Evolutionary genomics: new genes for new jobs

Whole genome sequence analyses have confirmed that gene duplication and divergence play major roles in genome evolution. But the details of how young, functionally redundant gene duplicates escape mutational degradation have remained elusive. Several recent studies show that new genes survive because they evolve new, and sometimes essential, functions.     

Regulation of cAMP and cGMP signaling: new phosphodiesterases and new functions

The past eighteen months have provided much progress in the cyclic nucleotide phosphodiesterase (PDE) field. Six new phosphodiesterase genes have been discovered and characterized. In addition, several new highly specific PDE inhibitors have been developed and approved for clinical use. Finally, new strategies have been employed to determine PDE function in model systems including the use of antisense oligonucleotide and disruption techniques.     

Malaria drug-sensitivity testing: new assays,new perspectives

Over the past five decades, the drug resistance of Plasmodium falciparum has become an issue of utmost concern. At the same time, in vitro assays for assessing antimalarial drug sensitivity have become indispensable tools for the surveillance of drug resistance and the planning of therapeutic guidelines. Several new in vitro assays have been introduced, designed to be easier to handle than previous tests and allow a faster identification of drug-resistant parasites, as well as for simple evaluation of new drugs. This review examines the various new approaches to the in vitro assessment of malaria drug sensitivity and their limitations.     

ER-mediated phagocytosis: a new membrane for new functions

Genomics and other high-throughput approaches, such as proteomics, are changing the way we study complex biological systems. In the past few years, these approaches have contributed markedly to improving our understanding of phagocytosis. Indeed, the ability to study biological systems by monitoring hundreds of proteins provides a level of resolution that is not attainable by the usual 'one protein at a time' approach. In this article, I discuss how proteomic approaches have revealed surprising findings that enable us to revisit established concepts, such as the origin of the phagosome membrane, and to propose new models of cell organization and the link between innate and adaptive immunity.     

Plant cell biology in the new millennium: new tools and new insights

The highly regulated structural components of the plant cell form the basis of its function. It is becoming increasingly recognized that cellular components are ordered into regulatory units ranging from the multienzyme complexes that allow metabolic channeling during primary metabolism to the "transducon" complexes of signal transduction elements that allow for the highly efficient transfer of information within the cell. Against this structural background the highly dynamic processes regulating cell function are played out. Recent technological advances in three areas have driven our understanding of the complexities of the structural and functional dynamics of the plant cell. First, microscope and digital camera technology has seen not only improvements in the resolution of the optics and sensitivity of detectors, but also the development of novel microscopy applications such as confocal and multiphoton microscopy. These technologies are allowing cell biologists to image the dynamics of living cells with unparalleled three-dimensional resolution. The second advance has been in the availability of increasingly powerful and affordable computers. The computer control/analysis required for many of the new microscopy techniques was simply unavailable until recently. Third, there have been dramatic advances in the available probes to use with these new microscopy approaches. Thus the plant cell biologist now has available a vast array of fluorescent probes that will report cell parameters as diverse as the pH of the cytosol, the oxygen level in a tissue, or the dynamics of the cytoskeleton. The combination of these new approaches has led to an increasingly detailed picture of how plant cells regulate their activities.     

The new oral anticoagulants

In patients with nonvalvular atrial fibrillation oral anticoagulation with the vitamin K antagonists acenocoumarol, phenprocoumon and warfarin reduces the risk of stroke by more than 60%, whereas single or double antiplatelet therapy is much less effective and sometimes associated with a similar bleeding risk as vitamin K antagonists. Besides bleeding, INR monitoring and high interindividual variability remain the largest drawbacks of vitamin K antagonists. In the last decade oral agents have been developed that directly block the activity of thrombin (factor IIa), as well as drugs that directly inhibit activated factor X (Xa), which is the first protein in the final common pathway to the activation of thrombin. These agents have huge advantages in that they do not need monitoring and have a fast onset and offset of action. This survey addresses the role of classical and modern anticoagulation in stroke prevention in atrial fibrillation. (Neth Heart J 2010;18:314-8.)     

A new beginning with new ends: linearisation of circular chromosomes during bacterial evolution

Bacterial circular chromosomes have sporadically become linearised during prokaryote evolution. Unrelated bacteria, including the spirochete Borrelia burgdorferi and the actinomycete Streptomyces, have linear chromosomes. Linear chromosomes may have been formed through integration of linear plasmids. Linear chromosomes use linear plasmid strategies to resolve the 'end-of-replication problem', but they have generally retained from their circular ancestors a central origin of replication. Streptomyces linear chromosomes are very unstable and at high frequency undergo amplifications and large deletions, often removing the telomeres. At least in Streptomyces, chromosome linearity is reversible: circular chromosomes arise spontaneously as products of genetic instability or can be generated artificially by targeted recombination. Streptomyces circularised chromosomes are very unstable as well, indicating that genetic instability is not confined to the linearised chromosomes. Bacterial linear chromosomes may contain telomere-linked regions of enhanced genomic plasticity, which undergo more frequent genetic exchanges and rearrangements and allow differential evolution of genes, depending on their chromosomal location.     

