Genetics of growth predict patterns of brain-size evolution

Experimental evidence is presented supporting a developmental model that explains the genetic basis for brain and body size associations. Evolutionary change in body size causes correlated change in brain size because some genes affect both traits. The commonly observed correlation between brain and body size results from genetic variation in growth determinants affecting both traits simultaneously during fetal and early postnatal growth. Later growth reduces brain-body correlation because of changes in the underlying causal components of growth in each trait. Brain-body size evolution shows a different pattern at higher taxonomic levels from that seen within and between closely related species because body-size evolution among higher taxa occurs primarily by change in early portions of growth, which share more genetic growth determinants with brain size.     

Teosinte glume architecture 1: A Genetic Locus Controlling a Key Step in Maize Evolution

Teosinte, the probable progenitor of maize, has kernels that are encased in hardened fruitcases, which interfere with the use of the kernels as food. Although the components of the fruitcase are present in maize, their development is disrupted so that the kernels are not encased as in teosinte but exposed on the ear. The change from encased to exposed kernels represents a key step in maize evolution. The locus that largely controls this morphological difference between maize and teosinte, teosinte glume architecture 1, is described and genetically mapped.     

试析《巴黎协定》中的国家自主贡献模式及中国的承诺

《巴黎协定》中的“国家自主贡献”全球气候治理模式受到全球大多数国家的认可。缔 约各国在应对全球气候变化中根据自己的情况提出一个实现气候变化目标的各自行动安排,各 国基于不同的国情,通过“自上而下”的方式执行各自的减排义务。国家自主贡献模式提升了全 球气候治理各缔约国的参与度,向各缔约国提出了“行动”和“支持”两种履行义务的法律标准。 中国在《中国国家计划自主贡献》中体现了一个负责任大国形象。     

A genomic regulatory network for development

Development of the body plan is controlled by large networks of regulatory genes. A gene regulatory network that controls the specification of endoderm and mesoderm in the sea urchin embryo is summarized here. The network was derived from large-scale perturbation analyses, in combination with computational methodologies, genomic data, cis-regulatory analysis, and molecular embryology. The network contains over 40 genes at present, and each node can be directly verified at the DNA sequence level by cis-regulatory analysis. Its architecture reveals specific and general aspects of development, such as how given cells generate their ordained fates in the embryo and why the process moves inexorably forward in developmental time.     

The Cambrian conundrum: early divergence and later ecological success in the early history of animals

Diverse bilaterian clades emerged apparently within a few million years during the early Cambrian, and various environmental, developmental, and ecological causes have been proposed to explain this abrupt appearance. A compilation of the patterns of fossil and molecular diversification, comparative developmental data, and information on ecological feeding strategies indicate that the major animal clades diverged many tens of millions of years before their first appearance in the fossil record, demonstrating a macroevolutionary lag between the establishment of their developmental toolkits during the Cryogenian [(850 to 635 million years ago (Ma)], and the later ecological success of metazoans during the Ediacaran (635 to 541 Ma) and Cambrian (541 to 488 Ma) periods. We argue that this diversification involved new forms of developmental regulation, as well as innovations in networks of ecological interaction within the context of permissive environmental circumstances.     

泰安市时代公园设计浅析

对山东省泰安市时代公园的规划设计进行解析，从专业角度详细地阐述了该公园在规划设计过程中彰显时代主题、实现功能与艺术的完美结合的设计思路，以期为同仁的设计抛砖引玉。     

Superiority, competition, and opportunism in the evolutionary radiation of dinosaurs

The rise and diversification of the dinosaurs in the Late Triassic, from 230 to 200 million years ago, is a classic example of an evolutionary radiation with supposed competitive replacement. A comparison of evolutionary rates and morphological disparity of basal dinosaurs and their chief "competitors," the crurotarsan archosaurs, shows that dinosaurs exhibited lower disparity and an indistinguishable rate of character evolution. The radiation of Triassic archosaurs as a whole is characterized by declining evolutionary rates and increasing disparity, suggesting a decoupling of character evolution from body plan variety. The results strongly suggest that historical contingency, rather than prolonged competition or general "superiority," was the primary factor in the rise of dinosaurs.     

Acoel flatworms: earliest extant bilaterian Metazoans, not members of Platyhelminthes

Because of their simple organization the Acoela have been considered to be either primitive bilaterians or descendants of coelomates through secondary loss of derived features. Sequence data of 18S ribosomal DNA genes from non-fast evolving species of acoels and other metazoans reveal that this group does not belong to the Platyhelminthes but represents the extant members of the earliest divergent Bilateria, an interpretation that is supported by recent studies on the embryonic cleavage pattern and nervous system of acoels. This study has implications for understanding the evolution of major body plans, and for perceptions of the Cambrian evolutionary explosion.     

