Puparium

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Martin, Jon H. - One of the best experts on this subject based on the ideXlab platform.

Streito Jean-claude - One of the best experts on this subject based on the ideXlab platform.

Camus, Josephine M. - One of the best experts on this subject based on the ideXlab platform.

Gongyin Ye - One of the best experts on this subject based on the ideXlab platform.

  • characterization of a cell death inducing endonuclease like venom protein from the parasitoid wasp pteromalus puparum hymenoptera pteromalidae
    Pest Management Science, 2020
    Co-Authors: Jiale Wang, Shan Xiao, Beibei Wang, Qi Fang, Todd Schlenke, Gongyin Ye
    Abstract:

    BACKGROUND Parasitoid wasps are valuable natural enemies for controlling pests. To ensure successful parasitism, these wasps inject venoms along with their eggs that are deposited either into or on their hosts. Parasitoid venoms regulate host behaviors, development, metabolism, and immune responses. Pteromalus puparum is a pupal endoparasitoid that parasitizes a number of butterflies, including the worldwide pest cabbage butterfly, Pieris rapae. Venom from P. puparum has a variety of effects on host hemocytes, including alteration of absolute and relative hemocyte counts, and inhibition of hemocyte spreading and encapsulation. In particular, P. puparum venom causes hemocyte cell death in vivo and in vitro. RESULTS Using assay-guided chromatography, a cell death-inducing venom fraction was identified and defined as P. puparum endonuclease-like venom protein (PpENVP). It belongs to the DNA/RNA non-specific endonuclease family, which contains two conserved endonuclease activation sites. We analyzed its expression profiles and demonstrated that PpENVP inhibits gene expression in transfected cells relying on two activation sites. However, RNA interference of PpENVP did not significantly reduce P. puparum venom cytotoxicity, suggesting that PpENVP may not be the sole cytotoxic factor present. CONCLUSION Our results provide novel insight into the function of the P. puparum venom cocktail and identify a promising insecticide candidate endonuclease that targets insect hemocytes. This article is protected by copyright. All rights reserved.

  • parasitism of pieris rapae lepidoptera pieridae by a pupal endoparasitoid pteromalus puparum hymenoptera pteromalidae effects of parasitization and venom on host hemocytes
    Journal of Insect Physiology, 2004
    Co-Authors: Gongyin Ye, Cui Hu
    Abstract:

    In contrast to the situation with egg-larval and larval endoparasitic wasps, little is known about the effects of pupal endoparasitoids and their secretions on the hemocytes of their insect hosts. This study focuses on the pupal endoparasitoid, Pteromalus puparum, and its host, the small white butterfly, Pieris rapae. Parasitism by P. puparum, resulted in a significant increase in the total number of host hemocytes up to day five after parasitization. From day one to day four after parasitization, the percentage of plasmatocytes significantly decreased, and the proportion of granular cells increased. Moreover, from 12 h to day three after parasitization, hemocyte mortality in parasitized pupae was noticeably higher. When P. rapae pupae were parasitized by adult females of P. puparum irradiated by γ-ray (pseudoparasitization), it was clear that the treated wasps could induce similar hemocyte changes. However, such phenomena did not occur in punctured host pupae (mimic-parasitization). After treatment with P. puparum venom, both the percentages of spreading plasmatocytes and encapsulated Sephadex G-25 beads were lessened significantly in vitro. Electron microscopy analysis and visualization of hemocyte F-actin with phalloidin-FITC showed that hemocytes treated with venom had a rounded configuration and neither spread nor extended pseudopods, while there was no marked alteration of hemocyte cytoskeletons after venom treatment. The results suggested that venom of P. puparum could actively suppress the hemocyte immune response of its host, but not by destroying the host hemocyte cytoskeleton.

Luis A. Quesada-allué - One of the best experts on this subject based on the ideXlab platform.

