共查询到20条相似文献,搜索用时 31 毫秒
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植物的受精作用 第五讲 受精的控制 总被引:1,自引:0,他引:1
自本世纪二十年代开始,已开展了一些有关人工控制受精的试验。1950年以前的工作,Maheshwari (1950)已收集在他所著的《被子植物胚胎学引论》一书中。在最近的三十多年,由于对不亲和性饥理的知识的提高,创立了更多的克服不亲和性的有效方法。本文选择蒙导花粉法、蕾期授粉、电助授 相似文献
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被子植物的受精工程技术何龙飞,王爱勤(广西农业大学农学系,南宁530005)被子植物受精工程是利用分离的精子和卵细胞进行体外受精,形成人工合子,再培养成植株而进行品种改良或物种创造的过程,具有重要的理论和实践意义。近年来取得了重大的进展,如雄性生殖单... 相似文献
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哺乳动物的受精(Mammalian Fertilization)是两性配子(精子和卵子)相结合而形成合子的过程,它标志着胚胎发育的开始,也即是一个新生命的起点。受精是生物学家饶有兴味的课题。因为它不仅涉及到一个理论问题,更重要的是当今节育和不育的世界性问题尚未解决,因此,受精的重要性是不言而喻的。当然,受精是一个极其复杂的生命现象,涉及到两性配子的发育和成熟、精子获能、顶体反应、精卵激活、精子 相似文献
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Edward G. Pollock 《Planta》1970,92(1):85-99
Summary Methods are described for the collection, treatment and uniform discharge of large quantities of gametes, and a measure of fertilization control in the monoecious brown alga, Fucus distichus. Fertilization was examined using the techniques of blister-formation, gamete separation experiments, and electron microscopy. Sperm enter the freshly-discharged egg packets through a mesochite pore and juxtaposition with the eggs early. However, experimental and thinsection data indicate that fertilization does not occur until the eggs dissociate from the mesochite and round up. Hence, the egg surface appears to undergo three functional changes following its release from the thallus: (1) a pre-dissociation state which inhibits fertilization within the mesochite; (2) a dissociation state when fusion of gametes is possible; and (3) a post-fertilization state characterized by the formation of extraneous coats. As the egg is activated by the sperm a nonmembranous layer appears to detach from the egg surface to form an activation layer. This is augmented by fibrous units to function as a fertilization barrier which ultimately thickens to form the cell wall. The area between the eggs within the egg packet is characterized by the presence of fibrous and particulate substances which are continuously given off through the egg surface. These apparently play a functional role in the sequential stages of fertilization in Fucus. These observations are discussed in terms of analogies with fertilization in the sea urchin.This work was supported by a Lalor Foundation Research Fellowship at Friday Harbor Biological Laboratories, University of Washington, and by a National Science Foundation Science Faculty Fellowship to the Swiss Federal Institute of Technology, Zürich, Switzerland. 相似文献
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Paul M. Wassarman 《Genesis (New York, N.Y. : 2000)》1999,25(2):83-86
Fertilization in mammalian and nonmammalian organisms has many features in common. These features include a final maturation phase for sperm and eggs, species‐specific binding of sperm to eggs, penetration by sperm of one or more extracellular coats surrounding eggs, fusion of sperm and eggs, and activation of eggs. Implicit in this are a variety of basic molecular events, including receptor‐ligand interactions, signalling cascades, specific proteolysis, and nuclear transformations. Here, several of these events are addressed for fertilization in animals as diverse as starfish and mice. Dev. Genet. 25:83–86, 1999. © 1999 Wiley‐Liss, Inc. 相似文献
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L Santella F Vasilev JT Chun 《Biochemical and biophysical research communications》2012,425(3):588-594
For more than 150years, echinoderm eggs have served as overly favored experimental model systems in which to study fertilization. Sea urchin and starfish belong to the same phylum and thus share many similarities in their fertilization patterns. However, several subtle but fundamental differences do exist in the fertilization of sea urchin and starfish, reflecting their phylogenetic bifurcation approximately 500 million years ago. In this article we review some of the seminal and recent findings that feature similarities and differences in sea urchin and starfish at fertilization. 相似文献