MicroRNAs (miRNAs) constitute a new category of biomarkers. Studies on miRNAs in non-mammalian sp... more MicroRNAs (miRNAs) constitute a new category of biomarkers. Studies on miRNAs in non-mammalian species have drastically increased in the last few years. Here, we explored the use of miRNAs as potential, poorly-invasive markers, to identify sex and characterize acute stress in fish. The European seabass (Dicentrarchus labrax) was chosen as model because of its rapid response to stress and its specific sex determination system, devoid of sexual chromosomes. We performed a small RNA-sequencing analysis in the blood plasma of males and females’ European seabass (mature and immature) as well as in the blood plasma of juveniles submitted to an acute stress and sampled throughout the recovery period (at 0h, 0.5h, 1.5h and 6h). In immature individuals, both miR-1388-3p and miR-7132a-5p were up-regulated in females, while miR-499a-5p was more abundant in males. However, no miRNAs were found to be differentially expressed between sexes in the blood plasma of mature individuals. For the acute ...
Aquatic ecosystems can exhibit seasonal variation in resource availability and animals have evolv... more Aquatic ecosystems can exhibit seasonal variation in resource availability and animals have evolved to cope with the associated caloric restriction. During winter in the NW Mediterranean Sea, the European sardine Sardina pilchardus naturally experiences caloric restriction owing to a decrease in the diversity and quantity of plankton. However, ongoing global warming has had deleterious effects on plankton communities such that food shortages may occur throughout the year, especially under warm conditions in the summer. We investigated the interactive effects of temperature and food availability on sardine metabolism by continuously monitoring whole-animal respiration of groups of control (fed) and food-deprived sardines over a 60-day experiment in winter (12°C) or summer (20°C) conditions under natural photoperiod. In addition, we measured mitochondrial respiration of red muscle fibres, biometric variables and energy reserves of individuals sampled at 30 and 60 days. This revealed t...
Since 2008, there has been a major decrease in the numbers of old and large sardines in the Gulf ... more Since 2008, there has been a major decrease in the numbers of old and large sardines in the Gulf of Lions, which has had a major effect on regional fisheries. A bottom-up process involving a shift in diet towards smaller planktonic prey has been suggested as the main driver of this development. Yet, the reproductive capacities of the sardines have not changed, suggesting potential modifications in energy allocation trade-offs. Whether this could also affect maintenance, in particular at the end of the winter reproductive period, and explain the lower adult survival and the disappearance of older individuals remains unclear. We therefore experimentally investigated the consequences of seasonal food availability (summer vs. winter) on life-history traits and energy allocation trade-offs at the individual and population levels. Our results indicate that food resources during summer had a major effect on energy reserves and growth, limiting the maximum size and body condition reached at...
L’étude a été menée sur deux classes de poids (260-450g et 460-980 g) de dorades sauvages mainten... more L’étude a été menée sur deux classes de poids (260-450g et 460-980 g) de dorades sauvages maintenues à jeun en vivier pendant 40 jours après 3 semaines de captivité en cages sans alimentation. Au cours de cette phase de captivité les conditions de température ont progressivement évolué de 16.5 à 9.3 °C. Le taux de saturation en oxygène est resté supérieur à 95%. Les autres conditions de stockage ont été estimées non limitantes. Dans ce contexte, la perte de poids individuelle mesurée sur 2 lots de 30 individus de chaque classe de poids est de 3.7% pour les plus petits et de 3.3% pour les plus gros poissons
l'"dynomic: the food-demand structure is mointaine~ -Following the K.O., tlne same behav... more l'"dynomic: the food-demand structure is mointaine~ -Following the K.O., tlne same behavioral -+ it doesn't intensify social interactions to reoch Nl.1IflN.. ol1ll&!'t structure as the pre-removal situation is high food status """""'"' observed: new H-T fish appear and reach a -+ the new H-T fish actuate quickly the feeder and high food status without sign of competition distribute the some quantity of food as the H-T fish In ail tanks, the number of H-T fish remove.d. Also, the quantity of food delivered is removed =the number of new H-T fish adequate to the group size and to the fish biomass 90':'0 of the new H-T fish were IOI~ r gg,~r'ng \uoop_Clt ing that the H-T fish are able 1 ih before the K.O. :::0!'1 (,ofldi mPrl<:rlrp the global food needs.
