Lack of intraspecific biological variation between two geographical populations of Oomyzus sokolowskii (Hymenoptera: Eulophidae), a gregarious larval–pupal parasitioid of Plutella xylostella (Lepidoptera: Plutellidae)

The chalcid, Oomyzus sokolowskii Kurdjumov has been recorded in many parts of the world as a major larval-pupal, gregarious endoparasitoid of the diamondback moth, Plutella xylostella (Linnaeus), a serious pest of brassica vegetable crops worldwide. This study investigated intraspecific variation between two populations of O. sokiolowskii, one from Cape Verde Islands, West Africa and the other from Hangzhou, China. In all crosses and backcrosses between the two geographical populations, the numbers of progeny and sex ratio of progeny were similar to those obtained within each of the populations, demonstrating complete reproductive compatibility between the two populations. The two populations showed similar responses to temperature with respect to development time and survival of immature stages. Observations on the interactions between the two O. sokolowskii populations and Cotesia plutellae (Kurdjumov), another major parasitoid of P. xylostella, showed that neither population could achieve successful parasitism of P. xylostella larvae already parasitized by C. plutellac. However, both O. sokolowskii populations could achieve hyperparasitism by ovipositing into a mid-late stage larva of C. plutellae developing inside the primary host. Contrary to earlier reports, no evidence of intraspecific variations in ability to hyperparasitize between these two populations of O. sokolowskii was found.

Are insect immune suppressors driving cellular uptake reactions?

Many insect parasitoids that deposit their eggs inside immature stages of other insect species inactivate the cellular host defence to protect the growing embryo from encapsulation. Suppression of encapsulation by polydnavirus-encoded immune-suppressors correlates with specific alterations in hemocytes, mainly cytoskeletal rearrangements and actin-cytoskeleton breakdown. We have previously shown that the Cotesia rubecula polydnavirus gene product CrV1 causes immune suppression when injected into the host hemocoel. CrV1 is taken up by hemocytes although no receptors have been found to bind the protein. Instead CrV1 uptake depends on dimer formation, which is required for interacting with lipophorin, suggesting a CrV1-lipophorin complex internalisation by hemocytes. Since treatment of hemocytes with oligomeric lectins and cytochalasin D can mimic the effects of CrV1, we propose that some dimeric and oligomeric adhesion molecules are able to cross-link receptors on the cell surface and depolymerise actin by leverage-mediated clearance reactions in the hemolymph.

Toxicidade de extratos vegetais ao percevejo bronzeado do eucalipto Thaumastocoris peregrinus (hemiptera: heteroptera: thaumastocoridae) e organismos não-alvo

Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae ) is an insect from Australia which is causing severe damage to eucalyptus crops around the world. When feeding from the leaves sap, it causes bronzening, and in extreme cases, may lead to the tree death. Control methods have been studied and the most promising so far is the egg parasitoid Cleruchoides noackae (Hymenoptera: Mymaridae). Alternative products from plants with insecticidal properties could also be a viable option, and they might even be used concomitantly with C. noackae, aiming for a most effective control, but still safe for the environment. Thus, the objective of this work was to verify the action of 5% aqueous plant extracts of Matricaria chamomilla, Echinodorus grandiflorus, Punica granatum, Maytenus ilicifolia a n d Origanum majorana on T. peregrinus. In addition, we aimed to study the extracts potential toxicity to C. noackae and Gallus domesticus L., since the plant compounds might have negative effect upon the non-target organisms. At first, HPLC (High Performance Liquid Chromatography) was used to verify which phenolic compounds would be found in the plant extracts. These were tested on bronze bug adults, in confinement test (to verify the insecticidal action of the extracts) and free-choice test (to verify the repellency). The extracts that showed better results were selected for further tests with non-target organisms. Regarding C. noackae, pre-parasitism and post-parasitism, confinement and free-choice tests were performed to verify if the extracts would affect the host-choosing by the female or the development of the immature stages of the parasitoid. To verify if the extracts would be toxic to G. domesticus, the plant extracts were added to young birds feed for five days. Parameters such as weight gain, food intake, quantification of serum enzymes and histopathological analysis were carried out. HPLC analysis detected gallic, ferulic, vanillic, caffeic and cumaric acid in the extracts samples. All plant extracts tested reduced T. peregrinus survival, but E. grandiflorus, Matricaria chamomilla Maytenus ilicifolia had also a repellent effect, and were tested on the non-target organisms. None of these extracts affected neither the host choice by C. noackae nor adult emergency, when compared to the control group. In addition, the extracts did not cause alterations in any of the studied parameters. Thus, we verified that E. grandiflorus, Matricaria chamomilla and Maytenus ilicifolia have potential to be used to control T. peregrinus and are safe to C. noackae and G. domesticus.

