POPULATION MODELING AS AID TO RODENT CONTROL IN THE FIELD

Forecasting the damages by voles on plant crops depends on a good forecast of vole population density. Biological work in Vendee from 1959 till 1968 have furnished the fundamentals of a population model. Further work on the relationship between breeding and climate enabled us to set up a practical forecasting model. This is applied by the Plant Protection Service, and the damage prevention system consists of a test trapping in winter, a population forecasting in early March, and, if necessary, poisoning in March-April. Generalization of the system is in progress

Évaluation des dépenses énergétiques au quotidien chez les ongulés sauvages in natura : analyse bibliographique des éléments disponibles pour une approche additive

Les dépenses énergétiques des ongulés sauvages in natura doivent souvent être quantifiées par une approche indirecte qui les décompose en coûts : (i) de base, (ii) de thermorégulation, (iii) d'alimentation, (iv) de posture debout et d'activité, (v) de croissance et de reproduction. Les dépenses « au quotidien », objet de cette synthèse, correspondent aux quatre premiers compartiments; les données bibliographiques correspondantes, mesures, estimations et prédictions, sont rapportées et comparées; leurs conditions et limites d'utilisation sont discutées. Le niveau de base (sans thermorégulation, ni activité) devrait être estimé par le métabolisme dit « Standard » ou « de Base », délicat à mesurer, même en laboratoire, sur les animaux sauvages. C'est pourquoi d'autres estimations, plus ou moins assimilables à un métabolisme dit « de Repos », sont habituellement utilisées, bien que cette approche puisse être considérée comme moins rigoureuse. La formule de Kleiber (1961) prédit le métabolisme standard d'animaux adultes, Mammifères et Oiseaux principalement, en fonction de leur masse corporelles; des prédictions plus précises ont été mises au point, mais pour des catégories (d'espèce, d'âge, de sexe,...) particulières. La thermorégulation est le résultat d'interactions complexes entre diverses caractéristiques environnementales (température ambiante, humidité, vitesse du vent, rayonnement solaire) et de multiples paramètres relatifs à l'animal (surface offerte, isolation corporelle, état physiologique...). Si son coût peut être considéré comme nul à l'intérieur de ce qu'on appelle « zone de neutralité thermique » (ZNT), il augmente de part et d'autre, via la mise en œuvre de mécanismes physiologiques, chimiques et comportementaux très divers qui interviennent pour maintenir une température corporelle acceptable. Les expérimentations permettant de déterminer la nature et le coût des mécanismes mis en oeuvre exigent des sujets entraînés et un dispositif expérimental assez lourd; la transposition qualitative aux animaux libres en nature est, dans une certaine mesure, possible, la transposition quantitative est difficile. Le coût total d'alimentation inclut les coûts de posture debout et de recherche alimentaire, ainsi que ceux, plus spécifiques, de prise alimentaire (i.e. prélèvement, mastication, déglutition), de digestion et éventuellement de rumination. La nature de l'aliment peut certes, chez tous les ongulés, influer assez fortement sur le coût de prise alimentaire, mais ce sont les déplacements liés à la recherche alimentaire qui génèrent les dépenses les plus importantes chez les animaux sauvages en nature. Les coûts de posture debout et de locomotion (composantes essentielles de l'activité) ont été quantifiés chez de nombreuses espèces en comparant le métabolisme d'animaux debout et/ou en déplacement à celui d'animaux couchés. A partir de ces mesures, certains auteurs, Taylor et al. (1982) en particulier, ont proposé des formules prédictives pour évaluer le coût de locomotion en fonction de la masse corporelle. Des estimations de surcoût pour les déplacements en terrain difficile (pente, obstacles, neige, boue) ont également été rapportées. L'approche additive reste une modélisation dont la validité dépend largement de la qualité des estimations de dépenses disponibles et de la précision des paramètres d'activité recueillis sur les animaux cibles.Estimating the energy expenditures of wild ungulates in natura often requires an indirect approach splitting them within: (i) basal level, (ii) thermoregulation cast, (iii) feeding cast, (iv) standing and activity cast, (v) growth and reproduction cast. First, each of the costs can be measured (most often through respirometric technics) or estimated (from previously obtained values). Second, these amounts are summed up ("additive" approach) according to the activity budget of the animal. The present bibliographie review only deals with daily expenditures, namely costs (i) to (iv). Various measures (with comparative tables), estimations and [allometric] predictive equations are reported, and their accuracy and limits are discussed. Basal level (without thermoregulation and activity) should be estimated by Standard or Basal Metabolic Rate, but this is difficult to measure on wild animals, even in the laboratory. Other estimations, more or less close to Resting Metabolic Rate (RMR) are therefore often used, although they are Jess relevant. Kleiber' s equation (196 1 ) predicts the standard metabolism of adult animals, mainly mammals and birds, from their body mass; some more accurate models are available but for more limited species, age, sex, ... categories. Thermoregulation is the result of complex interactions between various environmental (air temperature, moisture, wind speed, solar radiation . . . ) and animal (body area, insulation, physiological condition, . . . ) parameters. Therefore, it is not possible to give more or less standardized costs as for other expenditures. Thermoregulation cast can be considered as null in the so called "Thermoneutral Zone, TNZ". It increases outside this zone because of various physiological, chemical and behavioural mechanisms acting to maintain acceptable deep body temperature. Determining the nature and measuring the cast of the involved mechanisms (which vary according to species, season, age and physical condition of animals) require experiments on trained animals and an heavy experimental device. Qualitative extent to ungulates in natura is somewhat possible, but quantitative extent is difficult. Total feeding cast includes standing and moving (food search) costs, and some more typical costs: "eating" (i.e. prehension, mastication and swallowing), digestion and possibly rumination. In all (domestic or wild) ungulates, the type of food consumed can modify the eating cast, but foraging trips (more or Jess inversely related to food availability) can obviously involve the most important incremental costs in wild ungulates. Standing and locomotion costs (the main components of activity costs) were quantified in various species by comparing the metabolism of lying, standing and moving animals. From these measures, some authors (particularly Taylor et al., 1982) modeled locomotion cast from body mass. Some estimations of incremental costs due to a difficult terrain (slope, obstacles, snow caver, mud) are also reported. The relevance of the additive approach in energetic studies mainly relies on the quality of the available measures or estimations of each cost and on the accuracy of the activity parameters that are obtained from target animals. Of the various expenditure components, locomotion appears to be the most suitable for comparative purposes; however, the accurate estimation of its cost requires data adequate to identify the right terrain used by the animals

