Defence strategies against a parasitoid wasp in
            Drosophila
            : fight or flight?

Hosts may defend themselves against parasitism through a wide variety of defence mechanisms, but due to finite resources, investment in one defence mechanism may trade-off with investment in another mechanism. We studied resistance strategies against the parasitoid wasp Leptopilina boulardi in two Drosophila species. We found that D. melanogaster had significantly lower physiological resistance against L. boulardi than D. simulans , and hypothesized that D. melanogaster might instead invest more heavily in other forms of defence, such as behavioural defence. We found that when given a choice between clean oviposition sites and sites infested with wasps, both D. melanogaster and D. simulans detected and avoided infested sites, which presumably limits later exposure of their offspring to infection. Unlike D. simulans , however, D. melanogaster laid significantly fewer eggs than controls in the forced presence of wasps. Our findings suggest that D. melanogaster relies more heavily on behavioural avoidance as defence against wasp parasitism than D. simulans , and that this may compensate for a lack of physiological defence.

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Growing and Flowering in a Changing Climate: Effects of Higher Temperatures and Drought Stress on the Bee-Pollinated Species Impatiens glandulifera Royle

Plants ◽

10.3390/plants10050988 ◽

2021 ◽

Vol 10 (5) ◽

pp. 988

Author(s):

Charlotte Descamps ◽

Najet Boubnan ◽

Anne-Laure Jacquemart ◽

Muriel Quinet

Keyword(s):

Climate Change ◽

Drought Stress ◽

Floral Traits ◽

Limited Resources ◽

Plant Growth And Development ◽

Impatiens Glandulifera ◽

Nectar Volume ◽

Resistance Strategies ◽

Physiological Resistance ◽

Impatiens Glandulifera Royle

Drought and higher temperatures caused by climate change are common stress conditions affecting plant growth and development. The reproductive phase is particularly sensitive to stress, but plants also need to allocate their limited resources to produce floral traits and resources to attract pollinators. We investigated the physiological and floral consequences of abiotic stress during the flowering period of Impatiens glandulifera, a bee-pollinated species. Plants were exposed to three temperatures (21, 24, 27 °C) and two watering regimes (well-watered, water stress) for 3 weeks. Not all parameters measured responded in the same manner to drought and/or heat stress. Drought stress induced leaf senescence, decreasing leaf number by 15–30% depending on growth temperature. Drought also reduced photosynthetic output, while temperature rise affected stomatal conductance. The number of flowers produced dropped 40–90% in response to drought stress, while higher temperatures shortened flower life span. Both stresses affected floral traits, but flower resources diminished in response to higher temperatures, with lower nectar volume and pollen protein content. We conclude that increased temperatures and drought stress, which are becoming more frequent with climate change, can negatively affect flowering, even if plants deploy physiological resistance strategies.

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What is the Evolutionary Advantage of Migraine?

Cephalalgia ◽

10.1046/j.1468-2982.2002.00437.x ◽

2002 ◽

Vol 22 (8) ◽

pp. 624-632 ◽

Cited By ~ 37

Author(s):

E Loder

Keyword(s):

Nervous System ◽

Natural Selection ◽

Environmental Factors ◽

Genetic Factors ◽

Evolutionary Perspective ◽

Defence Mechanism ◽

Design Constraint ◽

Trade Off ◽

Evolutionary Advantage ◽

Evolutionary Explanations

Susceptibility to migraine is determined by genetic factors and is therefore subject to the forces of natural selection. Migraine is a common and ancient disorder whose prevalence may be increasing, suggesting that a migraine-prone nervous system may be associated with reproductive or survival advantages. Five evolutionary explanations are reviewed that might account for the persistence of migraine: (i) migraine as a defence mechanism; (ii) migraine as a result of conflict with other organisms; (iii) migraine as result of novel environmental factors; (iv) migraine as a trade-off between genetic harms and benefits; and (v) migraine as a design constraint. An evolutionary perspective on migraine allows the generation of important hypotheses about the disorder and suggests rewarding possibilities for further research.

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A serpin from the parasitoid wasp Leptopilina boulardi targets the Drosophila phenoloxidase cascade

Developmental & Comparative Immunology ◽

10.1016/j.dci.2008.11.013 ◽

2009 ◽

Vol 33 (5) ◽

pp. 681-689 ◽

Cited By ~ 93

Author(s):

Dominique Colinet ◽

Aurore Dubuffet ◽

Dominique Cazes ◽

Sébastien Moreau ◽

Jean-Michel Drezen ◽

...

Keyword(s):

Parasitoid Wasp ◽

Leptopilina Boulardi

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Mapping candidate genes for Drosophila melanogaster resistance to the parasitoid wasp Leptopilina boulardi

Genetics Research ◽

10.1017/s001667230600841x ◽

2006 ◽

Vol 88 (2) ◽

pp. 81-91 ◽

Cited By ~ 15

Author(s):

M. HITA ◽

E. ESPAGNE ◽

F. LEMEUNIER ◽

L. PASCUAL ◽

Y. CARTON ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Candidate Genes ◽

Resistance Gene ◽

Molecular Level ◽

Single Gene ◽

Parasitoid Wasp ◽

Male Recombination ◽

Leptopilina Boulardi

Drosophila melanogaster resistance against the parasitoid wasp Leptopilina boulardi is under the control of a single gene (Rlb), with two alleles, the resistant one being dominant. Using strains bearing deletions, we previously demonstrated that the 55E2–E6; 55F3 region on chromosome 2R is involved in the resistance phenomenon. In this paper, we first restricted the Rlb containing region by mapping at the molecular level the breakpoints of the Df(2R)Pc66, Df(2R)P34 and Df(2R)Pc4 deficiencies, using both chromosomal in situ hybridization and Southern analyses. The resistance gene was localized in a 100 kb fragment, predicted to contain about 10 different genes. Male recombination genetic experiments were then performed, leading to identification of two possible candidates for the Rlb gene. Potential involvement of one of this genes, edl/mae, is discussed.

