. P.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: 689-699
ENG
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Os tipos de hemócitos e as contagens total e diferencial foram estudados em larvas parasitadas e não parasitadas de Anastrepha obliqua pertencentes ao início e ao final da terceira fase. em ambas as fases do desenvolvimento, tanto em larvas parasitadas quanto nas não parasitadas, foram observados pró-hemócitos, plasmatócitos, granulócitos, adipo-hemócitos, esferulócitos e oenocitóides. A presença de divisões mitóticas indica os pró-hemócitos como células-tronco. Pró-hemócitos, plasmatócitos e granulócitos são as células mais numerosas na hemolinfa de A. obliqua. Foi observada diferença no número total de hemócitos entre larvas parasitadas e não parasitadas apenas no final da terceira fase.; The hemocyte types, in addition to total and differential hemocyte counts were studied in parasitized and unparasitized Anastrepha obliqua larvae at the beginning and at the end of the third instar. In both developmental phases, in parasitized and unparasitized larvae, prohemocytes, plasmatocytes, granulocytes, adipohemocytes, spherulocytes and oenocytoids cells were observed. Mitotic figures indicate prohemocytes as stem cells. Prohemocytes, plasmatocytes and granulocytes are the most numerous cells in the hemolymph of A. obliqua. Difference in the total number of hemocytes was observed between unparasitized and parasitized larvae at the end of the third instar...

Estudo morfológico e quantitativo dos hemócitos em larvas de Diatraea saccharalis (Fabricius) (Lepidoptera, Pyralidae)

Bombonato, Maria T. Siqueira; Gregório, Elisa A
Fonte: Sociedade Brasileira de Zoologia Publicador: Sociedade Brasileira de Zoologia
Tipo: Artigo de Revista Científica Formato: 867-879
POR
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Hemocytes of Diatraea saccharalis larvae aging from 13 to 26 days old were morphological and quantitatively characterized by phase contrast microscopy. Six hemocyte types were described and identified as: prohemocytes (PR), plasmatocytes (PL), granulocytes (GR), oenocytoides (OE). spherulocytes (SP) and verm cells (VE). The total hemocyte counts showed no significant difference in the number of these cells along the normal development of the larvae. However, the relative number of different circulating hemocyte types fluctuated, and it could be expressed as: PL > GR > SP> PR > VE > OE in larvae up to 14 days old; and as: GR > SP > PL > VE > OE > PR in those older than 24 days.

Hemócitos fagocitários em larvas de Diatraea saccharalis (Fabricius) (Lepidoptera, Pyralidae)

Falleiros, Angela M.F; Gregório, Elisa A
Fonte: Sociedade Brasileira de Zoologia Publicador: Sociedade Brasileira de Zoologia
Tipo: Artigo de Revista Científica Formato: 751-758
POR
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); The ultrastructural observation of the hemocytes of D. saccharalis larvae showed different hemocyte tvpes in various stage of interaction with microorganisms, which were interpreted as bacteria. The microorganisms were observed either free in the hemolymph or into the insect hemocytes. The bacteria were detected mostly into lhe granulocytes and plasmatocytes: the spherule cells and the oenocytoids also presented intracytoplasmic microorganisms, but less frequently. The fagocytic capacity of the different hemocyte tvpes is discussed.

Analysis of signalling pathways required for hemocyte navigation in Drosphila

Brandão, Ana Sofia da Silva Pereira
Fonte: Universidade de Lisboa Publicador: Universidade de Lisboa
Tipo: Dissertação de Mestrado
Publicado em //2011 ENG
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27.5%
Tese de mestrado. Biologia (Biologia Molecular e Genética). Universidade de Lisboa, Faculdade de Ciências, 2011; A migração celular é um fenómeno fundamental e altamente regulado, que desempenha um papel activo numa grande variedade de processos biológicos. Por exemplo, é essencial para os processos de gastrulação e organogénese durante o desenvolvimento embrionário e, também, para o estabelecimento e manutenção da homeostasia do organismo durante a vida adulta, onde participa na reparação de feridas e na migração de células imunitárias para locais de inflamação. Falhas nos mecanismos de migração celular podem originar diversas patologias, tais como inflamações crónicas, defeitos congénitos e metastização de tumores. Os processos que permitem a migração celular despertam, por isso, grande interesse do ponto de vista terapêutico. O mecanismo de migração celular direccionada, também designado por quimiotaxia, tem sido principalmente analisado através de estudos em cultura de células imunitárias de mamífero. Estes estudos identificaram vários estímulos quimiotácticos, receptores celulares e vias de sinalização essenciais para a migração celular. Alguns destes estímulos quimiotácticos são compostos por moléculas difusíveis designadas por quimiocinas. Estas moléculas são reconhecidas por receptores que se encontram à superfície dos leucócitos...

