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Effects of a sex ratio gradient on female mate-copying and choosiness in Drosophila melanogaster

Current Zoology 2018年第2期64卷 251-258页

作者： Magdalena MONIER Sabine NOBEL Guillaume ISABEL Etienne DANCHIN UMR-5174 Laboratoire Evolution & Diversite Biologique (EDB) Centre National de la Recherche Scientifique (CNRS) Institut de Recherche pour le Developpement (IRD) Universite de Toulouse 118 route de NarbonneF-31062 Toulouse Cedex 9 France Centre de Recherches sur la Cognition Animale (CRCA) Centre de Biologie Integrative (CBI) Centre National de la Recherche Scientifique (CNRS) Universite de Toulouse 118 route de Narbonne F-31082 Toulouse Cedex 9 France

In many sexually reproducing species, individuals can gather information about potential mates by observing their mating success. This behavioral pattern, that we call mate-copying, was reported in the fruit fly Drosophila rnelanogaster where females choosing between 2 males of contrasting phenotypes can build a preference for males of the phenotype they previously saw being chosen by a demonstrator female. As sex ratio is known to affect mate choice, our goal was to test whether mate-copying is also affected by encountered sex ratios. Thus, we created a gradient of sex ratio during demonstrations of mate-copying experiments by changing the number of females observ- ing from a central arena 6 simultaneous demonstrations unfolding in 6 peripheral compartments of a hexagonal device. We also tested whether the sex ratio experienced by females during demon- strations affected their choosiness （male courtship duration and double courtship rate） in subse- quent mate-choice tests. experimental male：female sex ratio during demonstrations did not affect mate-copying indices, but positively affected the proportion of both males courting the female during mate-choice tests, as well as male courtship duration, the latter potentially explaining the for- mer relationship. As expected, the sex ratio affected female choosiness positively, and Drosophila females seem to have evolved a mate-copying ability independently of sex ratio, and a capacity to adapt their choosiness to male availability. This suggests that, as in many animal species, individuals, especially females, can adapt their mate choice depending on the current sex ratio.

关键词： competition Drosophila melanogaster experimental protocol mate-copying social learning sex ratio.

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How rock samples can be representative of in situ condition:A case study of Callovo-Oxfordian claystones

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第4期10卷 613-623页

作者： N.Conil J.Talandier H.Djizanne R.de La Vaissière C.Righini-Waz C.Auvray C.Morlot G.Armand Andra URL BureFrance Andra Chatenay-MalabryFrance Universitéde Lorraine GéoRessources Vandoeuvre-les-NancyFrance

Within the framework of feasibility studies for a reversible, deep geological repository of high-and intermediate-level long-lived radioactive waste(HLW, IL-LLW), the French National Radioactive Waste Management Agency(Andra) is investigating the Callovo-Oxfordian(COx) formation near Bure(northeast part of France) as a potential host rock for the repository. The hydro-mechanical(HM) behaviour is an important issue to design and optimise different components of the disposal such as shaft, ramp, drift,and waste package disposal facilities. Over the past 20 years, a large number of laboratory experiments have been carried out to characterise and understand the HM behaviours of COx claystones. At the beginning, samples came from deep boreholes drilled at the ground surface with oil base mud. From2000 onwards, with the launch of the construction of the Meuse/Haute-Marne Underground Research Laboratory(MHM URL), most samples have been extracted from a large number of air drilled boreholes in the URL. In parallel, various constitutive models have been developed for modelling. The thermohydro-mechanical(THM) behaviours of the COx claystones were investigated under different repository conditions. Core samples are subjected to a complex HM loading path before testing, due to drilling, conditioning and preparation. Various kinds of effects on the characteristics of the claystones are highlighted and discussed, and the procedures for core extraction and packaging as well as a systematic sample preparation protocol are proposed in order to minimise the uncertainties on test results. The representativeness of the test results is also addressed with regard to the in situ rock mass.

关键词： Callovo-Oxfordian (COx) claystone samples Physical properties In situ condition Saturation degree Resaturation process experimental protocol

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Induction of pancreatic duct cells of neonatal rats into insulin-producing cells with fetal bovine serum: A natural protocol and its use for patch clamp experiments

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World Journal of Gastroenterology 2005年第44期11卷 6968-6974页

作者： San-Hua Leng Fu-Er Lu Institute of Integrative Traditional Chinese and Western Medicine Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 Hubei Province China

AIM： To induce the pancreatic duct cells into endocrine cells with a new natural protocol for electrophysiological study. METHODS： The pancreatic duct cells of neonatal rats were isolated, cultured and induced into endocrine ceils with 15% fetal bovine serum for a period of 20 d. During this period, insulin secretion, MTT value, and morphological change of neonatal and adult pancreatic islet cells were comparatively investigated. Pancreatic β-cells were identified by morphological and electrophysiological characteristics, while ATP sensitive potassium channels （KATP）, voltage-dependent potassium channels （Kv）, and voltage-dependent calcium channels （KcA） in β-cells were identified by patch clamp technique. RESULTS： After incubation with fetal bovine serum, the neonatal duct cells budded out, changed from duct-like cells into islet clusters. In the first 4 d, MTT value and insulin secretion increased slowly （MTT value from 0.024 ±0.003 to　3.028±0.003, insulin secretion from 2.6±0.6 to 3.1±0.8 mIU/L）. Then MTT value and insulin secretion increased quickly from d 5 to d 10 （MTT value from 0.028 ±0.003 to 0.052±0.008, insulin secretion from 3.1±0.8 to 18.3±2.6 mIU/L）, then reached high plateau （MTT value 〉0.052±0.008, insulin secretion 〉18.3±2.6 mIU/L）. In contrast, for the isolated adult pancreatic islet cells, both insulin release and MTT value were stable in the first 4 d （MTT value from 0.029±0.01 to 0.031±0.011, insulin secretion from 13.9±3.1 to 14.3±3.3 mIU/L）, but afterwards they reduced gradually （MTT value 〈0.031 ±0.011, insulin secretion 〈8.2±1.5 mIU/L）, and the pancreatic islet cells became dispersed, broken or atrophied correspondingly. The differentiated neonatal cells were identified as pancreatic islet cells by dithizone staining method, and pancreatic β-cells were further identified by both morphological features and electrophysiological characteristics, i.e. the existence of recording currents from KATP, Kv, and KCA. CONCLUSION： Islet cells different

关键词： Pancreatic duct cells Pancreatic precursor cells Insulin-producing cells Patch clamp experimental protocol ATP sensitive potassium channels Voltagedependent potassium channels Voltage-dependent calcium channels

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