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Genetic interactions between the parasitoid wasp Leptopilina boulardi and its Drosophila hosts

Heredity ◽

10.1038/sj.hdy.6800893 ◽

2006 ◽

Vol 98 (1) ◽

pp. 21-27 ◽

Cited By ~ 46

Author(s):

A Dubuffet ◽

S Dupas ◽

F Frey ◽

J-M Drezen ◽

M Poirié ◽

...

Keyword(s):

Parasitoid Wasp ◽

Genetic Interactions ◽

Leptopilina Boulardi

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Genetic Localization of a Drosophila melanogaster Resistance Gene to a Parasitoid Wasp and Physical Mapping of the Region

Genome Research ◽

10.1101/gr.9.5.471 ◽

1999 ◽

Vol 9 (5) ◽

pp. 471-481

Author(s):

Maria Teresa Hita ◽

Maryléne Poirié ◽

Nathalie Leblanc ◽

Francoise Lemeunier ◽

Francoise Lutcher ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Physical Mapping ◽

Physical Map ◽

Single Gene ◽

Parasitoid Wasp ◽

Restriction Map ◽

Cross Hybridization ◽

Restriction Fragments ◽

Leptopilina Boulardi ◽

The Right

Drosophila melanogaster larvae usually react against eggs of the parasitoid wasp Leptopilina boulardi by surrounding them with a multicellular melanotic capsule. The genetic determinism of this response has been studied previously using susceptible (non-capsule-forming) and resistant (capsule-forming) strains. The results suggest that differences in their encapsulation response involve a single gene, resistance to Leptopilina boulardi(Rlb), with two alleles, the resistant one being dominant.Rlb confers specific protection against Leptopilina boulardi and is thus probably involved in parasitoid recognition. Recent studies have localized this gene on the right arm of the second chromosome and our aim was to precisely determine its genetic and molecular location. Using strains bearing deletions, we demonstrated that resistance to Leptopilina boulardi is conferred by the55C; 55F3 region and that the 55E2–E6; F3 region is particularly involved. A physical map of the 55C;56A region was then constructed, based on a set of overlapping cosmid and P1 phage clones. Using single and double digests, cross hybridization of restriction fragments, and location of genetically mapped genes and STSs, a complete, five-enzyme restriction map of this 830-kb region was obtained.

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The Defence Mechanism Test (DMT) revisited: experimental validation using threatening and non‐threatening pictures

European Journal of Personality ◽

10.1002/per.457 ◽

2002 ◽

Vol 16 (4) ◽

pp. 283-294 ◽

Cited By ~ 4

Author(s):

Bo Ekehammar ◽

Irena Zuber ◽

Margareta Simonsson‐Sarnecki

Keyword(s):

Information Processing ◽

Structural Properties ◽

Experimental Validation ◽

Emotional Content ◽

Correct Identification ◽

Defence Mechanism ◽

Defence Mechanisms ◽

Psychodynamic Theory ◽

Professional Artist

Although the Defence Mechanism Test (DMT) has been in use for almost half a century, it is still unclear what it actually measures. The psychodynamic theory on which the test is based states that the threatful DMT pictures activate various defence mechanisms. To test this proposition, the original DMT pictures were redrawn by a professional artist, changing the emotional content without altering the structural properties. In this way, a neutral and a friendly variant were shaped. Sixty participants were randomly assigned to the threatful, neutral, and friendly stimulus conditions. In contrast to predictions made from psychodynamic theory, that the threatful picture would activate more ‘signs of defence’ than the others, the results disclosed that the three conditions activated the same amounts of ‘signs of defence’ and the same levels of various perceptual thresholds. Thus, rather than capturing psychodynamic defence mechanisms, our results suggest that the DMT taps perceptual or information‐processing difficulties in correct identification of brief stimulus exposures regardless of their emotional contents. Copyright © 2002 John Wiley & Sons, Ltd.

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PIXE ANALYSIS OF THE SERUM OF MICE ACQUIRED RADIO-RESISTIBILITY BY LOW DOSE X-RAYS

International Journal of PIXE ◽

10.1142/s0129083596000302 ◽

1996 ◽

Vol 06 (01n02) ◽

pp. 291-298 ◽

Cited By ~ 1

Author(s):

Y. MATSUDA ◽

M. YONEZAWA ◽

F. NISHIYAMA

Keyword(s):

Low Dose ◽

Common Knowledge ◽

X Rays ◽

Defence Mechanism ◽

Defence Mechanisms ◽

Pixe Analysis ◽

Cell Counts ◽

Blood Cell Counts ◽

X Irradiation ◽

The Common

It is not only important for maintenance and improvement of health, but also indispensable for diagnosis and remedy of diseases to make inquiries into the biological defence mechanisms. Yonezawa et al. came across an induction of yet unknown defence mechanism(s) in mice which acquired radioresistance two weeks after low dose X-irradiation with 0.5 Gy. The 30-day survival rate after midlethal X-irradiation of the mice significantly increased by the pre-irradiation, but contrary to the common knowledge on radiation protection, recovery of the blood cell counts of thrombocytes, leukocytes and erythrocytes were not stimulated by the pre-irradiation. This study was planned to find some keys to elucidate the mechanism for the acquired radioresistance. Metal ions are well known to be important for enzyme activities as well as for metabolisms. Eleven elements, Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Se and Br were analysed in mice sera by PIXE.

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