Lipid metabolism, adipocyte depot physiology and utilization of meat animals as experimental models for metabolic research

Meat animals are unique as experimental models for both lipid metabolism and adipocyte studies because of their direct economic value for animal production. This paper discusses the principles that regulate adipogenesis in major meat animals (beef cattle, dairy cattle, and pigs), the definition of adipose depot-specific regulation of lipid metabolism or adipogenesis, and introduces the potential value of these animals as models for metabolic research including mammary biology and the ontogeny of fatty livers.     

Catabolism and biotechnological applications of cholesterol degrading bacteria

Cholesterol is a steroid commonly found in nature with a great relevance in biology, medicine and chemistry, playing an essential role as a structural component of animal cell membranes. The ubiquity of cholesterol in the environment has made it a reference biomarker for environmental pollution analysis and a common carbon source for different microorganisms, some of them being important pathogens such as Mycobacterium tuberculosis. This work revises the accumulated biochemical and genetic knowledge on the bacterial pathways that degrade or transform this molecule, given that the characterization of cholesterol metabolism would contribute not only to understand its role in tuberculosis but also to develop new biotechnological processes that use this and other related molecules as starting or target materials.     

A role for systems epidemiology in tuberculosis research

Despite being a curable disease, tuberculosis (TB) killed more people in 2009 than during any previous year in history. Progress in TB research has been slow, and remains burdened by important gaps in our knowledge of the basic biology of Mycobacterium tuberculosis, the causative agent of TB, and its interaction with the human host. Fortunately, major systems biology initiatives have recently been launched that will help fill some of these gaps. However, to fully comprehend TB and control this disease globally, current systems biological approaches will not suffice. The influence of host and pathogen diversity, changes in human demography, and socioeconomic and environmental factors will also need to be considered. Such a multidisciplinary approach might be best described as 'systems epidemiology' in an effort to overcome the traditional boundaries between basic biology and classical epidemiology.     

New Q(ues) to keep blood vessels growing

How endothelial cells adapt their metabolism to the rising energy and biomass demands of sprouting vessels is an exciting field of research in vascular biology with numerous open questions. Two new studies published in this issue of The EMBO Journal now show the importance of glutamine in endothelial metabolism, required to sustain endothelial cell proliferation and vascular expansion. These results provide insight into how endothelial cells selectively use nutrients for energy and biomass production and illuminate new levels of regulation of the angiogenic process.     

William McElroy, the McCollum–Pratt Institute, and the Transformation of Biology at Johns Hopkins, 1945–1960

In 1948, a dynamic junior member of the Johns Hopkins Biology Department, William McElroy, became the first director of the McCollum–Pratt Institute for the Investigation of Micronutrient Elements. The Institute was founded at the university to further studies into the practicalities of animal nutrition. Ultimately, however, the Institute reflected McElroy’s vision that all biological problems, including nutrition, could be best investigated through basic biochemical and enzyme studies. The Institute quickly became a hub of biochemical research over the following decade, producing foundational work on metabolism and a respected series of symposia. In this paper, I argue that McElroy’s biochemical vantage on biology also permeated the traditionally morphological and embryological Biology Department at Hopkins. Largely due to the activity of McElroy and the Institute, the faculty, course offerings, and research underwent a radical reorientation toward biochemistry and molecular biology in the 1950s, even while maintaining a commitment to developmental biology. While the history of postwar biology is often told as the ascendancy of the “new” biology over “traditional” biology, the case of McElroy and the McCollum–Pratt Institute affords an opportunity for historical examination of biochemical and molecular science as a lens through which all branches of biology at an institution were reconceived and unified.     

A post-genomic perspective

The complete genome sequence of Mycobacterium tuberculosis, along with novel genetic tools, provides the foundation for a new era of post-genomic research. The challenge is now to translate these opportunities into an improved understanding of the complex biology of tuberculosis infection.     

果蝇免疫研究进展及其感染分枝杆菌的免疫特征

耐药性、持续感染以及与HIV病毒的共感染等诸多因素导致一度得到控制的结核病死灰复燃, 有效控制日益严峻的结核病迫切需要深入认识其致病菌——结核分枝杆菌Mycobacterium tuberculosis的基础生物学特性, 以及宿主相应的免疫控制机理。目前尚无一个动物模型能够同时回答这些关键问题, 而利用多种动物模型有望从不同角度回答上述问题, 普遍认为果蝇Drosophila 是比较理想的研究结核病天然免疫的简易模式动物之一。本文综述了果蝇免疫研究的最新进展, 包括免疫途径及其新成员与负调控子, 重点总结了用海分枝菌杆菌M. marinum、偶发分枝杆菌M. fortuitum和耻垢分枝杆菌M. smegmatis等分枝杆菌感染果蝇的新发现, 其中包括感染期间不诱导抗菌肽表达, 多个宿主因子(如CD36家族成员和ESCRT)参与了应答, 鉴定出具有杀灭分支杆菌作用的β-己糖酰胺酶, 感染期间能量代谢相关基因差异表达等。这些工作为利用果蝇模型快速筛选治疗结核病的新药物靶标和药物先导物提供了思路。     

