jean luc gatti | Institut National de la Recherche Agronomique (original) (raw)

Papers by jean luc gatti

Additional file 11. Expression of Osiris genes. Expression details of Osiris genes in L. fabarum ... more Additional file 11. Expression of Osiris genes. Expression details of Osiris genes in L. fabarum and A. ervi, including comparison of expression between larval and adult L. fabarum.

data supporting results <br>

Data and scripts for the paper entitled "Parasitic success and venom composition evolve upon... more Data and scripts for the paper entitled "Parasitic success and venom composition evolve upon specialization of parasitoid wasps to different host species"<br>

Additional file 9. Venom gene annotations. Annotation details of venom genes in L. fabarum and A.... more Additional file 9. Venom gene annotations. Annotation details of venom genes in L. fabarum and A. ervi.

Journal of Insect Physiology, 2021

The Drosophila endoparasitoid wasps Leptopilina boulardi and L. heterotoma (Hymenoptera: Cynipida... more The Drosophila endoparasitoid wasps Leptopilina boulardi and L. heterotoma (Hymenoptera: Cynipidae) are pro-ovigenic species, i.e., females contain their lifetime number of mature eggs at emergence. They are therefore able to immediately parasitize many hosts when present. In response to parasitoid oviposition, the larval host D. melanogaster can mount an immune response, encapsulation, that can destroy the parasitoid eggs. This response is counteracted by the venom the wasp injects during oviposition. Here, we estimated the amount of venom injected into a D. melanogaster host larva using immunodetection of venom proteins and we attempted to correlate this amount with the number of eggs a female can lay on successive days. The venom reservoir of L. boulardi contains enough venom for at least 100 ovipositions while that of L. heterotoma contains venom for about 16 ovipositions. While a female L. boulardi may have enough venom for three days of parasitism when 20 or 40 larval hosts were presented each day, L. heterotoma certainly needs to synthesize new venom to parasitize the number of hosts offered. Interestingly, parasitism stopped (L. boulardi), egg protection (L. heterotoma) and egg hatching decreased (both species) after three days of parasitism. Thus, although venom does not appear to be a limiting factor for parasitism, our data suggest that it may have less effectiveness on the egg protection and on egg/host development after high repetitive egg laying.

Journal of Biological Chemistry, 1989

International audienc

Journal of Pest Science, 2020

Previous data showed that the parasitoid wasp Aphelinus asychis was more successful on Sitobion a... more Previous data showed that the parasitoid wasp Aphelinus asychis was more successful on Sitobion avenae clones artificially infected with different strains of Regiella insecticola compared to the same clones lacking facultative symbionts. To test whether this resulted from a specific interaction between the aphid and symbiont genotype, we used new clonal lines from a different genotype of S. avenae (Linyi) infected with the same R. insecticola strains. The parasitism rate of A. asychis was higher on the two Linyi lines infected with R. insecticola than on the uninfected control line, while the emergence rate was lower due to higher mortality during development. However, a different wasp species, Aphidius gifuensis, showed no difference in the parasitism rate and emergence rate between the three Linyi lines, suggesting that the increase in parasitism rate could be wasp species-dependent. The mortality of A. asychis during development in the presence of R. insecticola may be linked to (i) a direct toxic or metabolic effect since the weight of the emerged wasps was also reduced and (ii) a general effect on the aphid fitness since the survival and fecundity of infected aphids having survived A. asychis attack were clearly reduced compared to the control, while those surviving A. gifuensis attack had only a slight increase in their survival rate. Our data therefore enriched the panel of phenotypic effects that R. insecticola could contribute to the aphid and emphasized the potential implications of symbionts on biological pest control. Keywords Sitobion avenae • Parasitoid wasp • Regiella insecticola • Aphid genotype • Symbiont strains Key messages • A growing body of evidence suggests endosymbionts infecting insects may disrupt biological control of pests. • The grain aphid, Sitobion avenae, is a globally important pest, but knowledge of its symbionts, which may affect pest control, is limited. • Here, we show that Aphelinus asychis was more successful in parasitizing Sitobion avenae infected with the symbiont Regiella insecticola.