Estrutura de populações de Rhodnius neglectus Lent e Psammolestes tertius Lent & Jurberg (Hemiptera, Reduviidae) em ninhos de pássaros (Furnariidae) presentes na palmeira Mauritia flexuosa no Distrito Federal, Brasil

Rhodnius neglectus Lent, 1954 {Rn}e Psammolestes tertius Lent & Jurberg, 1965 {Pt} são triatomíneos que ocorrem em ninhos de aves, principalmente da família Furnariidae. O ciclo biológico dessas espécies é conhecido em condições de laboratório, sendo poucos estudos em ecótopos silvestres. Para analisar a infestação e estrutura de populações de Rn e Pt em ninhos de aves presentes na palmeira Mauritia flexuosa Linnaeus, em duas estações climáticas do Brasil Central, foram amostradas 41 palmeiras com evidências de nidificação dePhacellodomus ruber Vieillot, 1817 (22 na estação chuvosa e 19 na estação seca) em quatro áreas do Distrito Federal. Os insetos foram capturados usando-se coleta manual na copa da palmeira, identificados morfologicamente, separados por sexo e estádio ninfal. Fezes e glândulas salivares de Rn foram examinadas para verificar infecção por Trypanosoma cruzi Chagas, 1909 e/ou T. rangeli Tejera, 1920. Trinta e cinco palmeiras com ninhos de P. ruber estavam infestadas por Rn (85%) e 22 por Pt (53%). 442 indivíduos foram coletados na estação seca (200 Rn e 242 Pt) e 267 na estação chuvosa (136 Rn e 131 Pt). O único fator relacionado significativamente com a densidade de triatomíneos nas palmeiras foi a área. A estrutura etária das populações mostrou: a) maior abundância de adultos nas populações de Pt, b) maior abundância de machos em ambas as espécies e c) presença de fêmeas ovipondo em ambas as estações. Nenhum dos 177 triatomíneos examinados estava infectado por T. cruzi ou T. rangeli. A estrutura etária das populações de Rn e Pt não diferiu significativamente entre as estações amostradas, indicando ausência de marcada sazonalidade para essas espécies. _______________________________________________________________________________________ ABSTRACT

Most lymphoid organ dendritic cell types are phenotypically and functionally immature

Dendritic cells (DCs) have been thought to follow a life history, typified by Langerhans cells (LCs), with 2 major developmental stages: an immature stage that captures antigens in the periphery and a mature stage that presents those antigens in the lymphoid organs. However, a systematic assessment of the maturity of lymphoid organ DCs has been lacking. We have analyzed the maturity of the DC types found in the steady state in the spleen, lymph nodes (LNs), and thymus. The DCs that migrate into the iliac, mesenteric, mediastinal, or subcutaneous LNs from peripheral tissues were mature and therefore could not process and present newly encountered antigens. However, all the other DC types were phenotypically and functionally immature: they expressed low levels of surface major histocompatibility complex class 11 (MHC 11) and CD86, accumulated MHC 11 in their endosomes, and could present newly encountered antigens. These immature DCs could 1346 induced to mature by culture in vitro or by Inoculation of inflammatory stimuli in vivo. Therefore, the lymphoid organs contain a large cohort of immature DCs, most likely for the maintenance of peripheral tolerance, which can respond to infections reaching those organs and mature in situ. (C) 2003 by The American Society of Hematology.