The hemocytes of Panstrogyllus Megistus (Hemiptera: Reduviidae)

Barracco,Margherita Anna; Oliveira,Rozemary de; Schlemper Junior,Bruno
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/1987 EN
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27.32%
Five hemocyte types were identified in the hemolymph of Panstrongylus megistus by phase contrast and common light microscopy using some histochemical methods. These are: Prohemocytes, small cells presenting a great nucleus/cytoplasm ratio; Plasmatocytes, the most numerous hemocytes, are polymorphic cells mainly characterized by a large amount of lysosomes; Granulocytes, hemocytes very similar to plasmatocytes which contain cytoplasmic granules and are especially rich in polysaccharides; Oenocytoids, cells presenting a small nucleus and a thick cytoplasm; they show many small round vacuoles when observed in Giemsa smears and many cytoplasmic granules under phase microscopy; Adipohemocytes, very large hemocytes, presenting many fat droplet inclusions which could correspond to free fat bodies which entered the hemolymph. Only prohemocytes and plasmatocytes can be clearly classified; all the other hemocyte types have a more ambiguous classification.

Hemócitos fagocitários em larvas de Diatraea saccharalis (Fabricius) (Lepidoptera, Pyralidae)

Falleiros,Angela M.F; Gregório,Elisa A
Fonte: Sociedade Brasileira de Zoologia Publicador: Sociedade Brasileira de Zoologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/1995 PT
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27.32%
The ultrastructural observation of the hemocytes of D. saccharalis larvae showed different hemocyte tvpes in various stage of interaction with microorganisms, which were interpreted as bacteria. The microorganisms were observed either free in the hemolymph or into the insect hemocytes. The bacteria were detected mostly into lhe granulocytes and plasmatocytes: the spherule cells and the oenocytoids also presented intracytoplasmic microorganisms, but less frequently. The fagocytic capacity of the different hemocyte tvpes is discussed.

Estudo morfológico e quantitativo dos hemócitos em larvas de Diatraea saccharalis (Fabricius) (Lepidoptera, Pyralidae)

Bombonato,Maria T. Siqueira; Gregório,Elisa A
Fonte: Sociedade Brasileira de Zoologia Publicador: Sociedade Brasileira de Zoologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/1995 PT
Relevância na Pesquisa
27.62%
Hemocytes of Diatraea saccharalis larvae aging from 13 to 26 days old were morphological and quantitatively characterized by phase contrast microscopy. Six hemocyte types were described and identified as: prohemocytes (PR), plasmatocytes (PL), granulocytes (GR), oenocytoides (OE). spherulocytes (SP) and verm cells (VE). The total hemocyte counts showed no significant difference in the number of these cells along the normal development of the larvae. However, the relative number of different circulating hemocyte types fluctuated, and it could be expressed as: PL > GR > SP> PR > VE > OE in larvae up to 14 days old; and as: GR > SP > PL > VE > OE > PR in those older than 24 days.

Hemocyte types and total and differential counts in unparasitized and parasitized Anastrepha obliqua (Diptera, Tephritidae) larvae

SILVA,J. E. B.; BOLELI,I. C.; SIMÕES,Z. L. P.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2002 EN
Relevância na Pesquisa
27.32%
The hemocyte types, in addition to total and differential hemocyte counts were studied in parasitized and unparasitized Anastrepha obliqua larvae at the beginning and at the end of the third instar. In both developmental phases, in parasitized and unparasitized larvae, prohemocytes, plasmatocytes, granulocytes, adipohemocytes, spherulocytes and oenocytoids cells were observed. Mitotic figures indicate prohemocytes as stem cells. Prohemocytes, plasmatocytes and granulocytes are the most numerous cells in the hemolymph of A. obliqua. Difference in the total number of hemocytes was observed between unparasitized and parasitized larvae at the end of the third instar, but not at the beginning.

