生物质能源四十年

为应对1973年全球石油危机而发展起来的现代生物质能源已渐趋成熟,在对化石能源的替代中发挥着越来越突出的作用。回顾了生物质能源40年的发展历程,对液体生物燃料、生物天然气和固体生物燃料与发电作了专门叙述。就生物质能源与中国,以及中国发展生物质能源方略发表了自己的见解。     

浅谈发育生物学实验教学改革及创新能力培养

实验教学是培养具有创新精神和实践能力的应用型人才的重要途径.发育生物学是一门新兴学科,其实验教学存在教学内容参差不齐和教学环节薄弱等诸多问题,实行教学改革迫在眉睫.通过对发育生物学实验教学改革的实践经验进行总结,以期对同类高校该课程实验教学有所借鉴和参考,共同完善发育生物学实验教学环节.     

Ecological developmental biology: developmental biology meets the real world

The production of phenotype is regulated by differential gene expression. However, the regulators of gene expression need not all reside within the embryo. Environmental factors, such as temperature, photoperiod, diet, population density, or the presence of predators, can produce specific phenotypes, presumably by altering gene-expression patterns. The field of ecological developmental biology seeks to look at development in the real world of predators, competitors, and changing seasons. Ecological concerns had played a major role in the formation of experimental embryology, and they are returning as the need for knowledge about the effects of environmental change on embryos and larvae becomes crucial. This essay reviews some of the areas of ecological developmental biology, concentrating on new studies of amphibia and Homo.     

Ediacaran developmental biology

Rocks of the Ediacaran System (635–541 Ma) preserve fossil evidence of some of the earliest complex macroscopic organisms, many of which have been interpreted as animals. However, the unusual morphologies of some of these organisms have made it difficult to resolve their biological relationships to modern metazoan groups. Alternative competing phylogenetic interpretations have been proposed for Ediacaran taxa, including algae, fungi, lichens, rhizoid protists, and even an extinct higher‐order group (Vendobionta). If a metazoan affinity can be demonstrated for these organisms, as advocated by many researchers, they could prove informative in debates concerning the evolution of the metazoan body axis, the making and breaking of axial symmetries, and the appearance of a metameric body plan. Attempts to decipher members of the enigmatic Ediacaran macrobiota have largely involved study of morphology: comparative analysis of their developmental phases has received little attention. Here we present what is known of ontogeny across the three iconic Ediacaran taxa Charnia masoni, Dickinsonia costata and Pteridinium simplex, together with new ontogenetic data and insights. We use these data and interpretations to re‐evaluate the phylogenetic position of the broader Ediacaran morphogroups to which these taxa are considered to belong (rangeomorphs, dickinsoniomorphs and erniettomorphs). We conclude, based on the available evidence, that the affinities of the rangeomorphs and the dickinsoniomorphs lie within Metazoa.     

Principles of developmental biology

The field of developmental biology has a history that spans the last 500 years. Within the last 10 years, our understanding of developmental mechanisms has grown exponentially by employing modern techniques of genetics and molecular biology, frequently combined with experimental embryology and the use of molecular markers, rather than solely morphology, to identify critical populations of cells and their state of differentiation. Three main principles have emerged. First, mechanisms of development are highly conserved, both among developing rudiments of a variety of organ systems and among diverse organisms. This conservation occurs both at the level of tissue and cellular mechanisms, and at the molecular level. Second, the development of organ rudiments is influenced by surrounding tissues through interactions called inductive interactions. Such interactions are mediated by highly conserved growth factors and signaling systems. Third, development is a life-long process and can be reawakened in events such as wound healing and regeneration, and in certain diseases. Advances in understanding normal development provide hope that diseases in which development runs amuck, such as cancer, may soon be preventable and fully treatable. Supported by NS 18112 and DC 04185 from the NIH.     

Model systems in developmental biology

The practical criteria by which developmental biologists choose their model systems have evolutionary correlates. The result is a sample that is not merely small, but biased in particular ways, for example towards species with rapid, highly canalized development. These biases influence both data collection and interpretation, and our views of how development works and which aspects of it are important.     