小麦-冰草多粒新种质及其多粒性遗传分析

 【目的】探讨小麦-冰草多粒新种质3228多粒特性（>90粒/穗）的遗传及其利用价值。【方法】将该材料在5个不同小麦种植区进行种植,以评价该材料多粒特性的稳定性;采用主基因+多基因混合遗传模型分析方法对小麦-冰草多粒新种质3228（♀）×京4839（♂）的F2单株表型进行遗传分析。【结果】小麦-冰草多粒新种质3228多粒特性在不同环境下表现稳定,其穗粒数均大于90;小麦-冰草异源新种质3228与京4839（41粒左右/穗）F2群体遗传分析表明,多粒特性主要受1对主效基因控制,主基因的遗传率为27.81%,其加性效应是9.33;此外,在F2群体中,78.11%的单株穗粒数都高于京4839,表明3228中的多粒基因具有一定的显性效应。【结论】小麦-冰草多粒新种质3228多粒特性具有较好的环境稳定性,其在遗传上主要受1对主基因控制,有望利用该多粒基因通过提高穗粒数实现小麦高产育种。     

黑河流域下游天然植被生态需水预测

根据对黑河下游天然植被生态状况的分忻，对不同水平年提出了5个生态恢复方案，计算预测了各方案的生态需水量．提出了推荐生态恢复方案。     

Shaping the vertebrate body plan by polarized embryonic cell movements

Polarized cell movements shape the major features of the vertebrate body plan during development. The head-to-tail body axis of vertebrates is elongated in embryonic stages by "convergent extension" tissue movements. During these movements cells intercalate between one another transverse to the elongating body axis to form a narrower, longer array. Recent discoveries show that these polarized cell movements are controlled by homologs of genes that control the polarity of epithelial cells in the developing wing and eye of the fruit fly, Drosophila.     

蛋白质组学在发育生物学研究中的应用

发育生物学主要研究生物体从精子和卵子的发生、受精、胚胎发育、生长到衰老、死亡的规律。一个生物体的蛋白质随发育阶段、特定组织等变迁而不断变化,蕴藏着巨大的动态的生命活动的信息量,利用蛋白质组学技术可从分子水平了解生物体的发育调控、发育异常等的机制,具有重要的意义和广泛的应用前景。综述了蛋白质组学主要研究方法及其在动物和植物发育生物学中的应用。     

Apoptotic molecular machinery: vastly increased complexity in vertebrates revealed by genome comparisons

A comparison of the proteins encoded in the recently (nearly) completed human genome to those from the fly and nematode genomes reveals a major increase in the complexity of the apoptotic molecular machinery in vertebrates, in terms of both the number of proteins involved and their domain architecture. Several components of the apoptotic system are shared by humans and flies, to the exclusion of nematodes, which seems to support the existence of a coelomate clade in animal evolution. A considerable repertoire of apoptotic protein domains was detected in Actinomycetes and Cyanobacteria, which suggests a major contribution of horizontal gene transfer to the early evolution of apoptosis.     

Buddenbrockia is a cnidarian worm

A major evolutionary divide occurs in the animal kingdom between the so-called radially symmetric animals, which includes the cnidarians, and the bilaterally symmetric animals, which includes all worm phyla. Buddenbrockia plumatellae is an active, muscular, parasitic worm that belongs to the phylum Myxozoa, a group of morphologically simplified microscopic endoparasites that has proved difficult to place phylogenetically. Phylogenetic analyses of multiple protein-coding genes demonstrate that Buddenbrockia is a cnidarian. This active muscular worm increases the known diversity in cnidarian body plans and demonstrates that a muscular, wormlike form can evolve in the absence of overt bilateral symmetry.     

Asymmetric coevolutionary networks facilitate biodiversity maintenance

The mutualistic interactions between plants and their pollinators or seed dispersers have played a major role in the maintenance of Earth's biodiversity. To investigate how coevolutionary interactions are shaped within species-rich communities, we characterized the architecture of an array of quantitative, mutualistic networks spanning a broad geographic range. These coevolutionary networks are highly asymmetric, so that if a plant species depends strongly on an animal species, the animal depends weakly on the plant. By using a simple dynamical model, we showed that asymmetries inherent in coevolutionary networks may enhance long-term coexistence and facilitate biodiversity maintenance.     

谷子品种的农艺性状演变分析

采用灰色关联度法分析了华北地区 2 0个谷子代表品种的农艺性状演变趋势。结果表明 :谷子株高逐渐降低 ,成穗率明显提高 ,穗长、单穗重、单穗粒重、千粒重发展协调 ,产量大幅度提高。谷子育种今后应以中秆中穗类型为目标 ,栽培管理应在提高成穗率的基础上主攻千粒重。     

A mouse macrophage factor induces head structures and organizes a body axis in Xenopus

Soluble peptide factors have been implicated as the agents responsible for embryonic inductions in vertebrates. Here, a protein (PIF) secreted by a mouse macrophage cell line is shown to change the developmental fate of Xenopus embryonic cells. Exposure to PIF causes presumptive ectodermal explants to form anterior neural and mesodermal tissues, including brain and eye, instead of ciliated epidermis. In addition, the induced tissues are organized into a rudimentary embryonic axis. These results suggest that PIF or a closely related molecule is involved in inducing anterior structures and organizing the frog body plan.     

Evolution of a polyphenism by genetic accommodation

Polyphenisms are adaptations in which a genome is associated with discrete alternative phenotypes in different environments. Little is known about the mechanism by which polyphenisms originate. We show that a mutation in the juvenile hormone-regulatory pathway in Manduca sexta enables heat stress to reveal a hidden reaction norm of larval coloration. Selection for increased color change in response to heat stress resulted in the evolution of a larval color polyphenism and a corresponding change in hormonal titers through genetic accommodation. Evidently, mechanisms that regulate developmental hormones can mask genetic variation and act as evolutionary capacitors, facilitating the origin of novel adaptive phenotypes.