Bovine oocyte vitrification: Effect of ethylene glycol concentrations and meiotic stages

Success in oocyte cryopreservation is limited and several factors as cryoprotectant type or concentration and stage of oocyte meiotic maturation are involved. The aim of the present study was to evaluate the effect of maturation stage and ethylene glycol (EG) concentration on survival of bovine oocytes after vitrification. In experiment 1, kinetics of oocyte in vitro maturation (IVM) was evaluated. Germinal vesicle (GV), germinal vesicle breakdown (GVBD), metaphase I (MI), and metaphase II (MII) oocytes were found predominantly at 0, 0-10, 10-14, and 18-24 h of INK respectively. In experiment 2, in vitro embryo development after in vitro fertilization (IVF) of oocytes exposed to equilibrium (ES) and vitrification solution VS-1 (EG 30%), or VS-2 (EG 40%) at 0, 12 or 18 It of IVM was evaluated. Only blastocyst rate from oocytes vitrified in SV-2 after 18 h of IVM was different from control oocytes. Hatched blastocyst rates from oocytes vitrified in VS-1 after 12 and 18 h, and SV-2 after 18 h of IVM were different from unvitrified oocytes. In experiment 3, embryo development was examined after IVF of oocytes vitrified using VS-I or VS-2 at 0, 12 or 18 h of IVM. Rates of blastocyst development after vitrification of oocytes in VS-1 at each time interval were similar. However, after vitrification in VS-2, blastocyst rates were less at 18 h than 0 h. Both cleavage rates and blastocyst rates were significantly less in all vitrification groups when compared to control group and only control oocytes hatched. In conclusion, both EG concentration and stage of meiotic maturation affect the developmental potential of oocytes after vitrification. (C) 2007 Elsevier B.V. All rights reserved.

Chemotherapeutic effects on larval stages of Schistosoma mansoni during infection and re-infection of mice

The sensitivity of the larval stages of Schistosoma mansoni to chemotherapy with praziquantel and oxamniquine was tested in mice during primary and secondary infections and after different intervals from cercarial exposure. Worm recovery by perfusion of the porto-mesenteric system, followed by counting and a morphometric study of the parasite, allowed the conclusion that the relative resistance of the larval stages of S. mansoni to schistosomicide drugs, demonstrated in primary infections, also persists when the host is already infected. This indicates that a therapeutic failure may result when an infected host is treated some time after being re-infected, because of the presence of migrating, drug-resistant, immature forms of the parasite.

Immature mosquitoes (Diptera: Culicidae) in a eutrophic landfill tank from State of Rio de Janeiro, Brazil

Introduction To determine the faunal composition of immature culicids inhabiting a percolation tank in the landfill of Sapucaia, State of Rio de Janeiro, Brazil, immature mosquitoes were collected over a two-day period during the third weeks of April, August and October 2011. Results The species found were Culex usquatus, Lutzia bigoti, Anopheles argyritarsis and Limatus durhamii. This study is the first to report the colonization of eutrophic breeding sites by these species. Conclusions The oviposition behavior observed in this study suggests a secondary adaptation or change in habit to select eutrophic environments during the developmental stages of the observed species.

Development of a well-defined medium for the in vitro maturation of immature bovine cumulus-oocyte complexes.

PURPOSE: Our purpose was to develop a well-defined medium for the in vitro maturation (IVM) of immature bovine cumulus-oocyte complexes (COC). METHODS: The COC were cultured in the presence of three protein supplementations: fetal bovine serum (FBS), bovine serum albumin, and Synthetic Serum Substitute. The embryos obtained after in vitro fertilization of IVM oocytes were cocultured with Vero cells and their development to the morula and blastocyst stages was studied. RESULTS: When FBS was absent from the IVM medium, a significantly lower fertilization rate was observed, followed by a decrease in the percentage of embryos reaching the blastocyst stage. When FBS was replaced by a defined protein supplementation, the best results were obtained with Synthetic Serum Substitute. CONCLUSIONS: Adequate protein supplementation of the IVM medium optimizes the fertilization rate and the development of bovine IVM oocytes. The implication of these results in the human field is discussed.

Ly49D-mediated ITAM signaling in immature thymocytes impairs development by bypassing the pre-TCR checkpoint.

