Understanding Quantitative Genetics in the Systems Biology Era

Biology is now entering the new era of systems biology and exerting a growing influence on the future development of various disciplines within life sciences. In early classical and molecular periods of Biology, the theoretical frames of classical and molecular quantitative genetics have been systematically established, respectively. With the new advent of systems biology, there is occurring a paradigm shift in the field of quantitative genetics. Where and how the quantitative genetics would develop after having undergone its classical and molecular periods? This is a difficult question to answer exactly. In this perspective article, the major effort was made to discuss the possible development of quantitative genetics in the systems biology era, and for which there is a high potentiality to develop towards "systems quantitative genetics". In our opinion, the systems quantitative genetics can be defined as a new discipline to address the generalized genetic laws of bioalleles controlling the heritable phenotypes of complex traits following a new dynamic network model. Other issues from quantitative genetic perspective relating to the genetical genomics, the updates of network model, and the future research prospects were also discussed.     

Contributions and promise of human behavioral genetics

Human behavioral genetics has contributed greatly to our understanding of human behavioral development. Twin, family, and adoption studies have shown that genetic effects are ubiquitous and that both genes and environments contribute to individual differences in behavior. The unique ability of behavioral genetic methods to separate genetic from environmental effects has also led to important discoveries about how the environment works in development and to the elucidation of the complex ways environments and genes interact across the life span. Although quantitative methods have been the mainstay of the field of human behavioral genetics since Galton's time, the Human Genome Project and advances in molecular genetics are providing new tools and promise as we enter the 21st century. Thus the future of human behavioral genetics lies in the cross-disciplinary exchanges and collaborations that will increasingly occur in the years to come among quantitative and molecular scientists who work with both animal and human systems. This research may someday culminate in an understanding of the biological basis of behavior that spans from how the brain develops and functions to a grasp of how genes influence thought at the molecular level.     

模式生物衣藻及其研究进展

单细胞衣藻（Chlamydomonas）由于其生活周期简单,培养方法简便,易于分离得到系列的突变体,并已建立了分子遗传学研究技术与遗传分析系统,成为植物光合作用、鞭毛组装与功能、细胞周期及节律、细胞信号传导与光感受、细胞识别等重要生物学过程研究的模式生物体。本文对模式生物衣藻及其相关生物学途径的研究进展作一综述。 Abstract:The unicellular alga Chlamydomonas offers a simple life cycle,easy culture and isolation of series of mutants,established the techniques and tool kit for molecular genetics and genetics analysis.It is now becoming the model organism for studies on photosynthesis in plant,flagellar assembly and function,cell cycle and circadian rhythms,signal transduction,light perception and cell recognition.It is summarized the progress of study on Chlamydomonas as a model organism in this paper.     

Microsatellites or the eukaryotic genome: life cycle concept and neutrality issues

Microsatellite markers have a great discriminating power. Widely exploited in many disciplines such as forensic science, medical genetics, conservation biology and molecular ecology, they are also used in human population genetics to illuminate our origins. However, strikingly, their fundamental evolutionary mechanisms remain obscure, because of the difficulty of disentangling the complex and numerous factors involved. After a brief summary of their basic characteristics, the concept of life cycle size-dependant is explored. The major mechanisms known to explain the four different phases of their life (conception, birth, growing and senescence/renaissance) are discussed. Emerging questions about their neutrality are also investigated, pointing out a real need to improve our understanding of their mutational dynamics.     