Genetic analysis of contributions of dorsal group and JAK-Stat92E pathway genes to larval hemocyte concentration and the egg encapsulation response in Drosophila.

Sorrentino, Richard Paul; Melk, Jonathan P; Govind, Shubha
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /03/2004 EN
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Drosophila larvae defend themselves against parasitoid wasps by completely surrounding the egg with layers of specialized hemocytes called lamellocytes. Similar capsules of lamellocytes, called melanotic capsules, are also formed around "self" tissues in larvae carrying gain-of-function mutations in Toll and hopscotch. Constitutive differentiation of lamellocytes in larvae carrying these mutations is accompanied by high concentrations of plasmatocytes, the major hemocyte class in uninfected control larvae. The relative contributions of hemocyte concentration vs. lamellocyte differentiation to wasp egg encapsulation are not known. To address this question, we used Leptopilina boulardi to infect more than a dozen strains of host larvae harboring a wide range of hemocyte densities. We report a significant correlation between hemocyte concentration and encapsulation capacity among wild-type larvae and larvae heterozygous for mutations in the Hopscotch-Stat92E and Toll-Dorsal pathways. Larvae carrying loss-of-function mutations in Hopscotch, Stat92E, or dorsal group genes exhibit significant reduction in encapsulation capacity. Larvae carrying loss-of-function mutations in dorsal group genes (including Toll and tube) have reduced hemocyte concentrations...

A Misexpression Screen to Identify Regulators of Drosophila Larval Hemocyte Development

Stofanko, Martin; Kwon, So Yeon; Badenhorst, Paul
Fonte: Genetics Society of America Publicador: Genetics Society of America
Tipo: Artigo de Revista Científica
Publicado em /09/2008 EN
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In Drosophila, defense against foreign pathogens is mediated by an effective innate immune system, the cellular arm of which is composed of circulating hemocytes that engulf bacteria and encapsulate larger foreign particles. Three hemocyte types occur: plasmatocytes, crystal cells, and lamellocytes. The most abundant larval hemocyte type is the plasmatocyte, which is responsible for phagocytosis and is present either in circulation or in adherent sessile domains under the larval cuticle. The mechanisms controlling differentiation of plasmatocytes and their migration toward these sessile compartments are unclear. To address these questions we have conducted a misexpression screen using the plasmatocyte-expressed GAL4 driver Peroxidasin-GAL4 (Pxn-GAL4) and existing enhancer-promoter (EP) and EP yellow (EY) transposon libraries to systematically misexpress ∼20% of Drosophila genes in larval hemocytes. The Pxn-GAL4 strain also contains a UAS-GFP reporter enabling hemocyte phenotypes to be visualized in the semitransparent larvae. Among 3412 insertions screened we uncovered 101 candidate hemocyte regulators. Some of these are known to control hemocyte development, but the majority either have no characterized function or are proteins of known function not previously implicated in hemocyte development. We have further analyzed three candidate genes for changes in hemocyte morphology...

A Novel Viral Responsive Protein Is Involved in Hemocyte Homeostasis in the Black Tiger Shrimp, Penaeus monodon*

Prapavorarat, Adisak; Vatanavicharn, Tipachai; Söderhäll, Kenneth; Tassanakajon, Anchalee
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
EN
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A novel viral responsive protein, namely hemocyte homeostasis-associated protein (HHAP), was characterized for its role in the response of shrimp to white spot syndrome virus infection. The full-length cDNAs of HHAP from the black tiger shrimp (PmHHAP), Penaeus monodon, and the fresh water crayfish (PlHHAP), Pacifastacus leniusculus, were obtained and showed high sequence identity to a hypothetical protein from various organisms, with the highest identity to the hypothetical protein TcasGA2_TC006773 from the red flour beetle, Tribolium castaneum (54% amino acid sequence identity). Transcripts of PmHHAP were expressed in various shrimp tissues with the highest expression in hematopoietic tissue, whereas the transcripts of PlHHAP were found in the hematopoietic and nerve tissues. Upon white spot syndrome virus infection, a high up-regulation level of shrimp hemocytic HHAP mRNA and protein was observed by real-time reverse transcription-PCR and immunofluorescence microscopy, respectively. Gene silencing of PmHHAP by RNA interference resulted in a significant decrease in the number of circulating hemocytes and 100% shrimp mortality within 30 h of the double-stranded PmHHAP RNA injection (but not in control shrimp), indicating that HHAP is essential for shrimp survival. Interestingly...

