Feline leukemia virus outbreak in the critically endangered Iberian lynx ( Lynx pardinus ): high-throughput sequencing of envelope variable region A and experimental transmission

The Iberian lynx is the most endangered felid species. During winter/spring 2006/7, a feline leukemia virus (FeLV) outbreak of unexpected virulence killed about 2/3 of the infected Iberian lynxes. All FeLV-positive animals were co-infected with feline hemoplasmas. To further characterize the Iberian lynx FeLV strain and evaluate its potential virulence, the FeLV envelope gene variable region A (VRA) mutant spectrum was analyzed using the Roche 454 sequencing technology, and an in vivo transmission study of lynx blood to specified-pathogen-free cats was performed. VRA mutations indicated weak apolipoprotein B mRNA editing enzyme and catalytic polypeptide-like cytidine deaminase (APOBEC) restriction of FeLV replication, and variants characteristic of aggressive FeLV strains, such as FeLV-C or FeLV-A/61C, were not detected. Cats exposed to FeLV/Candidatus Mycoplasma haemominutum-positive lynx blood did not show a particularly severe outcome of infection. The results underscore the special susceptibility of Iberian lynxes to infectious disease

Feline leukemia virus outbreak in the critically endangered Iberian lynx (Lynx pardinus): high-throughput sequencing of envelope variable region A and experimental transmission

The Iberian lynx is the most endangered felid species. During winter/spring 2006/7, a feline leukemia virus (FeLV) outbreak of unexpected virulence killed about 2/3 of the infected Iberian lynxes. All FeLV-positive animals were co-infected with feline hemoplasmas. To further characterize the Iberian lynx FeLV strain and evaluate its potential virulence, the FeLV envelope gene variable region A (VRA) mutant spectrum was analyzed using the Roche 454 sequencing technology, and an in vivo transmission study of lynx blood to specified-pathogen-free cats was performed. VRA mutations indicated weak apolipoprotein B mRNA editing enzyme and catalytic polypeptide-like cytidine deaminase (APOBEC) restriction of FeLV replication, and variants characteristic of aggressive FeLV strains, such as FeLV-C or FeLV-A/61C, were not detected. Cats exposed to FeLV/Candidatus Mycoplasma haemominutum-positive lynx blood did not show a particularly severe outcome of infection. The results underscore the special susceptibility of Iberian lynxes to infectious diseases

Utilisation des métallothionéines comme biomarqueur de la contamination métallique : variabilité entre sites et organes chez l'huı̂tre Crassostrea gigas

Heavy metals (Cd, Cu, Hg and Zn) and metallothionein levels were determined in oysters Crassostrea gigas from two sites: the Gironde Estuary (contaminated site) and Bourgneuf Bay (uncontaminated site). Metallothionein levels led us to suspect the presence of cadmium in the environment when quantified in the gills. Soluble cadmium and metallothioneins were positively correlated in the digestive gland of oysters from Gironde (contaminated site), but metallothionein levels in this organ were not significantly different from levels observed in the digestive gland of oysters from Bourgneuf Bay (uncontaminated site). Conversely, no correlation was noticed between metals and metallothioneins in the gills of oysters from Gironde despite metallothionein levels significantly higher than levels observed in oyster gills from Bourgneuf Bay. This significant difference of metallothionein levels is attributed to a higher ratio of soluble metals (Cd, Cu, Zn) in the gills of oysters from Gironde. The generalization of the use of metallothioneins as biomarkers of metal contamination of aquatic environments is questioned.Chez Crassostrea gigas, les teneurs en zinc, cuivre et cadmium dans les huı̂tres de Gironde sont significativement supérieures à celles des huı̂tres de la baie de Bourgneuf. Cadmium soluble et métallothionéines sont corrélés positivement dans la glande digestive des huı̂tres prélevées en Gironde (site contaminé). Pour autant, les teneurs en métallothionéines dans cet organe ne sont pas significativement différentes de celles d'huı̂tres de la baie de Bourgneuf (site de référence). À l'opposé, il n'y a pas de corrélation entre métaux et métallothionéines dans les branchies des huı̂tres de Gironde, mais leurs teneurs en métallothionéines sont significativement supérieures à celles des huı̂tres de la baie de Bourgneuf. L'augmentation significative des teneurs en métallothionéines est liée à une proportion plus importante des métaux (Cd, Cu, Zn) sous forme soluble dans les branchies des huı̂tres de Gironde. Chez l'huı̂tre Crassostrea gigas, les niveaux de métallothionéines dans les branchies permettent de préjuger de la présence de cadmium dans le milie