Integrating evolutionary and molecular genetics of aging

Aging or senescence is an age-dependent decline in physiological function, demographically manifest as decreased survival and fecundity with increasing age. Since aging is disadvantageous it should not evolve by natural selection. So why do organisms age and die? In the 1940s and 1950s evolutionary geneticists resolved this paradox by positing that aging evolves because selection is inefficient at maintaining function late in life. By the 1980s and 1990s this evolutionary theory of aging had received firm empirical support, but little was known about the mechanisms of aging. Around the same time biologists began to apply the tools of molecular genetics to aging and successfully identified mutations that affect longevity. Today, the molecular genetics of aging is a burgeoning field, but progress in evolutionary genetics of aging has largely stalled. Here we argue that some of the most exciting and unresolved questions about aging require an integration of molecular and evolutionary approaches. Is aging a universal process? Why do species age at different rates? Are the mechanisms of aging conserved or lineage-specific? Are longevity genes identified in the laboratory under selection in natural populations? What is the genetic basis of plasticity in aging in response to environmental cues and is this plasticity adaptive? What are the mechanisms underlying trade-offs between early fitness traits and life span? To answer these questions evolutionary biologists must adopt the tools of molecular biology, while molecular biologists must put their experiments into an evolutionary framework. The time is ripe for a synthesis of molecular biogerontology and the evolutionary biology of aging.     

植物分子群体遗传学研究动态

分子群体遗传学是当代进化生物学研究的支柱学科, 也是遗传育种和关于遗传关联作图和连锁分析的基础理论学科。分子群体遗传学是在经典群体遗传的基础上发展起来的, 它利用大分子主要是DNA序列的变异式样来研究群体的遗传结构及引起群体遗传变化的因素与群体遗传结构的关系, 从而使得遗传学家能够从数量上精确地推知群体的进化演变, 不仅克服了经典的群体遗传学通常只能研究群体遗传结构短期变化的局限性, 而且可检验以往关于长期进化或遗传系统稳定性推论的可靠程度。同时, 对群体中分子序列变异式样的研究也使人们开始重新审视达尔文的以“自然选择”为核心的进化学说。到目前为止, 分子群体遗传学已经取得长足的发展, 阐明了许多重要的科学问题, 如一些重要农作物的DNA多态性式样、连锁不平衡水平及其影响因素、种群的变迁历史、基因进化的遗传学动力等, 更为重要的是, 在分子群体遗传学基础上建立起来的新兴的学科如分子系统地理学等也得到了迅速的发展。文中综述了植物分子群体遗传研究的内容及最新成果。     

Extending and expanding the Darwinian synthesis: the role of complex systems dynamics

Darwinism is defined here as an evolving research tradition based upon the concepts of natural selection acting upon heritable variation articulated via background assumptions about systems dynamics. Darwin's theory of evolution was developed within a context of the background assumptions of Newtonian systems dynamics. The Modern Evolutionary Synthesis, or neo-Darwinism, successfully joined Darwinian selection and Mendelian genetics by developing population genetics informed by background assumptions of Boltzmannian systems dynamics. Currently the Darwinian Research Tradition is changing as it incorporates new information and ideas from molecular biology, paleontology, developmental biology, and systems ecology. This putative expanded and extended synthesis is most perspicuously deployed using background assumptions from complex systems dynamics. Such attempts seek to not only broaden the range of phenomena encompassed by the Darwinian Research Tradition, such as neutral molecular evolution, punctuated equilibrium, as well as developmental biology, and systems ecology more generally, but to also address issues of the emergence of evolutionary novelties as well as of life itself.     

Cerebral small vessel disease: genetic risk assessment for prevention and treatment

Cerebrovascular disease is a major burden to individuals and their communities worldwide. Stroke is one of the leading causes of death and disability, and the prevention and treatment of stroke can be improved with a better understanding of its causation. Cerebral small vessel disease (SVD) is a subset of cerebrovascular disease, and has an equally large impact on an individual's quality of life. Although many risk factors are involved, we propose that genetics has a significant role in the pathogenesis of SVD through a complex interplay of environmental and multigenetic factors. Advances in molecular technology have enabled the human genome to be investigated both at a population and, more recently, an individual level. A better understanding of the molecular basis of SVD will enable the development of therapies to help in its prevention and treatment. This review assesses the molecular genetics underlying cerebral SVD.     