High Hemocyte Load Is Associated with Increased Resistance against Parasitoids in Drosophila suzukii, a Relative of D. melanogaster

Kacsoh, Balint Z.; Schlenke, Todd A.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 17/04/2012 EN
Relevância na Pesquisa
27.62%
Among the most common parasites of Drosophila in nature are parasitoid wasps, which lay their eggs in fly larvae and pupae. D. melanogaster larvae can mount a cellular immune response against wasp eggs, but female wasps inject venom along with their eggs to block this immune response. Genetic variation in flies for immune resistance against wasps and genetic variation in wasps for virulence against flies largely determines the outcome of any fly-wasp interaction. Interestingly, up to 90% of the variation in fly resistance against wasp parasitism has been linked to a very simple mechanism: flies with increased constitutive blood cell (hemocyte) production are more resistant. However, this relationship has not been tested for Drosophila hosts outside of the melanogaster subgroup, nor has it been tested across a diversity of parasitoid wasp species and strains. We compared hemocyte levels in two fly species from different subgroups, D. melanogaster and D. suzukii, and found that D. suzukii constitutively produces up to five times more hemocytes than D. melanogaster. Using a panel of 24 parasitoid wasp strains representing fifteen species, four families, and multiple virulence strategies, we found that D. suzukii was significantly more resistant to wasp parasitism than D. melanogaster. Thus...

Tissue-enriched expression profiles in Aedes aegypti identify hemocyte-specific transcriptome responses to infection

Choi, Young-Jun; Fuchs, Jeremy F.; Mayhew, George F.; Yu, Helen E.; Christensen, Bruce M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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Hemocytes are integral components of mosquito immune mechanisms such as phagocytosis, melanization, and production of antimicrobial peptides. However, our understanding of hemocyte-specific molecular processes and their contribution to shaping the host immune response remains limited. To better understand the immunophysiological features distinctive of hemocytes, we conducted genome-wide analysis of hemocyte-enriched transcripts, and examined how tissue-enriched expression patterns change with the immune status of the host. Our microarray data indicate that the hemocyte-enriched trascriptome is dynamic and context-dependent. Analysis of transcripts enriched after bacterial challenge in circulating hemocytes with respect to carcass added a dimension to evaluating infection-responsive genes and immune-related gene families. We resolved patterns of transcriptional change unique to hemocytes from those that are likely shared by other immune responsive tissues, and identified clusters of genes preferentially induced in hemocytes, likely reflecting their involvement in cell type specific functions. In addition, the study revealed conserved hemocyte-enriched molecular repertoires which might be implicated in core hemocyte function by cross-species meta-analysis of microarray expression data from Anopheles gambiae and Drosophila melanogaster.

Circulating Biomphalaria glabrata hemocyte subpopulations possess shared schistosome glycans and receptors capable of binding larval glycoconjugates

Yoshino, Timothy P.; Wu, Xiao-Jun; Gonzalez, Laura A.; Hokke, Cornelis H.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.62%
Host lectin-like recognition molecules may play an important role in innate resistance in Biomphalaria glabrata snails to larval schistosome infection, thus implicating parasite-expressed glycans as putative ligands for these lectin receptors. While host lectins may utilize specific glycan structures for parasite recognition, it also has been hypothesized that the parasite may use this system to evade immune detection by mimicking naturally-expressed host glycans, resulting in reduced immunorecognition capacity. By employing immunocytochemical (ICC) and Western blot assays using schistosome glycan-specific monoclonal antibodies (mABs) we sought to identify specific glycan epitopes (glycotopes) shared in common between larval S. mansoni and B. glabrata hemocytes, the primary immune effector cells in snails. Results confirmed the presence of selected larval glycotopes on subpopulations of hemocytes by ICC and association with numerous hemocyte proteins by Western blot analyses, including a trimannosyl core N-glycan (TriMan), and two fucosylated lacdiNAc (LDN) variants, F-LDN and F-LDN-F. Snail strain differences were seen in the prevalence of constitutively expressed F-LDN on hemocytes, and in the patterns of protein immunoreactivity with these mABs. In contrast...