肺外结核病微生物学诊断方法的研究和应用进展

肺外结核病指由结核分枝杆菌（Mycobacterium tuberculosis, MTB）感染所引起的发生在肺部以外器官和部位的结核病。近年来肺外结核的发病率逐渐升高,未能得到早期有效治疗的肺外结核病患者可能并发畸形、截瘫甚至死亡等严重后果。微生物学检测方法对从病原学角度诊断肺外结核病至关重要。基于此,总结了近年来肺外结核病细菌学检查方法、结核分枝杆菌的抗原检测与分子生物学检测等微生物学诊断方法的概况及应用进展,并对这些检测方法的优缺点及适用范围进行了分析、比较,以期为今后肺外结核病病原学诊断的研究提供相关信息。     

The Past and Future of Tuberculosis Research

Renewed efforts in tuberculosis (TB) research have led to important new insights into the biology and epidemiology of this devastating disease. Yet, in the face of the modern epidemics of HIV/AIDS, diabetes, and multidrug resistance—all of which contribute to susceptibility to TB—global control of the disease will remain a formidable challenge for years to come. New high-throughput genomics technologies are already contributing to studies of TB''s epidemiology, comparative genomics, evolution, and host–pathogen interaction. We argue here, however, that new multidisciplinary approaches—especially the integration of epidemiology with systems biology in what we call “systems epidemiology”—will be required to eliminate TB.     

Making metabolic decisions in Drosophila

Physiology and behavior have historically been treated as separate subjects in the study of Drosophila. The latter is mentioned mainly in the context of neurobiology, while the former has been considered to take in studies of metabolism, cell biology and anatomy, among others. Of late, the line distinguishing physiology and behavior has become thinner, and this is exceptionally apparent in recent studies of nutrient signaling and of the regulation of feeding. This review represents a brief examination of the nexus between these intersecting fields of research in Drosophila. Other recently published reviews1,2 serve as complements to this one.     

Genetic and biochemical analysis of development in Toxoplasma gondii.

Toxoplasma gondii has recently come under intense study as a model for intracellular parasitism because it has a number of properties that facilitate experimental manipulation. Attention is now being turned towards understanding the developmental biology of this complex parasite. The differentiation between the two asexual stages, the rapidly growing tachyzoites and the more slowly dividing, encysted bradyzoites, is of particular interest. Progression from the former to the latter is influenced by the host''s immune response. This paper describes current progress on a number of research fronts, all aimed at understanding the triggers that push the tachyzoite-bradyzoite equilibrium in one or other direction and the changes that occur in gene expression (and ultimately metabolism and function). Chief among the techniques used for these studies are genetics and molecular genetics. Recent progress in these areas is described.     

Genetic of modern mycobacteria of the tuberculosis complex

The review of scientific periodicals relevant to research on the mycobacteria of the tuberculosis complex with the use of modern methods of molecular biology is presented. The main mechanisms of the intraspecific variability of mycobacteria and the updated view on the tuberculosis complex mycobacteria evolution are described.     

PE_PGRS proteins are differentially expressed by Mycobacterium tuberculosis in host tissues

Characterization of PE_PGRS gene expression will help define the role of this protein family in the biology of Mycobacterium tuberculosis. In this report, quantitative real-time RT-PCR (QRT-PCR) was implemented to assess expression of three PE_PGRS genes (rv0746, rv1651c and rv1818c) under different experimental conditions. The three PE_PGRS genes showed a similar expression profile in axenic cultures, with a significant up-regulation occurring at late log and early stationary phases. rv1651c gene expression increased following intracellular growth in bone marrow-derived macrophages but not in type-II human pneumocytes, while rv0746 was induced in both in vitro systems. Following the infection of mice with M. tuberculosis, expression levels of rv1651c and rv0746 normalized to ftsZ and 16S rRNA were highest in the spleen tissue during the chronic stages of murine tuberculosis, with a >20- and >30-fold up-regulation, respectively. Levels of expression remained lower in the lung over the same time period. Expression of the rv1818c gene did not change significantly under different experimental conditions tested. The results of this study indicate that M. tuberculosis can differentially regulate expression of PE_PGRS genes and that genes such as rv0746 and rv1651c are significantly induced while M. tuberculosis persists in host cells and tissues.     

