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关键词： 分子生物学技术   动物营养学   基因工程   新品种   调节机理   生长性能   转基因技术   生理活性物质   营养素   研究领域  

摘要： 基因工程专家研究认为,以基因工程为核心的分子生物学技术应用于动物营养学研究领域。具有广阔的前途。分子生物学技术不仅为动物营养学研究提供了一套全新的技术和方法,而且在基因水平上解决许多养殖对象机体生理病理变化、营养素的新陈代谢调节机理以及与机体相互关系等问题。专家们预测,随着转基因技术的日趋完善,培育出的各种生长性能优越的养殖新品种将会不断出现;另外,用转基因种来大量生产各种生理活性物质,也将成为现实。21世纪是高新技术水产增养殖业应用大发展的时代。

关键词： 发育生物学   理想动物模型   斑马鱼   生物学特征   脊椎动物   突变分析  

摘要： 本文介绍了斑马鱼的基本生物学特征 ,并与小鼠对照对其在发育生物学中应用的优点进行分析 ,阐述了斑马鱼在发育生物学领域的应用和研究概况 。

关键词： Franklinothrips   pupation biology   harvesting   shipping  

摘要： In the laboratory, 82-99% of late second instar Franklinothrips orizabensis Johansen larvae abandoned avocado branches and artificial branches constructed of wooden dowels and were recovered below branches trapped on tangle foot coated plastic sheets, suggesting a preference by this life stage for selection of pupation sites beneath host plants. Of three media tested (coarse and fine vermiculite, and parafilm cones) for harvesting K orizabensis pupae in cocoons, parafilm cones were most easily harvestable from colonies, and 44% of deployed late second stage larvae that were recovered used parafilm cones for pupation in experimental cages. Harvesting and shipping trials using aspirated adult F: orizabensis or pupae in parafilm cones showed significant differences in survivorship when held in the laboratory or shipped round trip from Riverside, California to Amherst, Massachusetts. Survivorship of aspirated adults was reduced on average by 41% following shipping, and mortality was highest for adult males. Transit survivorship was increased by 53% if F. orizabensis were shipped as cocoons in parafilm cones. Inclusion of ice packs in polystyrene boxes did not significantly increase survivorship rates for F. orizabensis adults or pupae that were either retained in the laboratory or shipped. This result may have been an artifact resulting from the time of year (i.e., May and temperatures were moderately cool) when shipping trials were conducted.

关键词： Animals   Body Constitution   Body Weight   China   Ear Ossicles/anatomy & histology   Evolution   Fossils   Jaw/anatomy & histology   Mammals/anatomy & histology   Mammals/classification   Phylogeny   Phylogeny   Skull/anatomy & histology   Vertebrates/anatomy & histology   Vertebrates/classification  

摘要： The last two decades have been exhilarating for paleontologists andevolutionary biologists seeking to unravel phylogenetic relationships among living and extinctmammals. Stunning fossils have been unearthed from key locations worldwide and new methods havefacilitated the comparison of these fossils with their living counterparts. The fossil reported byLuo et al. (1) on page 1535 of this issue is the latest gem in this string of paleontologicalpearls. They describe a beautifully preserved skull of a new synapsid taxon called Hadrocodium(synapsids are the group of legged vertebrates to which mammals belong), unearthed from the famousEarly Jurassic (approx 195 million years old) Lufeng deposits of Yunnan Province in China. Althoughthe last 65 million years of Earth history (the Cenozoic Era) are often regarded as "the age ofmammals," the major branches of the mammalian evolutionary tree diverged tens of millions of yearsearlier, during the Mesozoic Era (see the figure). We have known about fossils of Mesozoic mammalsfor about 200 years. But it is only recently that significant numbers of reasonably complete skullsand skeletons have become available. Prior to this, information was limited to what could be gleanedfrom skeletal bits and pieces, such as teeth and jaw fragments. Indeed, much of our knowledge aboutmammalian evolution stems from analyses of the highly specialized teeth for which mammals arenoted. The availability of exquisitely preserved skulls and skeletons of many early mammalianlineages has diminished the influence of this tooth-centric perspective, leading to the emergence ofa highly integrated understanding of mammalian phylogeny.