Reproductive Biology and Endocrinology, 2011

Fertilin alpha (ADAM-1) and beta (ADAM-2) are integral membrane proteins of the ADAM family that ... more Fertilin alpha (ADAM-1) and beta (ADAM-2) are integral membrane proteins of the ADAM family that form a fertilin complex involved in key steps of the sperm-oocyte membrane interaction. In the present work, we analyzed the presence of ADAM-1 and ADAM-2 mRNAs, the spermatozoa proteins' processing and their sub-cellular localization in epididymal samples from adult boars. ADAM-1 and ADAM-2 mRNAs were highly produced in the testis, but also in the vas efferens and the epididymis. On immunoblots of sperm extracts, ADAM-1 subunit appeared as a main reactive band of ~50-55 kDa corresponding to occurrence of different isoforms throughout the epididymal duct, especially in the corpus region where isoforms ranged from acidic to basic pI. In contrast, ADAM-2 was detected as several bands of ~90 kDa, ~75 kDa, ~50-55 kDa and ~40 kDa. The intensity of high molecular mass bands decreased progressively in the distal corpus where lower bands were also transiently observed, and only the ~40 kDa w...

BMC Genomics, 2009

Background Mammalians gamete production takes place in the testis but when they exit this organ, ... more Background Mammalians gamete production takes place in the testis but when they exit this organ, although spermatozoa have acquired a specialized and distinct morphology, they are immotile and infertile. It is only after their travel in the epididymis that sperm gain their motility and fertility. Epididymis is a crescent shaped organ adjacent to the testis that can be divided in three gross morphological regions, head (caput), body (corpus) and tail (cauda). It contains a long and unique convoluted tubule connected to the testis via the efferent ducts and finished by joining the vas deferens in its caudal part. Results In this study, the testis, the efferent ducts (vas efferens, VE), nine distinct successive epididymal segments and the deferent duct (vas deferens, VD) of four adult boars of known fertility were isolated and their mRNA extracted. The gene expression of each of these samples was analyzed using a pig generic 9 K nylon microarray (AGENAE program; GEO accession number: G...

Biology of Reproduction, 2002

Acquisition of sperm fertilizing ability is due, in part, to the reorganization of plasma membran... more Acquisition of sperm fertilizing ability is due, in part, to the reorganization of plasma membrane proteins that occurs during epididymal sperm transit. Using polyclonal antibodies against angiotensin I-converting enzyme (ACE), we showed that this enzyme is immunolocalized mainly on the middle piece of rat and mouse testicular sperm and with less intensity along the initial part of the principal piece of the flagellum. In both species, only some sperm from the caput epididymis were still reactive, whereas no labeling was observed on cauda epididymal sperm. The 105-to 110-kDa germinal ACE was absent from the rat testicular fluid but appeared in the fluid of the anterior epididymis. Thereafter, its molecular weight shifted to 94 kDa in the corpus epididymal fluid and remained at this weight in the caudal region. The 105-to 110-kDa immunoreactive protein was present in testicular rat sperm extract but was completely absent from epididymal sperm extracts. Western blot analysis of testicular and epididymal tissue extracts from the rat and mouse also confirmed that the germinal enzyme was absent from the epididymal sperm cell. Our results demonstrated that the rodent germinal ACE is released from the testicular sperm membrane when sperm enter the epididymis, a process similar to that observed in domestic mammals. This result is discussed in view of the suggested role for this enzyme in sperm fertility.

Biology of Reproduction, 2004

Cellular prion protein (Prp C) is a glycoprotein usually associated with membranes via its glycos... more Cellular prion protein (Prp C) is a glycoprotein usually associated with membranes via its glycosylphosphatidylinositol (GPI) anchor. The trans-conformational form of this protein (Prp SC) is the suggested agent responsible for transmissible neurodegenerative spongiform encephalopathies. This protein has been shown on sperm and in the reproductive fluids of males. Antibodies directed against the C-terminal sequence near the GPIanchor site, an N-terminal sequence, and against the whole protein showed that the Prp isoforms were compartmentalized within the reproductive tract of the ram. Immunoblotting with the three antibodies showed that the complete protein and both N-and C-terminally truncated and glycosylated isoforms are present within cauda epididymal fluid and seminal plasma. Moreover, we demonstrate that in these fluids, the Prp C isoforms are both in a soluble state as well as associated with small membranous vesicles (epididymosomes). We also report that only one major glycosylated 25 kDa C-terminally truncated Prp C isoform is associated with sperm from the testis, cauda epididymis, and semen, and this form is also present in the sperm cytoplasmic droplets that are released during maturation. In sperm, this Cterminal truncated form was found to be associated with membrane lipid rafts present in the mature sperm, suggesting a role for it in the terminal stages of sperm maturation.

