Behavioral phenotyping of rodents

Established methods for analyzing behavioral traits in mutant lines of mice allow researchers to understand the outcomes of genetic manipulations in the nervous system. A rigorous six-tiered behavioral phenotyping strategy is described. Recommendations are offered for the design of mouse behavioral testing suites in animal housing facilities.     

Embryonic and neonatal phenotyping of genetically engineered mice

Considerable progress has been made in adapting existing and developing new technologies to enable increasingly detailed phenotypic information to be obtained in embryonic and newborn mice. Sophisticated methods for imaging mouse embryos and newborns are available and include ultrasound and magnetic resonance imaging (MRI) for in vivo imaging, and MRI, vascular corrosion casts, micro-computed tomography, and optical projection tomography (OPT) for postmortem imaging. In addition, Doppler and M-mode ultrasound are useful noninvasive tools to monitor cardiac and vascular hemodynamics in vivo in embryos and newborns. The developmental stage of the animals being phenotyped is an important consideration when selecting the appropriate technique for anesthesia or euthanasia and for labeling animals in longitudinal studies. Study design also needs to control for possible differences between inter- and intralitter variability, and for possible long-term developmental effects caused by anesthesia and/or procedures. Noninvasive or minimally invasive intravenous or intracardiac injections or blood sampling, and arterial pressure and electrocardiography (ECG) measurements are feasible in newborns. Whereas microinjection techniques are available for embryos as young as 6.5 days of gestation, further advances are required to enable minimally invasive fluid or tissue samples, or blood pressure or ECG measurements, to be obtained from mouse embryos in utero. The growing repertoire of techniques available for phenotyping mouse embryos and newborns promises to accelerate knowledge gained from studies using genetically engineered mice to understand molecular regulation of morphogenesis and the etiology of congenital diseases.     

昆虫学研究的Internet资源

互联网的发展给昆虫学的研究开辟了新的道路。该文简要介绍了Internet以及在昆虫学研究和教学中的应用概况 ,并从虚拟图书馆、数据库、在线工具、网上期刊、课程网站以及个人网页 6个方面系统介绍了昆虫学研究的Internet资源     

Internet resources for the human geneticist

The Internet is a massive expanding body of information, which is likely to play a significant role for clinicians and researchers across the world. Since its inception in December 1969 the Internet has grown rapidly and is anticipated to expand 1,000% in the coming next few years. Various useful databases on human genetics are already in 'the Net' and many more are being added constantly. The future of human geneticist is in handling of information. In this review of Internet and compilation of important web site addresses we expect to stimulate and instruct human geneticists in navigating the Net. The list of web sites provided in this article is expected to facilitate their search.     

In-depth metabolic phenotyping of genetically engineered mouse models in obesity and diabetes

The world-wide prevalence of obesity and diabetes has increased sharply during the last two decades. Accordingly, the metabolic phenotyping of genetically engineered mouse models is critical for evaluating the functional roles of target genes in obesity and diabetes, and for developing new therapeutic targets. In this review, we discuss the practical meaning of metabolic phenotyping, the strategy of choosing appropriate tests, and considerations when designing and performing metabolic phenotyping in mice.     

Cause and effect considerations in diagnostic pathology and pathology phenotyping of genetically engineered mice (GEM)

Over the next several decades, biology is embarking on its most ambitious project yet: to annotate the human genome functionally, prioritizing and focusing on those genes relevant to development and disease. Model systems are fundamental prerequisites for this task, and genetically engineered mice (GEM) are by far the most accessible mammalian system because of their anatomical, physiological, and genetic similarity to humans. The scientific utility of GEM has become commonplace since the technology to produce them was established in the early 1980s. Conceptually, however, an efficiently coordinated high-throughput approach that permits correlation between newly discovered genes, functional properties of their protein products, and biological relevance of these products as drug targets has yet to be established. The discipline of veterinary anatomical pathology (hereafter referred to as pathology) is not immune to this requirement for evolution and adaptation, and to address relationships and tissue consequences between tens of thousands of genes and their cognate proteins, novel interdisciplinary technologies and approaches must emerge. Although many of the techniques of pathology are well established, in the context of pathology's contribution to functional annotation of the genome, several conceptually important and unresolved issues remain to be addressed. While an ever-increasing arsenal of genetic and molecular tool-sets are available to evaluate and understand the function of genes and their pathophysiological mechanisms, pathology will continue to play an essential role in confirming cause and effect relationships of gene function in development and disease. This role will continue to be dependent on keen observation, a systematic but disciplined approach, expert knowledge of strain-dependent anatomical differences and incidental lesions, and relevant tissue-based evidence. Miniaturization and high-throughput adaptation of these methods must also continue so that they can complement parallel phenotyping efforts, provide pathology-based data in pace with concurrent phenotyping efforts, and continue to find new utility in the collective effort of functional annotation.     