Molecular biology and Pauling's immunochemistry: a neglected dimension

This paper argues that there is a substantial overlap between the history of immunology and the history of molecular biology, an overlap manifested in the researches on antibodies during the 1930s and 1940s. This common ground is a product of intellectual developments, as well as institutional trends. Viewed from an intellectual vantage point of the 1930s and 1940s, molecular biology was essentially the study of the biological specificities of the so-called 'giant protein molecules'. Within the conceptual framework of early molecular biology, which was rooted in the protein view of life, the concepts of protein template, autocatalysis, and heterocatalysis were central in explaining the protein syntheses of genes, viruses, enzymes, hormones, and antibodies. Immunochemistry and serological genetics were at the heart of that research agenda. This paper also shows that the immunochemistry program of Linus Pauling, which focused on molecular mechanisms of antibody structure and function, and the projects in serological genetics at Caltech's biology division were supported by the Rockefeller Foundation under the aegis of its molecular biology program. Based on the close examination of intellectual and institutional factors, the histories of molecular biology and immunology in the pre-DNA era are seen as closely linked.     

Nikolaĭ Vladimirovich Timofeev-Resovskiĭ (1900-1981). (Essay on his life and works)

The article contains a brief review of the basic works (1925-1981) written by Nikolay V. Timofeeff-Ressovsky--one of the famous geneticist of the elapsing century, the founder of radiobiology and radiation genetics, biocenology and radioecology, a prominent evolutionary biologist. In genetics, his name is associated with the development of fundamental problems of population genetics, phenogenetics, gene interaction and investigations of the role of environmental and genetic factors in expression of different characters. Timofeeff-Ressovsky classical works on mutagenesis process and especially, radiation mutagenesis, promoted penetration of methods and approaches applied in molecular physics and chemistry, into genetic analysis, and accelerated forming of the modern molecular genetics. A special place in the development of population genetics is occupied by the hypothesis of microevolutionary process developed by Nikolay V. Timofeeff-Ressovsky along with other famous biologists in the end of the 30-ies. This hypothesis connected Darwin's evolutionary theory with rapidly developing concepts of genetics. In the last years of his life, Timofeeff-Ressovsky was especially interested in a global problem which was called by him "The Biosphere and Humanity". Here was especially strikingly shown the broadness of his approach to the analysis of the biosphere phenomena in the best traditions of the Russian natural science. In the course of time, the wealth of Nikolay V. Timofeeff-Ressovsky's scientific heritage not only remains valuable, but also takes on more profundity and value.     

医学病例在高校普通遗传学教学中的运用

遗传学是生命科学、医学、农学等相关领域的核心课程。作为21世纪生命科学中发展最为迅速的学科之一,教学内容复杂、更新快,遗传学知识对人一生的影响也日益增强,特别是与医学相关的遗传学知识更是受到大众关注。为使学生更容易理解深奥的遗传学知识,使教学内容更贴近生活,在教学过程中引入医学病例,将相应的医学病例同遗传学理论知识结合并作出适当的延伸,将有利于提高学生的遗传学知识综合分析能力,同时提高学生的学习积极性和实用技能。本文根据现代遗传学教学体系,引入相应的医学病例,强调培养学生综合遗传分析能力,为综合性大学、师范院校的普通遗传学教学提供参考。     

Advancing ecological understandings through technological transformations in noninvasive genetics

Noninvasive genetic approaches continue to improve studies in molecular ecology, conservation genetics and related disciplines such as forensics and epidemiology. Noninvasive sampling allows genetic studies without disturbing or even seeing the target individuals. Although noninvasive genetic sampling has been used for wildlife studies since the 1990s, technological advances continue to make noninvasive approaches among the most used and rapidly advancing areas in genetics. Here, we review recent advances in noninvasive genetics and how they allow us to address important research and management questions thanks to improved techniques for DNA extraction, preservation, amplification and data analysis. We show that many advances come from the fields of forensics, human health and domestic animal health science, and suggest that molecular ecologists explore literature from these fields. Finally, we discuss how the combination of advances in each step of a noninvasive genetics study, along with fruitful areas for future research, will continually increase the power and role of noninvasive genetics in molecular ecology and conservation genetics.     