Exposition chronique au diclofénac de Lymnaea stagnalis, un gastéropode d'eau douce : Impact sur l'éclosion des embryons et sur la croissance des juvéniles

National audienceLe diclofénac est un anti-inflammatoire non stéroïdien largement utilisé en France, avec une vente de médicaments remboursés représentant 30 tonnes de principe actif en 2016. Cette molécule étant faiblement dégradée au niveau des stations d'épuration par les traitements classiques, elle fait partie des polluants émergents des milieux aquatiques. En effet, le diclofénac est retrouvé à des concentrations allant du ng/L au µg/L dans les eaux de surface, ce qui pourrait impacter la faune aquatique. Des études montrant un effet de ce médicament sur les organismes vivant en eau douce ont déjà été réalisées, cependant il reste nécessaire d'obtenir plus d'informations sur les conséquences à long terme du diclofénac aux concentrations environnementales. L’objectif de cette étude est de mieux caractériser les effets du diclofénac à long terme et à concentration environnementale sur Lymnaea stagnalis, un mollusque gastéropode d’eau douce. Le taux d’éclosion des pontes et la taille et le poids des juvéniles ont été mesurés

Molecular cloning of superoxide dismutase (Cu/Zn-SOD) from aquatic molluscs

The potential of the first line of the active oxygen-scavenging system, partial cDNA encoding Cu/Zn superoxide dismutase (SOD) was isolated in three aquatic mollusc species: Ruditapes decussatus (marine clam), Dreissena polymorpha (continental water mussel) and Bathymodiolus azoricus (hydrothermal vent mussel). These SOD cDNA fragments were amplified by PCR with degenerate oligonucleotide primers derived from the amino acid sequence conserved in the Cu/Zn-SOD from several other organisms. A partial cDNA of CuZn-SOD was obtained for R. decussates (510 bp), D. polymorpha (510 bp) and B. azoricus (195 bp). The deduced amino acid sequence showed high similarity among the three mollusc species (57-63%) and among other species (50-65%). The residues involved in coordinating copper (His-47, 49, 64, 121) and zinc (His-64, 72, 81 and Asp-84) were well conserved among the three Cu/Zn-SOD sequences.FCT (Fundação para Ciência e a Tecnologia) of the Ministry of Science and Technology of Portugalinfo:eu-repo/semantics/publishedVersio

Métabolisme des médicaments chez les organismes non-cibles : cas de l’exposition de Lymnaea stagnalis au diclofénac

International audienc

Effects of low-dose exposure to pesticide mixture on physiological responses of the pacific oyster, Crassostrea gigas

International audienceThis study investigated the effects on the physiology of Pacific oyster, Crassostrea gigas, of a mixture of pesticides containing 0.8 μg L-1 alachlor, 0.6 μg L-1 metolachlor, 0.7 μg L-1 atrazine, 0.6 μg L-1 terbuthylazine, 0.5 μg L-1 diuron, 0.6 μg L-1 fosetyl aluminum, 0.05 μg L-1 carbaryl, and 0.7 μg L-1 glyphosate for a total concentration of 4.55 μg L-1. The total nominal concentration of pesticides mixture corresponds to the pesticide concentrations in the shellfish culture area of the Marennes-Oleron basin. Two varieties of C. gigas were selected on the foreshore, based on their characteristics in terms of resistance to summer mortality, to assess the effects of the pesticide mixture after 7 days of exposure under controlled conditions. The early effects of the mixture were assessed using enzyme biomarkers of nitrogen metabolism (GS, glutamine synthetase), detoxification metabolism (GST, glutathione S-transferase), and oxidative stress (CAT, catalase). Sublethal effects on hemocyte parameters (phagocytosis and esterase activity) and DNA damages (DNA adducts) were also measured. Changes in metabolic activities were characterized by increases in GS, GST, and CAT levels on the first day of exposure for the "resistant" oysters and after 3-7 days of exposure for the "susceptible" oysters. The formation of DNA adducts was detected after 7 days of exposure. The percentage of hemocyte esterase-positive cells was reduced in the resistant oysters, as was the hemocyte phagocytic capacity in both oyster varieties after 7 days of exposure to the pesticide mixture. This study highlights the need to consider the low doses and the mixture of pesticides to evaluate the effects of these molecules on organisms. © 2011 Wiley Periodicals, Inc