HYENA detects oncogenes activated by distal enhancers in cancer

Somatic structural variations (SVs) in cancer can shuffle DNA content in the genome, relocate regulatory elements, and alter genome organization. Enhancer hijacking occurs when SVs relocate distal enhancers to activate proto-oncogenes. However, most enhancer hijacking studies have only focused on protein-coding genes. Here, we develop a computational algorithm ‘HYENA’ to identify candidate oncogenes (both protein-coding and non-coding) activated by enhancer hijacking based on tumor whole-genome and transcriptome sequencing data. HYENA detects genes whose elevated expression is associated with somatic SVs by using a rank-based regression model. We systematically analyze 1146 tumors across 25 types of adult tumors and identify a total of 108 candidate oncogenes including many non-coding genes. A long non-coding RNA TOB1-AS1 is activated by various types of SVs in 10% of pancreatic cancers through altered 3-dimensional genome structure. We find that high expression of TOB1-AS1 can promote cell invasion and metastasis. Our study highlights the contribution of genetic alterations in non-coding regions to tumorigenesis and tumor progression

Signals from the brain and olfactory epithelium control shaping of the mammalian nasal capsule cartilage

Facial shape is the basis for facial recognition and categorization. Facial features reflect the underlying geometry of the skeletal structures. Here, we reveal that cartilaginous nasal capsule (corresponding to upper jaw and face) is shaped by signals generated by neural structures: brain and olfactory epithelium. Brain-derived Sonic Hedgehog (SHH) enables the induction of nasal septum and posterior nasal capsule, whereas the formation of a capsule roof is controlled by signals from the olfactory epithelium. Unexpectedly, the cartilage of the nasal capsule turned out to be important for shaping membranous facial bones during development. This suggests that conserved neurosensory structures could benefit from protection and have evolved signals inducing cranial cartilages encasing them. Experiments with mutant mice revealed that the genomic regulatory regions controlling production of SHH in the nervous system contribute to facial cartilage morphogenesis, which might be a mechanism responsible for the adaptive evolution of animal faces and snouts

Local retinoic acid signaling directs emergence of the extraocular muscle functional unit