Activating and inhibitory NK receptors regulate the development and effector functions of NK cells via their ITAM and ITIM motifs, which recruit protein tyrosine kinases and phosphatases, respectively. In the T cell lineage, inhibitory Ly49 receptors are expressed by a subset of activated T cells and by CD1d-restricted NKT cells, but virtually no expression of activating Ly49 receptors is observed. Using mice transgenic for the activating receptor Ly49D and its associated ITAM signaling DAP12 chain, we show in this article that Ly49D-mediated ITAM signaling in immature thymocytes impairs development due to a block in maturation from the double negative (DN) to double positive (DP) stages. A large proportion of Ly49D/DAP12 transgenic thymocytes were able to bypass the pre-TCR checkpoint at the DN3 stage, leading to the appearance of unusual populations of DN4 and DP cells that lacked expression of intracellular (ic) TCRβ-chain. High levels of CD5 were expressed on ic TCRβ(-) DN and DP thymocytes from Ly49D/DAP12 transgenic mice, further suggesting that Ly49D-mediated ITAM signaling mimics physiological ITAM signaling via the pre-TCR. We also observed unusual ic TCRβ(-) single positive thymocytes with an immature CD24(high) phenotype that were not found in the periphery. Importantly, thymocyte development was completely rescued by expression of an Ly49A transgene in Ly49D/DAP12 transgenic mice, indicating that Ly49A-mediated ITIM signaling can fully counteract ITAM signaling via Ly49D/DAP12. Collectively, our data indicate that inappropriate ITAM signaling by activating NK receptors on immature thymocytes can subvert T cell development by bypassing the pre-TCR checkpoint.

Effects of Hormonal Supplementation on Nuclear Maturation and Cortical Granules Distribution of Canine Oocytes During Various Reproductive Stages

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Activity of pectinmethylesterase, pectin content and vitamin C in acerola fruit at various stages of fruit development

In order to know which stage of fruit development is better for acerola industrialization, we studied the PME specific activity, pectin content and vitamin C at various stages of development. The acerola fruits were classified according to colour and weight in five stages: immature green (2.62-3.21 g), green (4.04-4.83 g), mature green/yellow (5.03-5.88 g), pale-red (6.16-6.77 g) and ripe mature (6.92-8.37 g). The results showed that the highest content of pectin and vitamin C occurred at the immature green stage, 4.51 +/- 0.1% yield, 2424 mg/100 g of pulp and decreased as fruit ripened, 2.99 +/- 0.03% yield, 957 +/- 0.0 mg/100 g of pulp, respectively. However, at the same stages, the values of PME specific activity were lowest, 0.61 +/- 0.01 and 0.55 +/- 0.0 units g(-1)/g of pulp, respectively. The highest value of PME activity was 2.08 +/- 0.01 units g(-1)/g of pulp in the green stage. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Immature development in the tramp species ant Paratrechina longicornis (Hymenoptera, formicidae)

The genus Paratrechina (Motschulsky) is composed of about 147 cosmopolitan ant species and subspecies, of which some were accidentally spread by commerce around the world, infesting houses and hospitals. In Brazil, two species are of remarkable economic importance: Paratrechina fulva (Mayr) and Paratrechina longicornis (Latreille). The present paper aims to report the following aspects on the biology of P. longicornis: number of larval instars, growth rates, duration and viability of the developmental stages and some observations on brood-care behaviour. Artificial colonies were kept under controlled temperature (25±2°C) and relative humidity (60±10%) conditions. To access the number of larval instars, we analyzed 1531 larvae fixed in Dietrich by measuring their maximum head capsule widths. We analysed ten artificial colonies daily to measure the developmental time and viability of immatures. We found P. longicornis presented three larval instars and a mean growth ratio of 1.2988. Egg stage was found to last 16.1 ±0.1 days, with a viability of 24.6%; larval stages were found to last 18.3±0.1 days, with a viability of 33.3% and the pupal stage was found to last 12.3±0.1 days, with a viability of 65.3%.

Development stages of the reproductive tract of male of Panulirus echinatus Smith (Decapoda : Palinuridae)

This paper characterizes the developmental stages of the testes and vasa deferentia of the Panulirus echinatus Smith, 1869 through comparisons between microscopic findings, macroscopic aspects, and gonadosomatic index (GSR). The lobsters were sampled monthly (November 1999 to October 2000) using seine nets and a total of 1716 males were obtained at Tamandare Bay. Each carapace was cut to allow evaluation of the reproductive organs; the testes and vasa deferentia were dissected, weighed, fixed in Bouin`s solution up to 12 hours and submitted for histological analysis to determine the presence and/or absence of spermatozoa. These measures, along with change in color, size, diameter, development of the spermatophores and the GSR allowed the caracterization of three development stages: immature, intermediate and ripe. In conclusion, the maturity of the testes precedes the maturity of the vasa deferentia. To evaluate if gonadosomatic relation was a good quantitative indicator of the maturity stage, t tests (alpha = 0,05) were used and verified significant difference in the averages of GSR. The statistics corroborated that GSR can be used as indicative of the developmental stages for P. echinatus.