Bioinsecticides made from the bacterium Bacillus thuringiensis (Bt) are the best-selling bioinsec... more Bioinsecticides made from the bacterium Bacillus thuringiensis (Bt) are the best-selling bioinsecticide worldwide. Among Bt bioinsecticides, those based on the strain Bt var. kurstaki (Btk) are widely used in farming to specifically control pest lepidopteran larvae. Although there is much evidence of the lack of acute lethality of Btk products for non-target animals, only scarce data are available on their potential non-lethal developmental adverse effects. Using doses that could be reached in the field upon sprayings, we have shown that Btk products impair growth and developmental time of the non-target dipteran Drosophila melanogaster. These effects are mediated by the synergy between Btk bacteria and Btk insecticidal toxins, which induces a significant apoptosis of larval enterocytes, resulting in a decreased intestinal capacity to digest proteins. The harmful effects can be mitigated by a protein-rich diet or by adding the probiotic bacterium Lactobacillus plantarum into the foo...

Most species in the order Hymenoptera are parasitoids that lay eggs and develop in or on the body... more Most species in the order Hymenoptera are parasitoids that lay
eggs and develop in or on the body of arthropod hosts. Several
factors contribute to successful parasitism including venoms
that wasps inject into hosts when ovipositing. Here, we review
the composition, function and diversity of parasitoid venoms
with emphasis on studies of wasps that parasitize hosts in the
genus Drosophila. The comparative literature indicates that
some closely related species parasitizing the same host do not
share any abundant venom protein while unrelated species
sometimes have the same major venom component. Within
species, studies also identify intraspecific variation that
suggests parasitoid venoms may rapidly evolve. Overall,
however, our picture of venom function remains largely unclear
and will require additional comparative data on the composition
of venoms from a greater diversity of species than exists
currently. Further advances will come mainly from experimental
data using functional tools, such as RNA interference.

Reproduction, 2006

Sperm cell surface proteins and proteins of their surrounding fluids are reported to be proteolyt... more Sperm cell surface proteins and proteins of their surrounding fluids are reported to be proteolytically processed in relation to acquisition of sperm fertility during epididymal transit. Several of these proteins might be potential targets for subtilisin-like pro-protein convertase. Using immunochemistry and mass spectrometry analysis, we found that an 80 kDa form of furin (EC 3.4.21.75) is present in the fluid from the mid-caput to the distal corpus regions of the epididymis of various domestic mammals. This protein is absent from the fluid of the caudal region, suggesting that it is reabsorbed or degraded. The cDNA sequence of ovine furin was obtained and the mRNA was found throughout this organ, although in greater amounts in the mid and distal caput regions. Metabolic labeling with (35)S-amino acids indicated that the protein was synthesized and released from the epithelium only in a restricted area of the mid-caput, suggesting a specific regionalized mechanism of secretion. The fluid protein is not pelleted at 100 000 g and did not react with a C-terminal antibody indicating that it is not bound to membranous materials. These findings demonstrate that a furin ectodomain shedding occurs naturally in vivo in the epididymis where this enzyme could be involved in fluid and/or sperm membrane protein processing.

We used in vitro translocation and cosedimentation assays to study the microtubule binding proper... more We used in vitro translocation and cosedimentation assays to study the microtubule binding properties of sea urchin sperm outer arm dynein and its/3/IC1 subunit. Microtubules glided on glassabsorbed sea urchin dynein for a period of time directly proportional to the initial MgATt n-concentration and then detached when 70-95 % of the MgATP 2was hydrolyzed. Detachment resulted from MgATP 2depletion, because (a) perfusion with fresh buffer containing MgATP 2-reconstituted binding and gliding, (b) microtubules glided many minutes with an ATPregenerating system at ATP concentrations which alone supported gliding for only 1-2 min, and (c) microtubules detached upon total hydrolysis of ATP by an ATP-removal system. The products of ATP hydrolysis antagonized binding and gliding; as little as a threefold excess of ADP/Pi over ATP resulted in complete loss of microtubule binding and translocation by the/~/IC1 subunit. In contrast to the situation with sea urchin dynein, microtubules ceased gliding but remained bound to glass-absorbed Tetrahymena outer arm dynein when MgATP 2-was exhausted. Cosedimentation assays showed that/ktrahymena outer arm dynein sedimented with microtubules in an ATPsensitive manner, as previously reported (Porter, M.E.,. However, the/3/IC1 subunit of sea urchin dynein did not cosediment with microtubules in the absence of ATE Thus, this subunit, while capable of generating motility, lacks both structural and rigortype microtubule binding.