嗜酸菌研究进展

极端环境微生物是当今生命科学领域的研究热点。嗜酸菌是极端环境微生物的重要类群,在人们生活生产中发挥着巨大的作用。介绍了嗜酸菌的主要类群及特征,阐述了它们在自然界的主要行为、适应酸和重金属的生理机制以及分子遗传学研究进展,最后介绍了嗜酸菌在实际生产中的主要应用。     

Mapping development or how molecular is molecular biology?

The transformation of embryology to developmental biology has been linked to the introduction of experimental approaches from molecular genetics to the study of development. This paper pursues this theme by analyzing the tools molecular biologists, moving from phage and bacterial genetics to the study of development in higher organisms, brought to their new field of investigations. The paper focuses on Sydney Brenner's move from molecular genetics to developmental biology. His attempt to turn the nematode worm Caenorhabditis elegans into a new tool for the study of development included a vast and ever expanding mapping program. Worm workers themselves did not distinguish sharply between mapping on the cellular, chromosomal or molecular level. Mapping, the paper argues, or more generally 'analytical/comparative' next to 'experimentalist' approaches (Pickstone) were not only part and parcel of Brenner's strategy to 'molecularize' the study of development, but also played a crucial role in 'classical' molecular biology.     

Molecular insights into the causes of male infertility

Infertility is a reproductive health problem that affects many couples in the human population. About 13–18% of couple suffers from it and approximately one-half of all cases can be traced to either partner. Regardless of whether it is primary or secondary infertility, affected couples suffer from enormous emotional and psychological trauma and it can constitute a major life crisis in the social context. Many cases of idiopathic infertility have a genetic or molecular basis. The knowledge of the molecular genetics of male infertility is developing rapidly, new “spermatogenic genes” are being discovered and molecular diagnostic approaches (DNA chips) established. This will immensely help diagnostic and therapeutic approaches to alleviate human infertility. The present review provides an overview of the causes of human infertility, particularly the molecular basis of male infertility and its implications for clinical practice.     

Phylogeny and evolutionary biology

The phylogenetic system of Hennig, which was designed for classification of synchronous organisms, has only been adapted secondarily to total reconstruction of phylogeny. All fields of fundamental biology are related to the development of evolutionary theory. A better understanding of the origin of life requires new concepts of the historical geology of prebiological environment and new concepts of molecular genetics and biochemistry concerning ribonucleic acids as the initial units for the origin of life.     

CRISPR/Cas工具——分子遗传研究的新刃

遗传与变异体现着生命之美和生命之奥妙,前人在不断探求的过程中逐渐形成了严谨的体系和科学的方法——遗传学。在遗传学的研究中基因编辑工具的作用是不可或缺的,近年来发现的CRISPR/Cas系统作为基因编辑工具箱中的新刃,以其特异性强、靶向性好、适用性广的特点迅速成为广大科研工作者研究和开发的热点。并且,在探索生命暗物质的过程中,会有更多的新的CRISPR/Cas系统被发现并应用在遗传研究等领域。为此,本文综述目前CRISPR/Cas系统的最新研究进展,力图从其系统多样性、分子工作机制及遗传研究应用等方面,为广大科研工作者提供一个系统了解CRISPR/Cas系统及其研究现状的窗口,以期为该领域的研究与应用提供一些有益的参考。     

The art and design of genetic screens: Arabidopsis thaliana

Molecular genetic studies rely on well-characterized organisms that can be easily manipulated. Arabidopsis thaliana--the model system of choice for plant biologists--allows efficient analysis of plant function, combining classical genetics with molecular biology. Although the complete sequence of the Arabidopsis genome allows the rapid discovery of the molecular basis of a characterized mutant, functional characterization of the Arabidopsis genome depends on well-designed forward genetic screens, which remain a powerful strategy to identify genes that are involved in many aspects of the plant life cycle.