中国植物新分类群、新名称2020年度报告

2020年中国共发表高等植物新分类群359个, 其中新属21个、新种312个、新亚种6个、新变种14个、新变型6个; 发表新组合(等级) 217个, 新名称11个; 发表国家级新记录48个; 将85个名称处理为65个名称的异名; 对14个名称进行了应用订正; 新指定后选(新)模式物种147个; 还新发现多年未曾发现的物种2个, 排除物种分布3个。新发表的物种中, 苔类植物门有3个、藓类植物门3个、蕨类植物门6个、裸子植物门1个新杂交种、被子植物门299个。这些新物种中, 有86个发表的同时提供了详细的分子证据, 78个在发表时就依据IUCN标准被评估处于受威胁的状态。云南、西藏、广西和四川等西南4省区发表新物种最多, 占全国新物种发表总数的2/3; 新物种发现密度最高的省级行政单位是云南、海南、台湾、广西和浙江等省区; 墨脱县是新物种发现数量最多的县级行政单位。2020年中国高等植物净新增294个分类群, 占全国总数的0.79%, 313个高等植物名称发生变动, 占全国总数的0.84%。     

Protein architecture: new superfamilies

Protein families whose members have evolved beyond any statistically significant similarities in sequence are sometimes called superfamilies. Structural and functional characteristics are conserved within such families and can be revealed by an analysis of protein architecture. We describe ten superfamilies that have resulted from recently determined structures; four of these are described here for the first time.     

Evolving new genetic codes

Although the genetic code is almost universal, natural variations exist that have caused evolutionary biologists to speculate about codon evolution. There are two predominant hypotheses that specify either a gradual (ambiguous intermediate) or stochastic (codon capture) change in the code. These hypotheses are similar to two biotechnology techniques that have been used to engineer the genetic code: a 'top down' approach, in which the whole organism is evolved for the ability to incorporate unnatural amino acids, and a 'bottom up' approach, in which aminoacyl-tRNA synthetases and their cognate tRNAs are engineered. The biotechnology experiments provide insights into natural codon evolution, and a combination of these approaches should enable the evolution of organisms that can incorporate unnatural amino acids throughout their proteomes.     

Conserved 'hypothetical' proteins: new hints and new puzzles

Conserved hypothetical proteins, i.e. conserved proteins whose functions are still unknown, pose a challenge not just to functional genomics but also to general biology. For many conserved proteins, computational analysis provides only a general prediction of biochemical function; their exact biological functions have to be established through direct experimentation. In the few cases when this has been accomplished, the results were remarkable, revealing the deoxyxylulose pathway and a new essential enzyme, the ITP pyrophosphatase. Comparative genome analysis is also instrumental in illuminating unsolved problems in biology, e.g. the mechanism of FtsZ-independent cell division in Chlamydia, Ureaplasma and Aeropyrum or the role of uncharacterized conserved domains in signal transduction.     

The promise of new ideas and new technology for improving teaching and learning

There have been enormous advances in our understanding of human learning in the past three decades. There have also been important advances in our understanding of the nature of knowledge and new knowledge creation. These advances, when combined with the explosive development of the Internet and other technologies, permit advances in educational practices at least as important as the invention of the printing press in 1460. We have built on the cognitive learning theory of David Ausubel and various sources of new ideas on epistemology. Our research program has focused on understanding meaningful learning and on developing better methods to achieve such learning and to assess progress in meaningful learning. The concept map tool developed in our program has proved to be highly effective both in promoting meaningful learning and in assessing learning outcomes. Concept mapping strategies are also proving powerful for eliciting, capturing, and archiving knowledge of experts and organizations. New technology for creating concept maps developed at the University of West Florida permits easier and better concept map construction, thus facilitating learning, knowledge capture, and local or distance creation and sharing of structured knowledge, especially when utilized with the Internet. A huge gap exists between what we now know to improve learning and use of knowledge and the practices currently in place in most schools and corporations. There are promising projects in progress that may help to achieve accelerated advances. These include projects in schools at all educational levels, including projects in Colombia, Costa Rica, Italy, Spain, and the United States, and collaborative projects with corporate organizations and distance learning projects. Results to date have been encouraging and suggest that we may be moving from the lag phase of educational innovation to a phase of exponential growth.     

What's new in cardiovascular surgery

Advances in the treatment of congenital cardiovascular lesions have led to a renewed interest in the treatment of acquired heart disease. Although this field could best be served by the perfection of the extracorporal heart, such devices are as yet not ready for human application. Meanwhile, various approaches through the ventricles and left atrium have been developed to treat valvular stenosis. Refinements in diagnostic tests and in methods of physiological investigation are of great aid in the proper evaluation of patients.