Genomics of brown algae: current advances and future prospects

The analysis of the complete genome sequence of the filamentous brown alga Ectocarpus provided many new insights into brown algal biology and has improved our understanding of how this organism has adapted to its seashore environment. Since the publication of the genome sequence in 2010, numerous studies have continued the analysis of the constituent genes or have combined genome data with experimental work, allowing progress in several key areas, including metabolism and reproductive biology. Ectocarpus will continue to be exploited as a model organism in future years, but genomic approaches should also be extended to additional brown algal species in order to fully exploit the diversity of this phylogenetic group and to facilitate the application of new knowledge to economically important seaweeds such as kelps.     

A comprehensive view of polyamine and histamine metabolism to the light of new technologies

Polyamines and histamine are biogenic amines with multiple biological roles. In spite of the evidence for the involvement of both polyamines and histamine metabolism impairment in several highly prevalent pathological conditions, multiple questions concerning the molecular processes behind these effects remain to be elucidated. More comprehensive and systemic studies integrating molecular biology, biophysical and bioinformatics tools could contribute to accelerate the advances in this research area. This review is designed to underscore the main questions to be answered in polyamine and histamine research and how these new systemic approaches could help to find these answers.     

人结核分枝杆菌特异性核酸探针制备及结核病PCR检测技术的初步临床应用

采用人结核分枝杆菌(Mycobacterium tuberculosis TB)染色体DNA为模板,选择位于插入片段IS6110中884～865和568～588碱基对处的两个片段为引物,扩增出317bp的特异性片段．将其克隆进pUCl9载体。酶切图谱分析和DNA序列测定证实为目的片段。该片段经DIG标记,分别与11种分枝杆菌DNA进行Southern杂交,结果证明只与人型复合分枝杆菌发生杂交反应。利用该对引物建立的PcR检测拄术对74份结核病痰液标本进行检测,并与临床细菌快速培养结果相比较,发现48份临床阳性均为PcR阳性,在26份临床阴性标本中亦发现11份PCR检测阳性。将标本PCR产物与克隆探针进行杂交,显示两者结果完全一致。说明PCR检测体系结果可靠,其灵敏度明显高于目前临床所采用的方法,可作为一种常规技术用于结核病的临床检测。     

EXPERIMENTAL PLANT REPRODUCTIVE BIOLOGY AND REPRODUCTIVE CELL MANIPULATION IN HIGHER PLANTS: NOW AND THE FUTURE

Experimental plant reproductive biology has recently emerged as a new form of experimental embryology characterized by the direct experimental isolation and manipulation of reproductive cells and protoplasts. This work is fostered by current multidisciplinary trends in the sciences and serves to deepen our knowledge about the control of reproductive processes by providing novel in vitro material. The techniques of experimental plant reproductive biology also show great potential in providing new means for biotechnology, leading to significant refinements in plant breeding in higher plants that may eventually permit direct reproductive cell engineering. Recent achievements by our research group in experimental manipulation and biological studies of pollen protoplasts, generative cells, sperm cells, and embryo sacs are reviewed, and some ideas about future developments in this new area are presented.     

Life history evolution and comparative developmental biology of echinoderms

Evolutionary biologists studying life history variation have used echinoderms in experimental, laboratory, and field studies of life history evolution. This focus on echinoderms grew originally from the tradition of comparative embryology, in which echinoderms were central. The tools for obtaining and manipulating echinoderm gametes and larvae were taken directly from comparative embryological research. In addition, the comparative embryologists employed a diverse array of echinoderms, not a few model species, and this diversity has led to a broad understanding of the development, function, and evolution of echinoderm larvae. As a result, this branch of life history evolution has deep roots in comparative developmental biology of echinoderms. Here two main aspects of this relationship are reviewed. The first is a broad range of studies of fertilization biology, dispersal, population genetics, functional morphology, and asexual reproduction in which developmental biologists might take a keen interest because of the historical origins of this research in echinoderm comparative embryology. The second is a similarly broad variety of topics in life history research in which evolutionary biologists require techniques or data from developmental biology in order to make progress on understanding patterns of life history variation among echinoderm species and higher taxa. Both sets of topics provide opportunities for interaction and collaboration.     

New surveyor tools for charting microbial metabolic maps

The computational reconstruction and analysis of cellular models of microbial metabolism is one of the great success stories of systems biology. The extent and quality of metabolic network reconstructions is, however, limited by the current state of biochemical knowledge. Can experimental high-throughput data be used to improve and expand network reconstructions to include unexplored areas of metabolism? Recent advances in experimental technology and analytical methods bring this aim an important step closer to realization. Data integration will play a particularly important part in exploiting the new experimental opportunities.