Fluorescence techniques in developmental biology

Advanced fluorescence techniques, commonly known as the F-techniques, measure the kinetics and the interactions of biomolecules with high sensitivity and spatiotemporal resolution. Applications of the F-techniques, which were initially limited to cells, were further extended to study in vivo protein organization and dynamics in whole organisms. The integration of F-techniques with multi-photon microscopy and light-sheet microscopy widened their applications in the field of developmental biology. It became possible to penetrate the thick tissues of living organisms and obtain good signal-to-noise ratio with reduced photo-induced toxicity. In this review, we discuss the principle and the applications of the three most commonly used F-techniques in developmental biology: Fluorescence Recovery After Photo-bleaching (FRAP), Förster Resonance Energy Transfer (FRET), and Fluorescence Correlation and Cross-Correlation Spectroscopy (FCS and FCCS).     

Comparative methods in developmental biology

The need for a phylogenetic framework is becoming appreciated in many areas of biology. Such a framework has found limited use in developmental studies. Our current research program is therefore directed to applying comparative and phylogenetic methods to developmental data. In this paper, we examine the concepts underlying this work, discuss potential difficulties, and identify some solutions. While developmental biologists frequently make cross-species comparisons, they usually adopt a phenetic approach, whereby degrees of overall similarity in development are sought. Little emphasis is placed on reconstructing the evolutionary divergence in developmental characters. Indeed, developmental biologists have historically concentrated on apparently ‘conserved’ or ‘universal’ developmental mechanisms. Thus, there has been little need for phylogenetic methodologies which analyse specialised features shared only within a subset of species (i.e., synapomorphies). We discuss the potential value of such methodologies, and argue that difficulties in adapting them to developmental studies fall into three interlinked areas: One concerns the nature and definition of developmental characters. Another is the difficulty of identifying equivalent developmental stages in different species. Finally the phylogenetic non-independence of developmental characters presents real problems under some protocols. These problems are not resolved. However, it is clear that the application of phylogenetic methodology to developmental data is both necessary and fundamental to research into the relationship between evolution and development.     

New developments in developmental biology

A report on the 15th International Society of Developmental Biologists Congress, Sydney, Australia, 3-7 September 2005.     

How developmental is evolutionary developmental biology?

Evolutionary developmental biology (evo-devo) offers both an account of developmental processes and also new integrative frameworks for analyzing interactions between development and evolution. Biologists and philosophers are keen on evo-devo in part because it appears to offer a comfort zone between, on the one hand, what some take to be the relative inability of mainstream evolutionary biology to integrate a developmental perspective; and, on the other hand, what some take to be more intractable syntheses of development and evolution. In this article, I outline core concerns of evo-devo, distinguish theoretical and practical variants, and counter Sterelny's recent argument that evo-devo's attention to development, while important, offers no significant challenge to evolutionary theory as we know it. This revised version was published online in July 2006 with corrections to the Cover Date.     

Six decades of Neurospora ascus biology at Stanford

Ascus is the largest cell in the entire life cycle of Neurospora; it is where the transient diploid nucleus undergoes meiosis and a postmeiotic mitosis. The eight haploid nuclei are then sequestered into eight linearly ordered ascospores. Dodge's pioneering work on Neurospora and its simple nutritional requirements inspired Beadle and Tatum of Stanford University to use N. crassa for their landmark demonstration that individual genes specify enzymes. McClintock visited Stanford in 1944, and showed that meiosis and chromosome behaviour in Neurospora are similar to those of higher eukaryotes. Most of the subsequent Neurospora ascus biology work was carried out in David Perkins' laboratory at Stanford from 1960–2007. Since 1974, I have extensively used an iron-haematoxylin staining procedure, the DNA-specific fluorochrome acriflavine, and GFP-tagged genes for visualizing meiotic chromosome behaviour and gene silencing during ascus and ascospore development. Our recent discovery of meiotic silencing, and the availability of genome sequence and GFP-tagged genes will no doubt pave the way for molecular analysis of complex processes during ascus development.