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21.
Micha?l Beaulieu Anne-Mathilde Thierry Yvon Le Maho Yan Ropert-Coudert André Ancel 《Journal of Ornithology》2009,150(3):637-643
We investigated alloparental interactions and conditions which could facilitate or prevent the expression of alloparental
behaviours in Adélie penguins (Pygoscelis adeliae), a long-lived seabird which nests in high-density colonies around Antarctica. Observation sessions were carried out during
the crèche stage on 48 identified pairs and 50 identified chicks in a 217-nest subcolony. As the season progressed, young
were fed less often by their own parents because these were increasingly absent from the breeding site and less responsive
to their offspring’s solicitations. As a consequence, young and particularly those with a low body mass, coming from a two-chick
brood, opted for gradually soliciting more from other adults to obtain food, preferentially those nesting in their direct
vicinity. Unsuccessful breeders represented a low and constant part of the adult population and were not specifically solicited
by unrelated young. Despite the increasing chick demand, only 4.1% (3 out of 73) of alloparental solicitations resulted in
feeding, which is negligible compared to parental feeding. To investigate factors that could trigger the appearance of alloparental
care, we carried out comparisons with king (Aptenodytes patagonicus) and emperor penguins (Aptenodytes forsteri) which represent the closest species for which data on alloparental behaviour were available. Our results show different
trends to those observed in these species and three factors may explain the low occurrence of alloparental behaviour in Adélie
penguins: (1) the low and constant proportion of unsuccessful breeders, (2) the absence of chick selectivity towards unsuccessful
breeders, and (3) the late period of chick accessibility for potential alloparents. 相似文献
22.
Ludivine Rousset Béatrice Alpha-Bazin Alice Château Jean Armengaud Thierry Clavel Odile Berge Catherine Duport 《Environmental microbiology》2020,22(12):5248-5264
Bacillus cereus is a ubiquitous endospore-forming bacterium, which mainly affects humans as a food-borne pathogen. Bacillus cereus can contaminate groundwater used to irrigate food crops. Here, we examined the ability of the emetic strain B. cereus F4810/72 to survive abiotic conditions encountered in groundwater. Our results showed that vegetative B. cereus cells rapidly evolved in a mixed population composed of endospores and asporogenic variants bearing spo0A mutations. One asporogenic variant, VAR-F48, was isolated and characterized. VAR-F48 can survive in sterilized groundwater over a long period in a vegetative form and has a competitive advantage compared to its parental strain. Proteomics analysis allowed us to quantify changes to cellular and exoproteins after 24 and 72 h incubation in groundwater, for VAR-F48 compared to its parental strain. The results revealed a significant re-routing of the metabolism in the absence of Spo0A. We concluded that VAR-F48 maximizes its energy use to deal with oligotrophy, and the emergence of spo0A-mutated variants may contribute to the persistence of emetic B. cereus in natural oligotrophic environments. 相似文献
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D. Abeck A.P. Johnson R.C. Ballard Y. Dangor E.A. Fontaine D. Taylor-Robinson 《FEMS microbiology letters》1987,48(3):397-399
Abstract A comparative study of the protein and lipopolysaccharide (LPS) profiles of 8 strains of Haemophilus ducreyi revealed that protein patterns remained unaffected by changes in medium composition, atmospheric conditions and temperature. In contrast, the LPS patterns exhibited marked variations under the different cultural conditions. 相似文献
25.