Hemocyte Density Increases with Developmental Stage in an Immune-Challenged Forest Caterpillar

Stoepler, Teresa M.; Castillo, Julio C.; Lill, John T.; Eleftherianos, Ioannis
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 06/08/2013 EN
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27.5%
The cellular arm of the insect immune response is mediated by the activity of hemocytes. While hemocytes have been well-characterized morphologically and functionally in model insects, few studies have characterized the hemocytes of non-model insects. Further, the role of ontogeny in mediating immune response is not well understood in non-model invertebrate systems. The goals of the current study were to (1) determine the effects of caterpillar size (and age) on hemocyte density in naïve caterpillars and caterpillars challenged with non-pathogenic bacteria, and (2) characterize the hemocyte activity and diversity of cell types present in two forest caterpillars: Euclea delphinii and Lithacodes fasciola (Limacodidae). We found that although early and late instar (small and large size, respectively) naïve caterpillars had similar constitutive hemocyte densities in both species, late instar Lithacodes caterpillars injected with non-pathogenic E. coli produced more than a twofold greater density of hemocytes than those in early instars. We also found that both caterpillar species contained plasmatocytes, granulocytes and oenocytoids, all of which are found in other lepidopteran species, but lacked spherulocytes. Granulocytes and plasmatocytes were found to be strongly phagocytic in both species...

Hemocyte–hemocyte adhesion and nodulation reactions of the greater wax moth, Galleria mellonella are influenced by cholera toxin and its B-subunit

Lapointe, Jason F.; Dunphy, Gary B.; Mandato, Craig A.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em 25/02/2012 EN
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28.02%
Nodulation, the lepidopteran insect immune response to large numbers of microbes in the blood (hemolymph) consists of the coordination of the blood cell (hemocyte) types the granular cells and plasmatocytes in terms of granular cell–bacteria adhesion and hemocyte–hemocyte adhesion (microaggregation). Hemocyte–microbe adhesion is influenced by the secondary messenger, cAMP, and cAMP-dependent protein kinase A. In the present study, cholera toxin, an AB5 protein known to indirectly stimulate adenylate cyclase, is used to examine the hemocyte responses to glass, bacteria and hemocyte–hemocyte microaggregates. In vitro, this toxin induces a bimodal hemocyte adhesion response that varies with the holotoxin concentration in terms of the individual and aggregated hemocyte adhesion responses: the lower CTX concentration (1.2 nM) increases microaggregate adhesion and decreases individual hemocyte binding to glass, as does higher concentrations (6–120 nM), however microaggregates induced by lower concentrations do not adhere to glass. Cholera toxin-induced microaggregation is inhibited by RGDS, suggestive of integrin involvement. In vivo, cholera toxin (1.2–120 nM) injected into larvae induces also a bimodal hemocytic response: low levels (1.2–6 nM) cause reduced hemocyte adhesion...

The Nimrod transmembrane receptor Eater is required for hemocyte attachment to the sessile compartment in Drosophila melanogaster

Bretscher, Andrew J.; Honti, Viktor; Binggeli, Olivier; Burri, Olivier; Poidevin, Mickael; Kurucz, Éva; Zsámboki, János; Andó, István; Lemaitre, Bruno
Fonte: The Company of Biologists Publicador: The Company of Biologists
Tipo: Artigo de Revista Científica
Publicado em 13/02/2015 EN
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27.5%
Eater is an EGF-like repeat transmembrane receptor of the Nimrod family and is expressed in Drosophila hemocytes. Eater was initially identified for its role in phagocytosis of both Gram-positive and Gram-negative bacteria. We have deleted eater and show that it appears to be required for efficient phagocytosis of Gram-positive but not Gram-negative bacteria. However, the most striking phenotype of eater deficient larvae is the near absence of sessile hemocytes, both plasmatocyte and crystal cell types. The eater deletion is the first loss of function mutation identified that causes absence of the sessile hemocyte state. Our study shows that Eater is required cell-autonomously in plasmatocytes for sessility. However, the presence of crystal cells in the sessile compartment requires Eater in plasmatocytes. We also show that eater deficient hemocytes exhibit a cell adhesion defect. Collectively, our data uncovers a new requirement of Eater in enabling hemocyte attachment at the sessile compartment and points to a possible role of Nimrod family members in hemocyte adhesion.