MicroRNAs (miRNAs) constitute a new category of biomarkers. Studies on miRNAs in non-mammalian sp... more MicroRNAs (miRNAs) constitute a new category of biomarkers. Studies on miRNAs in non-mammalian species have drastically increased in the last few years. Here, we explored the use of miRNAs as potential, poorly-invasive markers, to identify sex and characterize acute stress in fish. The European seabass (Dicentrarchus labrax) was chosen as model because of its rapid response to stress and its specific sex determination system, devoid of sexual chromosomes. We performed a small RNA-sequencing analysis in the blood plasma of males and females’ European seabass (mature and immature) as well as in the blood plasma of juveniles submitted to an acute stress and sampled throughout the recovery period (at 0h, 0.5h, 1.5h and 6h). In immature individuals, both miR-1388-3p and miR-7132a-5p were up-regulated in females, while miR-499a-5p was more abundant in males. However, no miRNAs were found to be differentially expressed between sexes in the blood plasma of mature individuals. For the acute ...
Aquatic ecosystems can exhibit seasonal variation in resource availability and animals have evolv... more Aquatic ecosystems can exhibit seasonal variation in resource availability and animals have evolved to cope with the associated caloric restriction. During winter in the NW Mediterranean Sea, the European sardine Sardina pilchardus naturally experiences caloric restriction owing to a decrease in the diversity and quantity of plankton. However, ongoing global warming has had deleterious effects on plankton communities such that food shortages may occur throughout the year, especially under warm conditions in the summer. We investigated the interactive effects of temperature and food availability on sardine metabolism by continuously monitoring whole-animal respiration of groups of control (fed) and food-deprived sardines over a 60-day experiment in winter (12°C) or summer (20°C) conditions under natural photoperiod. In addition, we measured mitochondrial respiration of red muscle fibres, biometric variables and energy reserves of individuals sampled at 30 and 60 days. This revealed t...
Since 2008, there has been a major decrease in the numbers of old and large sardines in the Gulf ... more Since 2008, there has been a major decrease in the numbers of old and large sardines in the Gulf of Lions, which has had a major effect on regional fisheries. A bottom-up process involving a shift in diet towards smaller planktonic prey has been suggested as the main driver of this development. Yet, the reproductive capacities of the sardines have not changed, suggesting potential modifications in energy allocation trade-offs. Whether this could also affect maintenance, in particular at the end of the winter reproductive period, and explain the lower adult survival and the disappearance of older individuals remains unclear. We therefore experimentally investigated the consequences of seasonal food availability (summer vs. winter) on life-history traits and energy allocation trade-offs at the individual and population levels. Our results indicate that food resources during summer had a major effect on energy reserves and growth, limiting the maximum size and body condition reached at...
L’étude a été menée sur deux classes de poids (260-450g et 460-980 g) de dorades sauvages mainten... more L’étude a été menée sur deux classes de poids (260-450g et 460-980 g) de dorades sauvages maintenues à jeun en vivier pendant 40 jours après 3 semaines de captivité en cages sans alimentation. Au cours de cette phase de captivité les conditions de température ont progressivement évolué de 16.5 à 9.3 °C. Le taux de saturation en oxygène est resté supérieur à 95%. Les autres conditions de stockage ont été estimées non limitantes. Dans ce contexte, la perte de poids individuelle mesurée sur 2 lots de 30 individus de chaque classe de poids est de 3.7% pour les plus petits et de 3.3% pour les plus gros poissons
l'"dynomic: the food-demand structure is mointaine~ -Following the K.O., tlne same behav... more l'"dynomic: the food-demand structure is mointaine~ -Following the K.O., tlne same behavioral -+ it doesn't intensify social interactions to reoch Nl.1IflN.. ol1ll&!'t structure as the pre-removal situation is high food status """""'"' observed: new H-T fish appear and reach a -+ the new H-T fish actuate quickly the feeder and high food status without sign of competition distribute the some quantity of food as the H-T fish In ail tanks, the number of H-T fish remove.d. Also, the quantity of food delivered is removed =the number of new H-T fish adequate to the group size and to the fish biomass 90':'0 of the new H-T fish were IOI~ r gg,~r'ng \uoop_Clt ing that the H-T fish are able 1 ih before the K.O. :::0!'1 (,ofldi mPrl<:rlrp the global food needs.
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Papers by Gilbert Dutto