Facteurs de croissance issus du cerveau : purification, stabilite, interactions avec heparine et molecules modeles

SIGLECNRS T 59829 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Urbanisation et qualité spermatique de la mésange charbonnière

L’urbanisation entraine des changements environnementaux rapides pouvant affecter le succès reproducteur chez les oiseaux. Peu d’études ont testé le lien avec un indicateur de la fertilité des mâles qu’est la qualité spermatique. Nous n’avons trouvé aucune différence en 2021 dans le succès d’éclosion chez les mésanges charbonnières entre des habitats urbanisés ou forestiers. Aucun paramètre de qualité spermatique n’était corrélé au succès d’éclosion. Néanmoins la longueur de la tête est significativement plus petite en ville, suggérant une vélocité plus importante

Does the Urban Environment Act as a Filter on the Individual Quality of Birds?

International audiencePhenotypic divergences of birds are common between urban and natural habitats and can result from different selective pressures between habitats or maladaptation to the city. No uniform patterns were observed, especially concerning markers of bird health, such as, for example, telomere length. Telomeres are involved in maintaining genome integrity and naturally shorten with age, but environmental stressors can accelerate their attrition. Thus, telomere length can be an indicator of individual quality. Some studies showed that urban breeders had longer telomeres than forest individuals. Two hypotheses can explain this result: (1) urban breeders are younger than forests breeders, and (2) cities act as a filter on individuals and only high-quality birds can successfully reproduce. In this context, we compared the age category (molting pattern) and morphological and physiological characteristics of urban and forest Great Tits before and during breeding. No differences in age or body condition were observed. However, urban breeders were smaller and had shorter telomeres than birds captured in winter. Urban birds had longer telomeres than forest birds, only in winter. These results highlight that urban habitats potentially favor smaller birds. However, the decrease in telomere length between winter and reproduction only in the city suggest a higher cost of reproduction in the city compared to the forest

Regulation of Clostridium tetani Neurotoxin Expression by Culture Conditions

BACKGROUND: Ensuring consistency of tetanus neurotoxin (TeNT) production by could help to ensure consistent product quality in tetanus vaccine manufacturing, ultimately contributing to reduced animal testing. The aim of this study was to identify RNA signatures related to consistent TeNT production using standard and non-standard culture&nbsp;conditions. METHODS: We applied RNA sequencing (RNA-Seq) to study gene expression in small-scale batches under several culture&nbsp;conditions. RESULTS: We identified 1381 time-dependent differentially expressed genes (DEGs) reflecting, among others, changes in growth rate and metabolism. Comparing non-standard versus standard culture conditions identified 82 condition-dependent DEGs, most of which were specific for one condition. The tetanus neurotoxin gene () was highly expressed but showed expression changes over time and between culture conditions. The gene showed significant down-regulation at higher pH levels (pH 7.8), which was confirmed by the quantification data obtained with the recently validated targeted LC-MS/MS&nbsp;approach. CONCLUSIONS: Non-standard culture conditions lead to different gene expression responses. The gene appears to be the best transcriptional biomarker for monitoring TeNT production as part of batch-to-batch consistency testing during tetanus vaccine&nbsp;manufacturing.</p

Reproductive differences between urban and forest birds across the years: importance of environmental and weather parameters

International audienceUrban environments pose many challenges to wildlife, not least for insectivorous passerines. Numerous studies have reported on the negative effects of urbanization on reproduction in these species. However, depending on the taxa and cities studied, no particular or positive effects have been reported. This may be related to the different levels of urban environmental stressors. As unfavorable weather can have deleterious effects on birds (e.g. lower prey availability and higher costs of pollutants), annual variations in the differences observed between sites could be related to synergetic effects between the urban environment and weather conditions. In this context, we studied the reproduction of great tit (Parus major) at two sites (urban and forest) over four years. First, we quantified pollution, prey availability, and vegetal cover at each site to characterize each environment. Second, we measured the effects of site and weather conditions on tit reproductive success to determine if the influence of weather is higher in the city. Except for the fledging rate, reproductive parameters were lower in the city than in the forest whatever the year probably because of poorer food availability and a predominance of non-vegetated areas in cities. The fledging rate and the nestling number in the urban environment were positively correlated to temperatures during rearing whereas there was no significant correlations in the forest. These results support the hypothesis of additive effects of urban constraints and weather that limit bird productivity in cities

Inter-annual variation of physiological traits between urban and forest great tits

International audienceUrbanization is characterized by rapid environmental changes such as an increase in building surface, in pollution, or a decrease in invertebrate abundance. For many bird species, morphological and physiological differences have been observed between urban and rural individuals that seem to reflect a negative impact of urban life on the health and fitness of individuals. Studies on passerine birds also showed important differences between populations and species in their responses to the urban environment. We propose to test physiological differences between urban and forest individuals over 3 years to understand whether the observed patterns are constant or subject to variations across years. For this purpose, we assessed the health parameters of adults and fledgling of great tits, Parus major, living in an urban and in a forest site in the Eurometropole of Strasbourg, for three years. Bird health was estimated with morphological parameters (body condition and size) and also with physiological parameters (oxidative status and telomere length). Our results showed lower body condition of urban fledglings regardless of the year, but no site effects on telomere length. On the contrary, for adult breeders, urban individuals had longer telomeres than forest ones except for one year which coincide with bad weather conditions during reproduction where no difference was detected. Urban birds also had higher antioxidant capacity whatever the years. These results suggest that cities act as a filter in which only good quality individuals survive and achieve successful reproduction regardless of year, whereas in the forest the selection occurs only during harsh weather years

Modern science for better quality control of medicinal products “Towards global harmonization of 3Rs in biologicals”: The report of an EPAA Workshop

This article summarizes the outcome of an international workshop organized by the European Partnership for Alternative Approaches to Animal Testing (EPAA) on Modern science for better quality control of medicinal products: Towards global harmonization of 3Rs in biologicals. As regards the safety testing of biologicals, the workshop participants agreed to actively encourage the deletion of abnormal toxicity tests and target animal batch safety tests from all relevant legal requirements and guidance documents (country-specific guidelines, pharmacopoeia monographs, WHO recommendations). To facilitate the global regulatory acceptance of non-animal methods for the potency testing of, e.g., human diphtheria and tetanus vaccines and veterinary swine erysipelas vaccines, international convergence on the scientific principles of the use of appropriately validated in vitro assays for replacing in vivo methods was recognized as a further means to unify regulatory approaches in different jurisdictions. It was recommended to include key regulators and manufacturers early in the corresponding discussions. Manufacturers and responsible expert groups, e.g. at the European Directorate for the Quality of Medicines and Health Care of the Council of Europe or the European Medicines Agency, were invited to consider leadership for international collaboration.JRC.F.3-Chemicals Safety and Alternative Method