A calreticulin-like protein from endoparasitoid venom fluid is involved in host hemocyte inactivation

Zhang, G.; Schmidt, O.; Asgari, S.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
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37.5%
During oviposition, most endoparasitoid wasps inject maternal factors into their hosts to interfere with host immune reactions and ensure successful development of their progeny. Since encapsulation is a major cellular defensive response of insects against intruding parasites, parasitoids have developed numerous mechanisms to suppress the host encapsulation capability by interfering with every step in the process, including recognition, adherence and spreading. In previous studies, components of Cotesia rubecula venom were shown to inhibit melanization of host hemolymph by interfering with the prophenoloxidase activation cascade and facilitate expression of polydnavirus genes. Here we report the isolation and characterization of another venom protein with similarity to calreticulin. Results indicate that C. rubecula calreticulin (CrCRT) inhibits hemocyte spreading behavior, thus preventing encapsulation of the developing parasitoid. It is possible that the protein might function as an antagonist competing for binding sites with the host hemocyte calreticulin, which mediates early-encapsulation reactions.; http://www.elsevier.com/wps/find/journaldescription.cws_home/275/description#description; Guangmei Zhang, Otto Schmidt and Sassan Asgari

The Involvement of Hemocyte Prophenoloxidase in the Shell-Hardening Process of the Blue Crab, Callinectes sapidus

Alvarez, Javier V.; Chung, J. Sook
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 22/09/2015 EN
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27.62%
Cuticular structures of arthropods undergo dramatic molt-related changes from being soft to becoming hard. The shell-hardening process of decapod crustaceans includes sclerotization and mineralization. Hemocyte PPO plays a central role in melanization and sclerotization particularly in wound healing in crustaceans. However, little is known about its role in the crustacean initial shell-hardening process. The earlier findings of the aggregation of heavily granulated hemocytes beneath the hypodermis during ecdysis imply that the hemocytes may be involved in the shell-hardening process. In order to determine if hemocytes and hemocyte PPO have a role in the shell-hardening of crustaceans, a knockdown study using specific CasPPO-hemo-dsRNA was carried out with juvenile blue crabs, Callinectes sapidus. Multiple injections of CasPPO-hemo-dsRNA reduce specifically the levels of CasPPO-hemo expression by 57% and PO activity by 54% in hemocyte lysate at the postmolt, while they have no effect on the total hemocyte numbers. Immunocytochemistry and flow cytometry analysis using a specific antiserum generated against CasPPO show granulocytes, semigranulocytes and hyaline cells as the cellular sources for PPO at the postmolt. Interestingly, the type of hemocytes...

Activation of Drosophila hemocyte motility by the ecdysone hormone

Sampson, Christopher J.; Amin, Unum; Couso, Juan-Pablo
Fonte: The Company of Biologists Publicador: The Company of Biologists
Tipo: Artigo de Revista Científica
Publicado em 14/11/2013 EN
Relevância na Pesquisa
27.5%
Drosophila hemocytes compose the cellular arm of the fly's innate immune system. Plasmatocytes, putative homologues to mammalian macrophages, represent ∼95% of the migratory hemocyte population in circulation and are responsible for the phagocytosis of bacteria and apoptotic tissues that arise during metamorphosis. It is not known as to how hemocytes become activated from a sessile state in response to such infectious and developmental cues, although the hormone ecdysone has been suggested as the signal that shifts hemocyte behaviour from quiescent to migratory at metamorphosis. Here, we corroborate this hypothesis by showing the activation of hemocyte motility by ecdysone. We induce motile behaviour in larval hemocytes by culturing them with 20-hydroxyecdysone ex vivo. Moreover, we also determine that motile cell behaviour requires the ecdysone receptor complex and leads to asymmetrical redistribution of both actin and tubulin cytoskeleton.