Publications by authors named "Robert Bunet"

The fan mussel is currently on the brink of extinction due to a multifactorial disease mainly caused to the highly pathogenic parasite , meaning that the selection pressure outweighs the adaptive potential of the species. Hopefully, rare individuals have been observed somehow resistant to the parasite, stretching the need to identify the traits underlying this better fitness. Among the candidate to explore at first intention are fast-evolving immune genes, of which toll-like receptor (TLR).

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With the intensification of maritime traffic, recently emerged infectious diseases have become major drivers in the decline and extinction of species. Since 2016, mass mortality events have decimated the endemic Mediterranean Sea bivalve Pinna nobilis, affecting ca. 100% of individuals.

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Background: The pen shells Pinna nobilis and Pinna rudis are large wedge-shaped bivalve molluscs. Both species are threatened by different anthropogenic pressures. In the last few years, P.

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Poly(dimethylsiloxane) (PDMS) elastomer coatings containing an amphiphilic hydrolyzable diblock copolymer additive were prepared and their potential as marine antifouling and antiadhesion materials was tested. The block copolymer additive consisted of a PDMS first block and a random poly(trialkylsilyl methacrylate (TRSiMA, R = butyl, isopropyl)--poly(ethyleneglycol) methacrylate (PEGMA) copolymer second block. PDMS--TRSiMA block copolymer additives without PEGMA units were also used as additives.

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Article Synopsis
  • 17α-ethinylestradiol (EE2), a component of female contraceptive pills, has been found in Mediterranean coasts impacting seahorse populations, particularly Hippocampus guttulatus.
  • Research exposed 2-month-old, undifferentiated seahorses to 21 ng/L of EE2 for 30 days, resulting in a 19% weight reduction and a 27% mortality rate, alongside demasculinization in males.
  • The exposure affected hormone levels, decreasing estradiol and testosterone in males while leading to unexpectedly lower vitellogenin in females, highlighting growth and maturation issues linked to this environmental contaminant.
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Fouling Release Coatings are marine antifouling coatings based on silicone elastomers. Contrary to commonly used biocide-based antifouling coatings, they do not release biocides into the marine environment, however, they suffer from poor antifouling efficacy during idle periods. To improve their antifouling performances in static conditions, various amounts of hydrolyzable polymers were incorporated within a silicone matrix.

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The phosphopantetheinyl transferases (PPTases) are responsible for the activation of the carrier protein domains of the polyketide synthases (PKS), non ribosomal peptide synthases (NRPS) and fatty acid synthases (FAS). The analysis of the Streptomyces ambofaciens ATCC23877 genome has revealed the presence of four putative PPTase encoding genes. One of these genes appears to be essential and is likely involved in fatty acid biosynthesis.

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Glyphosate-based herbicides are the most frequently used herbicides in the world. We evaluated the effect of Roundup 360 SL on the expression of interleukin-1β (il-1β), interleukin-10 (il-10) and heme-oxygenase-1 (ho-1) in the gills, intestines and spleen of young European sea bass (Dicentrachus labrax L.), aged 8 mo.

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Background: The control of antibiotic production in Streptomyces coelicolor A3(2) involves complicated regulatory networks with multiple regulators controlling the expression of antibiotic biosynthetic pathways. One such regulatory network is that of the γ-butyrolactones, the so-called S. coelicolor butanolide (SCB) system.

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The genome sequence of Streptomyces ambofaciens, a species known to produce the congocidine and spiramycin antibiotics, has revealed the presence of numerous gene clusters predicted to be involved in the biosynthesis of secondary metabolites. Among them, the type II polyketide synthase-encoding alp cluster was shown to be responsible for the biosynthesis of a compound with antibacterial activity. Here, by means of a deregulation approach, we gained access to workable amounts of the antibiotics for structure elucidation.

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gamma-Butyrolactone bacterial hormones regulate antibiotic production and morphological differentiation in Streptomyces species. One gamma-butyrolactone, SCB1, has been previously characterized in Streptomyces coelicolor. Here we report the characterization of two additional gamma-butyrolactones, named SCB2 (2-[1'-hydroxyoctyl]-3-hydroxymethylbutanolide) and SCB3 (2-[1'-hydroxy-6'-methyloctyl]-3-hydroxymethylbutanolide), possessing an antibiotic stimulatory activity.

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Streptomyces ambofaciens produces an orange pigment and the antibiotic alpomycin, both of which are products of a type II polyketide synthase gene cluster identified in each of the terminal inverted repeats of the linear chromosome. Five regulatory genes encoding Streptomyces antibiotic regulatory proteins (alpV, previously shown to be an essential activator gene; alpT; and alpU) and TetR family receptors (alpZ and alpW) were detected in this cluster. Here, we demonstrate that AlpZ, which shows high similarity to gamma-butyrolactone receptors, is at the top of a pathway-specific regulatory hierarchy that prevents synthesis of the alp polyketide products.

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The potential iron siderophore transporter genes have been determined from the genome sequence of Streptomyces coelicolor A3(2). One of these gene clusters, cdtABC, was disrupted and characterized to determine its role in the uptake of the siderophores produced by S. coelicolor.

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The duplicated hasR and hasL genes of Streptomyces ambofaciens encode alternative sigma factors (named sigma(B(R)) and sigma(B(L))) belonging to the sigma(B) general stress response family in Bacillus subtilis. The duplication appears to be the result of a recent event that occurred specifically in S. ambofaciens.

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