Biochemical Journal, 2005

We have shown previously that a &amp;amp;amp;amp;amp;#39;soluble&amp;amp;amp;amp;... more We have shown previously that a &amp;amp;amp;amp;amp;#39;soluble&amp;amp;amp;amp;amp;#39; form of PrP (prion protein), not associated with membranous vesicles, exists in the male reproductive fluid [Ecroyd, Sarradin, Dacheux and Gatti (2004) Biol. Reprod. 71, 993-1001]. Attempts to purify this &amp;amp;amp;amp;amp;#39;soluble&amp;amp;amp;amp;amp;#39; PrP indicated that it behaves like a high-molecular-mass complex of more than 350 kDa and always co-purified with the same set of proteins. The main associated proteins were sequenced by MS and were found to match to clusterin (apolipoprotein J), BPI (bacterial permeability-increasing protein), carboxylesterase-like urinary excreted protein (cauxin), beta-mannosidase and beta-galactosidase. Immunoblotting and enzymatic assay confirmed the presence of clusterin and a cauxin-like protein and showed that a 17 kDa hydrophobic epididymal protein was also associated with this complex. These associated proteins were not separated by a high ionic strength treatment but were by 2-mercaptoethanol, probably due to its action on reducing disulphide bonds that maintain the interaction of components of the complex. Our results suggest that the associated PrP retains its GPI (glycosylphosphatidylinositol) anchor, in contrast with brain-derived PrP, and that it is resistant to cleavage by phosphatidylinositol-specific phospholipase C. Based on these results, the identity of the associated proteins and the overall biochemical properties of this protein ensemble, we suggest that &amp;amp;amp;amp;amp;#39;soluble&amp;amp;amp;amp;amp;#39; PrP can form protein complexes that are maintained by hydrophobic interactions, in a similar manner to lipoprotein vesicles or micellar complexes.

Reproduction, 2008

Scrapie is the most common transmissible spongiform encephalopathy (TSE) in livestock. Natural co... more Scrapie is the most common transmissible spongiform encephalopathy (TSE) in livestock. Natural contamination in sheep flocks is presumed to occur by maternal transmission to offspring. However, horizontal prion transmission from animal to animal exists and may be significant in sustaining and spreading contagion in the field. Artificial insemination is widely used in modern farming, and as large amounts of prion protein have been found in sheep sperm membrane, epididymal fluid and seminal plasma, horizontal transmission by this route was hypothesized since no clear information has been obtained on possible sexual transmission of TSE. We therefore tested the contamination levels of semen from scrapie-infected rams at different stages of incubation, including the clinical phase of the disease. We report here that under our experimental conditions ram semen did not transmit infectivity to scrapie-susceptible transgenic mice overexpressing the V 136 R 154 Q 171 allele of the sheep prion (PRNP) gene. These results suggest that artificial insemination and natural mating have a very low or negligible potential for the transmission of scrapie in sheep flocks.

review the role played by environmental factors, such as ions, in the activation of sperm motilit... more review the role played by environmental factors, such as ions, in the activation of sperm motility and metabolism of different species of invertebrates and vertebrates. Special attention is given to changes in sperm internal pH, its regulation and role in the activation of sperm axonemal movement.

Journal of Cell Biology, 1992

European Journal of Biochemistry, 1987

For freshwater fish the motile period of sperm is extremely brief, even after a dilution in isoto... more For freshwater fish the motile period of sperm is extremely brief, even after a dilution in isotonic media. This result is in contrast to most other animals (ranging from invertebrates to mammals), in which sperm are generally motile for at least several hours.