关键词： 传能线密度   碳离子   哺乳动物细胞   存活率   微核率   染色体畸变   体外培养   细胞培养  

摘要： 目的　研究不同传能线密度 (LET)的重离子对体外培养细胞存活率、微核率和染色体畸变的效应。方法　用集落形成法研究细胞的存活情况 ,观察统计细胞微核率和染色体结构的变化。结果　①细胞存活 :不同LET碳离子引起细胞失活效应由大到小的顺序依次为 12 5 ,2 0 0 ,70 0keV μm。②细胞微核 :相同剂量下 ,2 0 0keV μm碳离子所致微核率高于 70 0keV μm时的结果。③染色体畸变 :可看到多种染色体结构变异。结论　在本实验中 ,LET为 12 5keV μm的碳离子引起的失活效应最大 ,2 0 0keV μm碳离子引起的微核率高于 70 0keV

关键词： endocrine disrupters   estrogen receptor   evolution   diet   fertility   plant-herbivore coevolution   sex steroids  

摘要： Hormone disruption is a major, underappreciated component of the plant chemical arsenal, and the historical coevolution between hormone-disrupting planes and herbivores will have both increased the susceptibility of carnivores and diversified the sensitivities of herbivores to manmade endocrine disrupters. Here I review diverse evidence of the influence of plant secondary compounds on vertebrate reproduction, including human reproduction. Three of the testable hypotheses about the evolutionary responses of vertebrate herbivores to hormone-disrupting challenges from their diet are developed. Specifically, the hypotheses are that a) vertebrate herbivores will express steroid hormone receptors in the buccal cavity and/or the vomeronasal organ;b) absolute sex steroid concentrations will be lower in carnivores than in herbivores;and c) herbivore steroid receptors should be more diverse in their binding affinities than carnivore lineages. The argument developed in this review, if empirically validated by support for the specific hypotheses, suggests that a) carnivores will be more susceptible than herbivores to endocrine-disrupting compounds of anthropogenic origin entering their bodies, and b) diverse herbivore lineages will be variably susceptible to any given natural or synthetic contaminant. As screening methods for hormone-disrupting potential are compared and adopted, comparative endocrine physiology research is urgently needed to develop models that predict the broad applicability of those screening results in diverse vertebrate species.

关键词： 医学生物学   实验动物   现状   应用  

摘要： 本文阐述了实验动物在医学生物学研究领域中的应用现状。

关键词： comparative developmental biology   cerebral neocortex   forebrain   neuromeres   evolution   body plan  

摘要： Little is known about how unique features in a species can emerge along the conserved body plan beyond species. For example, mammals, including human beings, have acquired the neocortex with distinct function and morphology. Here we review current topics in comparative developmental biology of vertebrate brains, especially focusing on the cerebral neocortex as a suitable model for considering species-specific aspects. (C) 2001 Elsevier Science Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

关键词： .oligodendrocytes   central nervous   myelin sheath   myelination   Pham-Dinh   Specific Components   Glial Network   Node of Ranvier   nbsp Myelin  

摘要： Oligodendrocytes, the myelin-forming cells of the central nervous system (CNS), and astrocytes constitute macroglia. This review deals with the recent progress related to the origin and differentiation of the oligodendrocytes, their relationships to other neural cells, and functional neuroglial interactions under physiological conditions and in demyelinating diseases. One of the problems in studies of the CNS is to find components, i.e., markers, for the identification of the different cells, in intact tissues or cultures. In recent years, specific biochemical, immunological, and molecular markers have been identified. Many components specific to differentiating oligodendrocytes and to myelin are now available to aid their study. Transgenic mice and spontaneous mutants have led to a better understanding of the targets of specific dys- or demyelinating diseases. The best examples are the studies concerning the effects of the mutations affecting the most abundant protein in the central nervous myelin, the proteolipid protein, which lead to dysmyelinating diseases in animals and human (jimpy mutation and Pelizaeus-Merzbacher disease or spastic paraplegia, respectively). Oligodendrocytes, as astrocytes, are able to respond to changes in the cellular and extracellular environment, possibly in relation to a glial network. There is also a remarkable plasticity of the oligodendrocyte lineage, even in the adult with a certain potentiality for myelin repair after experimental demyelination or human diseases.

关键词： Delphinium montanum   conservation   animal predation   reproductive biology   allozyme electrophoresis  

摘要： Delphinium montanum is a larkspur endemic to the Pyrenees. It has c. 4000 individuals and is classified as vulnerable following the IUCN categories. Pollination ecology results demonstrated that it is strictly dependent on pollinator activity (mainly bumblebees) to set seeds. Genetic diversity estimated by allozyme variation at 7 loci showed quite high levels of variation related to its polyploidy. Predation by Pyrenean chamois (Rupicapra rupicapra pyrenaica), first detected in 1993, caused a continuous loss of > 90% of seed set in a protected area. The maintenance of high genetic diversity suggests the buffer effect of polyploidy and seed bank strategy to counter animal grazing, but long-term effects on conservation are expected. These results stressed: (1) the need for a plan to monitor this animal-plant interaction;and (2) the need to monitor closely the population number of individuals of certain protected animal species in Natural Reserves, particularly if ecological competition has been disturbed by human intervention. (C) 2001 Elsevier Science Ltd. All rights reserved.