  • Metamorphosis and gonad maturation in the horn fly Haematobia irritans.
    Journal of Insect Science, 2011
    Co-Authors: Alicia Basso, Natalia Soledad Forneris, Adrián Filiberti, Carlos E. Argaraña, Alejandro Rabossi, Luis A. Quesada-allué
    Abstract:

    The bloodsucking horn fly, Haematobia irritans (L.) (Diptera: Muscidae), is one of the most damaging pests of pasture cattle in many areas of the world. Both male and female imagoes spend their adult stage on the host, while immature stages develop in dung. Our goal was to determine if the progress of H. irritans gonad maturation can be correlated with eye and cuticle pigmentation events that occur during development of the imago within the Puparium. The progression of germline cell divisions in immature gonads was analyzed from the beginning of the third larval instar (48 hours after egg hatch) until imago ecdysis. In the developing male larval gonad, meiosis began 72 hours after egg hatch, whereas in females oogonia were premeiotic at 72 hours. Meiosis was not detected in females until the mid-pharate adult stage, 120 hours after Puparium formation. Therefore, gonad maturation in females appears to be delayed 144 hours with respect to that in males. In the stages within the Puparium, the timing of germline cell division events was correlated with the progress of pigmentation of the eyes and cuticle as external markers.

  • White pupa: a Ceratitis capitata mutant lacking catecholamines for tanning the Puparium
    Insect Biochemistry and Molecular Biology, 1995
    Co-Authors: Pablo Wappner, Karl J. Kramer, Theodore L. Hopkins, Matthew E. Merritt, Jacob Schaefer, Luis A. Quesada-allué
    Abstract:

    Abstract The white pupa mutant of the Mediterranean fruit fly, Ceratitis capitata , fails to tan the Puparium, but develops normal larval and adult cuticular structures. We found that the Puparium of this mutant underwent minor stiffening at the beginning of pupariation, but subsequently did not increase further in stiffness. By the end of poparium formation, it was fivefold less resistant to compression than the wild type strain, Scanning electron microscopy of cross-sections of puparial exuviae revealed a dense sclerotized cuticle in the wild type, whereas the white pupa cuticle was quite distinct, with the inner two-thirds consisting of unsclerotized lamellae and the outer third being a dense, nonlaminar, amorphous layer. Puparial catecholamine levels were also very low in the white pupa when compared with the wild type strain, in which N -β-alanyldopamine (NBAD) predominated. However, in mutant hemolymph, NBAD, N -acetyldopamine (NADA), and dopamine were about 10 times more concentrated than in the normal phenotype. By injecting 1- 14 C-β-alanine as a tracer, we confirmed that N -β-alanyldopamine incorporation into the Puparium was much lower in the white pupa than in the wild type strain. However, insoluble cuticle phenoloxidase activity was similar in the two strains. Tanning occurred in vitro when white pupa puparial cuticle, free of epidermis, was incubated with either NBAD or NADA, and melanization occurred when the cuticle was incubated with dopamine, demonstrating that tanning enzymes, but not substrates, were present in white pupa puparial cuticle. Solid state 3 C nuclear magnetic resonance spectroscopy revealed that more chitin as well as less protein, catechols and β-alanine were present in the white pupa cuticle relative to the wild type. We conclude that the white pupa mutant is defective in the mechanism that provides hemolymph catecholamines to the puparial cuticle; this defect prevents normal sclerotization and pigmentation.

  • Morphogenesis and cuticular markers during the larval-pupal transformation of the medfly Ceratitis capitata
    Entomologia Experimentalis et Applicata, 1991
    Co-Authors: A. Rabossi, Pablo Wappner, Graciela Lidia Boccaccio, Luis A. Quesada-allué
    Abstract:

    Changes in morphology during early metamorphosis of the medfly, Ceratitis capitata (Wied.) (Tephritidae) were correlated with biochemical differentiation events. Protein profiles were studied both in the 3rd instar larval cuticle further transformed into Puparium and the newly synthesized pupal cuticle. Beta-alanine incorporation into the Puparium (0–20 h) correlates with concomitant pigmentation (completed by 16 h) and sclerotization phenomena. This early ‘tannification program seems to be followed by deposition of a layer of substances, probably ecdysial fluid remnants, into the Puparium. Their deposition ends approximately at +46 h. Simultaneously, pupal cuticle material starts to be deposited. Synthesis and deposition of the main pupal cuticle protein was detected 48 h after pupariation. At that time, eversion of the pupal head occurs. The definitive profile of pupal cuticle proteins was attained at around +72 h together with the establishment of adult body proportions.

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