Observable stages and scheduling for alveolar remodeling following antemortem tooth loss

Zahnverlust zu Lebzeiten („antemortem tooth loss“, AMTL) kann als Folge von Zahnerkrankungen, Traumata, Zahnextraktionen oder extremer kontinuierlicher Eruption sowie als Begleiterscheinung fortgeschrittener Stadien von Skorbut oder Lepra auftreten. Nach dem Zahnverlust setzt die Wundheilung als Sekundärheilung ein, während der sich die Alveole mit Blut füllt und sich ein Koagulum bildet. Anschließend erfolgt dessen Umwandlung in Knochengewebe und schließlich verstreicht die Alveole derart, dass sie makroskopisch nicht mehr erkannt werden kann. Der Zeitrahmen der knöchernen Konsolidierung des Kieferkammes ist im Detail wenig erforscht. Aufgrund des gehäuften Auftretens von AMTL in menschlichen Populationen, ist die Erarbeitung eines Zeitfensters, mit dessen Hilfe durch makroskopische Beobachtung des Knochens die Zeitspanne seit dem Zahnverlust („time since tooth loss“, TSL) ermittelt werden kann, insbesondere im archäologischen Kontext äußerst wertvoll. Solch ein Zeitschema mit Angaben über die Variabilität der zeitlichen Abläufe bei den Heilungsvorgängen kann nicht nur in der Osteologie, sondern auch in der Forensik, der allgemeinen Zahnheilkunde und der Implantologie nutzbringend angewandt werden. rnrnNach dem Verlust eines Zahnes wird das Zahnfach in der Regel durch ein Koagulum aufgefüllt. Das sich bildende Gewebe wird rasch in noch unreifen Knochen umgewandelt, welcher den Kieferknochen und auch die angrenzenden Zähne stabilisiert. Nach seiner Ausreifung passt sich das Gewebe schließlich dem umgebenden Knochen an. Das Erscheinungsbild des Zahnfaches während dieses Vorgangs durchläuft verschiedene Stadien, welche in der vorliegenden Studie anhand von klinischen Röntgenaufnahmen rezenter Patienten sowie durch Untersuchungen an archäologischen Skelettserien identifiziert wurden. Die Heilungsvorgänge im Zahnfach können in eine prä-ossale Phase (innerhalb einer Woche nach Zahnverlust), eine Verknöcherungsphase (etwa 14 Wochen nach Zahnverlust) und eine ossifizierte bzw. komplett verheilte Phase (mindestens 29 Wochen nach Zahnverlust) eingeteilt werden. Etliche Faktoren – wie etwa die Resorption des Interdentalseptums, der Zustand des Alveolarknochens oder das Individualgeschlecht – können den normalen Heilungsprozess signifikant beschleunigen oder hemmen und so Unterschiede von bis zu 19 Wochen verursachen. Weitere Variablen wirkten sich nicht signifikant auf den zeitlichen Rahmen des Heilungsprozesse aus. Relevante Abhängigkeiten zwischen verschiedenen Variabeln wurden ungeachtet der Alveolenauffüllung ebenfalls getestet. Gruppen von unabhängigen Variabeln wurden im Hinblick auf Auffüllungsgrad und TSL in multivariablen Modellen untersucht. Mit Hilfe dieser Ergebnisse ist eine grobe Einschätzung der Zeitspanne nach einem Zahnverlust in Wochen möglich, wobei die Einbeziehung weiterer Parameter eine höhere Präzision ermöglicht. rnrnObwohl verschiedene dentale Pathologien in dieser Studie berücksichtigt wurden, sollten zukünftige Untersuchungen genauer auf deren potenzielle Einflussnahme auf den alveolaren Heilungsprozess eingehen. Der kausale Zusammenhang einiger Variablen (wie z. B. Anwesenheit von Nachbarzähnen oder zahnmedizinische Behandlungen), welche die Geschwindigkeit der Heilungsrate beeinflussen, wäre von Bedeutung für zukünftige Untersuchungen des oralen Knochengewebes. Klinische Vergleichsstudien an forensischen Serien mit bekannter TSL oder an einer sich am Anfang des Heilungsprozesses befindlichen klinischen Serie könnten eine Bekräftigung dieser Ergebnisse liefern.