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关键词： 实验动物   检测   微生物学   环境  

关键词： Shrimp   Larval development   Fresh water   Salinity   Metamorphosis   Ecological genetics   Physiology   Embryology  

摘要： The freshwater shrimps belonging to the atyid geus Caridina have a great potential as experimental biological material amongst decapod crustaceans due to the following features: 1. Easy availability throughout the year. 2. Occurrence in practically all kinds of inland and coastal water bodies. 3. Convenient size to handle and maintain in the laboratory. 4. Natural hardiness to salinity, temperature, low dissolved oxygen levels and desiccation. 5. Omnivorous/scavenging feeding habits. 6. Early muturation. 7. Breeding throughout the year with rather short interbreeding periods. 8. Good fecundity. 9. Eggs fairly large, hardy, easy removable, and hatching in vitro. 10. Metamorphosis representing all types of larval developmental patterns. 11. Successful rearing, of larvae in fresh to saline waters using technique with almost 100% survival rate and scope for cross-breeding. All these properties of Cardina sufficiently merit their consideration as a suitable biological tool for studies in such diverse disciplines as ecology, physiology, reproductive biology, embryology, genetical engineering, etc.

关键词： DNA   转基因动物   分子生物学  

摘要： 分子生物学领域以惊人速度不断获得新的发现，加深了人们对于实验动物和家畜基因工程潜力的理解。近期一些重要的技术，如重组ＤＮＡ技术，基因克隆技术，基因表达的分子技术以及核酸和蛋白的序列分析技术，已获得进一步完善。这些分子技术与重组基因转移到活细胞和受精卵技术相结合，可以生产转基因小鼠和其他转基因动物，其应用前景是无限的。

关键词： 啮齿目   动物   实验工作   动物学   寄生物   分类系统   微生物学   检验   检验  

标准号: GB 14922-1994

关键词： 水貂   犬   猫   云豹   细小病毒   生物学  

摘要： Amphibian metamorphosis has attracted the interest of developmental biologists for decades. Its dependency on thyroid hormone (TH) makes if a unique system to study postembryonic organ development as well as hormone action. Recent cloning of the TH receptors and the demonstration that these receptors are transcription factors suggest that TH controls metamorphosis by regulating a cascade of gene expression. Systematic analyses of TH early-response genes in three very different organs (the tail, limb, and intestine) have been conducted. The developmental profiles of their expression and their identities suggest that these genes play important roles during metamorphosis, for en:ample, controlling the expression of intermediate and/or TH late-response genes. lit addition, the gene-regulation program that governs amphibian metamorphosis as revealed by these and related studies appears to resemble that induced by the hormone ecdysone during insect metamorphosis. Further investigation on how the hormone regulates early-response genes and how the products of these genes, in turn, participate in tissue remodeling will provide a better understanding of the molecular basis of the hormonal control of metamorphosis.

关键词： LORETO PERU   GAME HUNTING   SUSTAINABLE USES   MAMMALS   ECONOMICS  

摘要： Rural inhabitants in Amazonia can overexploit many mammalian species by game hunting, and tropical forests lose their value as a source of game meat when mammal populations decline. Implementing a sustainable hunt should reduce overexploitation of animals, and therefore help retain the value of intact Amazonian ecosystems. Rural folk in the Tahuayo region of the Reserva Comunal Tamshiyacu-Tahuayo of northeastern Peru appear to be overharvesting primates and lowland tapir Tapirus terrestris, but are apparently not overexploiting artiodactyls and large rodents. Converting the current overhunting in Tahuayo to a more sustainable harvest would require cessation of hunting of overexploited species and the setting of artiodactyl and large rodent harvests at or below current levels. Costs of implementing a more sustainable hunt in Tahuayo would incur a 26% reduction of economic benefits for hunters and reduce the extraction of mammalian biomass by 35%.