Coordinated development of muscles, tendons, and their attachment sites ensures emergence of functional musculoskeletal units that are adapted to diverse anatomical demands among different species. How these different tissues are patterned and functionally assembled during embryogenesis is poorly understood. Here, we investigated the morphogenesis of extraocular muscles (EOMs), an evolutionary conserved cranial muscle group that is crucial for the coordinated movement of the eyeballs and for visual acuity. By means of lineage analysis, we redefined the cellular origins of periocular connective tissues interacting with the EOMs, which do not arise exclusively from neural crest mesenchyme as previously thought. Using 3D imaging approaches, we established an integrative blueprint for the EOM functional unit. By doing so, we identified a developmental time window in which individual EOMs emerge from a unique muscle anlage and establish insertions in the sclera, which sets these muscles apart from classical muscle-to-bone type of insertions. Further, we demonstrate that the eyeballs are a source of diffusible all-trans retinoic acid (ATRA) that allow their targeting by the EOMs in a temporal and dose-dependent manner. Using genetically modified mice and inhibitor treatments, we find that endogenous local variations in the concentration of retinoids contribute to the establishment of tendon condensations and attachment sites that precede the initiation of muscle patterning. Collectively, our results highlight how global and site-specific programs are deployed for the assembly of muscle functional units with precise definition of muscle shapes and topographical wiring of their tendon attachments

Functional Assessment of Disease-Associated Regulatory Variants <i>In Vivo</i> Using a Versatile Dual Colour Transgenesis Strategy in Zebrafish

Disruption of gene regulation by sequence variation in non-coding regions of the genome is now recognised as a significant cause of human disease and disease susceptibility. Sequence variants in cis-regulatory elements (CREs), the primary determinants of spatio-temporal gene regulation, can alter transcription factor binding sites. While technological advances have led to easy identification of disease-associated CRE variants, robust methods for discerning functional CRE variants from background variation are lacking. Here we describe an efficient dual-colour reporter transgenesis approach in zebrafish, simultaneously allowing detailed in vivo comparison of spatio-temporal differences in regulatory activity between putative CRE variants and assessment of altered transcription factor binding potential of the variant. We validate the method on known disease-associated elements regulating SHH, PAX6 and IRF6 and subsequently characterise novel, ultra-long-range SOX9 enhancers implicated in the craniofacial abnormality Pierre Robin Sequence. The method provides a highly cost-effective, fast and robust approach for simultaneously unravelling in a single assay whether, where and when in embryonic development a disease-associated CRE-variant is affecting its regulatory function

Population modeling as aid to rodent control in the field

Forecasting the damages by voles on plant crops depends on a good forecast of vole population density. Biological work in Vendee from 1959 til 1968 has furnished the fundamentals of a population model. Further work on the relationship between breeding and climate enabled us to set up a practical forecasting model. This is applied by the Plant Protection Service, and the damage prevention system consists of a test trapping in winter, a population forecasting in early March, and, if necessary, poisoning in March-April. Generalization of the system is in progress

Global Control Regions and Regulatory Landscapes in Vertebrate Development and Evolution

During the course of evolution, many genes that control the development of metazoan body plans were co-opted to exert novel functions, along with the emergence or modification of structures. Gene amplification and/or changes in the cis- regulatory modules responsible for the transcriptional activity of these genes have certainly contributed in a major way to evolution of gene functions. In some cases, these processes led to the formation of groups of adjacent genes that appear to be controlled by both global and shared mechanisms

Cyclic fluctuations of microtine populations: half a century of research

Numerous microtine populations show important cyclic fluctuations of density which have aroused many scientific works, mostly since the fifties. Intrinsic mechanisms (densitydependence, genetic selection) and extrinsic mechanisms (predation, interaction with trophic resources) were both involved for building hypotheses. The present paper gives a survey of the different investigations developed in this field and a review of the mechanisms supposedly involved in population fluctuations. As a conclusion we try to build a synthetic diagram showing the place and the role of the various regulating factors, and their interactionsLes populations de nombreuses espèces de campagnols montrent des fluctuations importantes à caractère cyclique qui ont suscité de nombreux travaux de recherche, surtout depuis les années 1950. Les hypothèses de recherche ont porté aussi bien sur des facteurs de régulation tant intrinsèques (mécanismes dépendant de la densité, sélection génétique) qu'extrinsèques (action des ressources ou des prédateurs). Nous nous proposons dans cette synthèse de faire un récapitulatif des démarches de recherche qui ont gravité autour de ce thème en passant en revue les mécanismes supposés être la cause des fluctuations des populations. Nous tentons in fine, dans un schéma synthétique, de réévaluer le rôle des principaux facteurs de régulation selon les phases du cycle d'abondance et de montrer la complexité de leurs interactions