An improved method for butyrylcholinesterase phenotyping

An improved method for the identification of butyrylcholinesterase phenotypes is proposed. It is based on modifications of a method that uses -naphthyl acetate as substrate anddl-propranolol and Ro2-0683 as inhibitors. The proposed modifications make the method more rapid and increase the accuracy of the determinations of the phenotypes tested (BCHE U, BCHE UF, BCHE UA, BCHE AK, BCHE AF, and BCHE A). These modifications make the method even more adequate for population studies and clinical routine.We are grateful to the CNPq for research grants and scholarships.A preliminary report was presented at the Third International Meeting on Cholinesterases, France, May 12–16, 1990.     

Behavioral phenotyping strategies for mutant mice

Comprehensive behavioral analyses of transgenic and knockout mice have successfully identified the functional roles of many genes in the brain. Over the past 10 years, strategies for mouse behavioral phenotyping have evolved to maximize the scope and replicability of findings from a cohort of mutant mice, minimize the interpretation of procedural artifacts, and provide robust translational tools to test hypotheses and develop treatments. This Primer addresses experimental design issues and offers examples of high-throughput batteries, learning and memory tasks, and anxiety-related tests.     

Production of fuels and chemicals from renewable resources using engineered Escherichia coli

Biotechnological production of fuels and chemicals from renewable resources is an appealing way to move from the current petroleum-based economy to a biomass-based green economy. Recently, the feedstocks that can be used for bioconversion or fermentation have been expanded to plant biomass, microbial biomass, and industrial waste. Several microbes have been engineered to produce chemicals from renewable resources, among which Escherichia coli is one of the best studied. Much effort has been made to engineer E. coli to produce fuels and chemicals from different renewable resources. In this paper, we focused on E. coli and systematically reviewed a range of fuels and chemicals that can be produced from renewable resources by engineered E. coli. Moreover, we proposed how can we further improve the efficiency for utilizing renewable resources by engineered E. coli, and how can we engineer E. coli for utilizing alternative renewable feedstocks. e.g. C1 gases and methanol. This review will help the readers better understand the current progress in this field and provide insights for further metabolic engineering efforts in E. coli.     

Mouse phenotyping

Model organisms like the mouse are important tools to learn more about gene function in man. Within the last 20 years many mutant mouse lines have been generated by different methods such as ENU mutagenesis, constitutive and conditional knock-out approaches, knock-down, introduction of human genes, and knock-in techniques, thus creating models which mimic human conditions. Due to pleiotropic effects, one gene may have different functions in different organ systems or time points during development. Therefore mutant mouse lines have to be phenotyped comprehensively in a highly standardized manner to enable the detection of phenotypes which might otherwise remain hidden. The German Mouse Clinic (GMC) has been established at the Helmholtz Zentrum München as a phenotyping platform with open access to the scientific community (www.mousclinic.de; [1]). The GMC is a member of the EUMODIC consortium which created the European standard workflow EMPReSSslim for the systemic phenotyping of mouse models (http://www.eumodic.org/ [2]).     

Nested effects models for high-dimensional phenotyping screens

MOTIVATION: In high-dimensional phenotyping screens, a large number of cellular features is observed after perturbing genes by knockouts or RNA interference. Comprehensive analysis of perturbation effects is one of the most powerful techniques for attributing functions to genes, but not much work has been done so far to adapt statistical and computational methodology to the specific needs of large-scale and high-dimensional phenotyping screens. RESULTS: We introduce and compare probabilistic methods to efficiently infer a genetic hierarchy from the nested structure of observed perturbation effects. These hierarchies elucidate the structures of signaling pathways and regulatory networks. Our methods achieve two goals: (1) they reveal clusters of genes with highly similar phenotypic profiles, and (2) they order (clusters of) genes according to subset relationships between phenotypes. We evaluate our algorithms in the controlled setting of simulation studies and show their practical use in two experimental scenarios: (1) a data set investigating the response to microbial challenge in Drosophila melanogaster, and (2) a compendium of expression profiles of Saccharomyces cerevisiae knockout strains. We show that our methods identify biologically justified genetic hierarchies of perturbation effects. AVAILABILITY: The software used in our analysis is freely available in the R package 'nem' from www.bioconductor.org.