Gruber Véronique Berna Patrick P. Arnaud Thierry Bournat Philippe Clément Christèle Mison Dominique Olagnier Béatrice Philippe Laurence Theisen Manfred Baudino Sylvie Bénicourt Claude Cudrey Claire Bloës Carole Duchateau Nathalie Dufour Sylvie Gueguen Catherine Jacquet Séverine Ollivo Catherine Poncetta Christine Zorn Nathalie Ludevid Dolores Van Dorsselaer Alain Verger Robert Doherty Annette Mérot Bertrand Danzin Charles 《Molecular breeding : new strategies in plant improvement》2001,7(4):329-340
A recombinant dog gastric lipase with therapeutic potential for the treatment of exocrine pancreatic insufficiency was expressed in transgenic tobacco plants. We targeted the protein using two different signal sequences for either vacuolar retention or secretion. In both cases, an active glycosylated recombinant protein was obtained. The recombinant enzymes and the native enzyme displayed similar properties including acid resistance and acidic optimum pH. The proteolytic maturation and the specific activity of the recombinant proteins, however, were found to be dependent on subcellular compartmentalization. Expression levels of recombinant dog gastric lipase were about 5% and 7% of acid extractable plant proteins for vacuolar retention and secretion respectively. This expression system already has allowed the production of tens of grams of purified lipase through open-field culture of transgenic tobacco plants. 相似文献
26.
Single-Cell Multiomics: Multiple Measurements from Single Cells 总被引:1,自引:0,他引:1
27.
Plant functional traits are increasingly used in restoration ecology because they have the potential to guide restoration practices at a broad scale. This article presents a trait‐based multi‐criteria framework to evaluate and predict the performance of 17 plant seedlings to improve ecological restoration of marly eroded areas in the French Southern Alps. The suitability of these species to limit soil erosion was assessed by studying both their response to erosive forces and their effect on erosion dynamics. We assumed that species efficiency could be explained and predicted from plant traits and we looked for trait‐performance relationships. Our results showed that root slenderness ratio, the percentage of fine roots and root system topology, were the three root morphology traits best describing anchorage strength. Root system characterized by a long and thin tap root and many fine lateral ramifications would be the best to resist concentrated runoff. Species response to burial mainly depended on growth form and morphological flexibility. The abilities of species in reinforcing the soil and reducing erosion rates were negatively correlated to root diameter and positively to the percentage of fine roots. Moreover, root system density and root tensile strength also influenced root reinforcement. Finally, the ability to trap sediment was positively correlated to leaf area and canopy density. Species were then scored and classified in four clusters according to their global performance. This method allows identifying species that possess both response and effect traits related to the goal of preventing erosion during ecological restoration. 相似文献
28.
Combined analysis of Perca fluviatilis reproductive performance and oocyte proteomic profile 总被引:1,自引:0,他引:1
Castets MD Schaerlinger B Silvestre F Gardeur JN Dieu M Corbier C Kestemont P Fontaine P 《Theriogenology》2012,78(2):432-442
The success of reproduction depends greatly upon gamete quality, especially oocytes which carry most of the molecular material necessary for early embryogenesis. However, it remains difficult to find relevant morphologic and/or biochemical parameters to assess oocyte quality and thus have a reliable prediction of the reproduction performance. To understand which criteria are the most reliable to assess the reproductive success of the Eurasian perch (Perca fluviatilis), we measured 14 parameters characterizing female, spawn, oocyte, and embryonic or larval development on 20 independent spawn. A data analysis allowed the definition of two clusters of spawn with different larval characteristics: the first cluster was composed of spawn which led mainly to strong large larvae presenting a low deformity rate, while the second cluster rather corresponds to spawn leading to smaller and weaker larvae with a higher deformity rate. Moreover, a third cluster (unfertilized spawn) was studied. Our analysis revealed that most of the prefertilization biological traits that we studied appeared poorly relevant to predict larval features, proper embryonic development and deformity occurrences. We thus performed a large scale proteomic analysis to highlight proteins differently expressed in each spawn cluster. A 2D-DIGE study followed by an MS/MS spectrometry allowed the identification of 32 proteins involved in several biological functions and differently expressed between spawn clusters. Among them, proteins involved in cell response to the oxidative stress, as well as energetic metabolism, heat shock proteins and Vitellogenins are of particular interest. Several functions appear specific to a spawn cluster and could thus explain their corresponding reproduction performance. In the future, proteins involved in those cellular mechanisms may constitute molecular markers predictive of the reproduction performance in Perca fluviatilis. 相似文献
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