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关键词： 《解剖学及组织胚胎学》   教材  

关键词： 先天性双侧唇裂   副鼻小柱畸形   病例报告   组织胚胎学   整复术  

摘要： 在唇裂的伴发畸形中以腭裂或颌裂常见,而双侧发生唇裂且伴有副鼻小柱畸形者罕见,笔者诊治1例报告如下.

关键词： 多媒体CAI   应用   教学  

摘要： 应用多媒体 CAI课件辅助教学 ,是优化教学环境 ,提高教学效率的有效途径 ,本文结合组织学与胚胎学教学实际 ,阐述在教学中应用多媒体技术辅助教学的必要性 。

关键词： 组织学   胚胎学   教学资源   Internet网  

摘要： 随着Internet网在我国的开通,为我们提供了一个巨大的信息资源库以及快速获取和传递信息的手段.我们在进入Internet网以来,尝试各种途径搜索与组织学与胚胎学教学有关的内容,获取了大量资料,使我们感到网络查询不仅方便,而且能获得图文并茂的信息资源.但对于一个上网新手,面对庞大资源常不知从何下手,要想快速、准确地获取信息需要一段时间的摸索,这可能会造成时间和费用的浪费.为了使上网者少走弯路,尽快掌握这一工具,充分利用其丰富资源为教学服务,现将我们的应用体会介绍如下.

关键词： perichromatin granules   RNP   notochord   differentiation   nucleus  

摘要： The ultrastructure of notochordal cells and the quantitative changes of nuclear mRNA-containing particles were studied in several stages of the development of the chick embryo. The modifications in the frequency of perichromatin granules (PCG) were analyzed in embryos at 24 hr to 10 days of incubation (stages 6-36 of Hamburger and Hamilton). The ultrastructural and morphometric data show that notochordal cells undergo changes that can be systematized in four periods. Very early notochordal cells (stages 6-11), are characterized by the presence of large nucleoli and abundant PCG, traits probably related to the frequent mitotic division and the expression of inductive signals reported in numerous papers. During the second period (stages 16-21) the number of PCG and the size of the nucleolus decrease. These changes are coincident with the beginning of vacuolization. In the third period (stages 21-30), the notochordal cells undergo a second cytodifferentiation characterized by a large increase of cytoplasmic vacuolization and secretion of materials that thicken the perichordal sheath. During this period, the nucleolus becomes smaller and the number of PCG increases. Similar features were previously described during functional maturation of embryonic neurons and striated fibers at synaptogenesis, and epidermal cells. The fourth period, beginning at stage 30, is characterized by the decrease of the density of PCG and of the nucleolar volume and corresponds to cessation of mitosis and cell degeneration. Anat Rec 259:113-123, 2000. (C) 2000 Wiley-Liss, Inc.

关键词： 第三版解剖学及组织胚胎学   教材   商榷   专业特色  

关键词： 胎盘   胚胎组织   残留子宫内   超声波诊断  

摘要： 我院自1996年6月～1999年2月共收治胎盘及胚胎组织残留子宫内患者47例,现将其超声表现总结分析如下。1 资料与方法1.1 一般资料本组47例中年龄最小者18岁,最大者52岁,平均年龄为35岁;47例中人工流产后12例,药物流产后26例,中孕引产后5例,双胎足月分娩后1例。

关键词： pigment pattern   cell lineage   pigment cell   differentiation  

摘要： Melanophore lineage during embryogenesis of Xenopus laevis was traced using the overexpression of a biogenic marker, green fluorescent protein (GFP). Two different approaches mere applied after injection of GFP mRNA thence a marker construct) into each blastomere at the 16-cell stage. In in vivo experiments, the embryos injected with a marker construct were grown until stage 45, in which melanophores mere distributed over the whole body and were good enough for checking GFP expression at their migratory destination. In in vitro experiments, neural tubes of the embryos injected with a marker construct were isolated and cultured at stage 21 to examine by virtue of GFP expression how neural crest cells differentiate into melanophores. The results obtained from both in vivo and in vitro experiments indicated the following: 1) selected animal blastomeres vastly contribute to the development of melanophores, whereas other animal blastomeres do so slightly at a limited pace;and 2) vegetal blastomeres never contribute to melanophores in normal development, whereas certain vegetal blastomeres have a potential to give rise to melanophores in vitro. The analyses using GFP also disclosed that the dorsal and ventral epidermis derive from the restricted animal blastomeres in the normal development. Since the dorso-ventrality of the epidermis has been inseparably coupled with integumental pigmentation, the clonal organization of the epidermis observed in the present study is discussed in the light of pigment pattern formation attributed by melanophores.

关键词： Zea mays   embryo-specific   protoderm   shoot meristem   radial organization  

摘要： Using confocal laser scanning microscopy we have characterized early and intermediate stages of maize wild-type embryogenesis and compared to mutant development of four different embryo-specific mutations, emb*-8518, emb*-8521, emb*-8537, and emb*-8542. Confocal laser scanning microscopy is well suited to study embryo development in maize in a nondisruptive manner from shortly after fertilization to late stages in embryogenesis. The analysis of the mutant morphology indicated that two of the recessive mutations, emb*-8518 and emb*-8521, cause an early developmental arrest in the proembryo/early transition stage: mutant embryos are unable to enter the morphogenetic phase of embryogenesis. In contrast, homozygous emb*-8537, and emb*-8542 embryos progress at least to the coleoptilar stage and sometimes establish a functional shoot meristem that can determine leaf primordia. The morphological characterization of mutants was confirmed by analysis of the expression pattern of three different marker genes: Lipid transfer protein 2, Zea mays Outer Cell Layer 1, and Knotted 1. Our data indicate that both emb*-8518 and emb*-8521 mutant embryos are impaired in restriction of ZmOCL1 transcripts to the embryonic protoderm and therefore fail to establish a normal radial organization. In contrast, emb*-8537 and emb*-8542 embryos exhibit the wild-type pattern and proceed in development to the formation of a shoot apical meristem and the establishment of bilateral symmetry.

关键词： 氨基酸序列   碱基序列   DNA引物   DNA   互补   基因表达调控   植物   同源盒结构域蛋白质类/遗传学   分子序列数据   逆转录聚合酶链反应   种子/遗传学   序列同源性   氨基酸   玉米/胚胎学   玉米/遗传学  

摘要： A family of homeo box genes with cell layer-specific expression patterns defining subdomains of the embryo and certain meristems has been isolated from maize. These genes encode proteins from the class of plant specific homeo domain-leucine zipper (HD-Zip) transcription factors containing the previously described ZmOCL1 protein, and have been designated ZmOCL2, ZmOCL3, ZmOCL4 and ZmOCL5. ZmOCL3, ZmOCL4 and ZmOCL5, like ZmOCL1, showed essentially L1 or epidermis-specific expression. However, each gene was expressed in a distinct region of the embryonic protoderm during early development, with ZmOCL3 showing suspensor-specific expression, ZmOCL4 transcripts being localized to the adaxial face of the embryo proper and ZmOCL5 showing a more abaxial expression pattern. All three genes were also expressed in vegetative, inflorescence and floral apices, although ZmOCL3 transcripts were excluded from meristems and very young organ primordia. In contrast, ZmOCL2 expression was entirely meristem-specific and was excluded from the L1 layer, appearing instead to be largely restricted to a cell layer directly beneath the L1, especially in floral meristems. This expression pattern is unprecedented and may indicate that cell-layer organization in maize meristems is more complex than that suggested by the classical L1/L2 (outer cell layer/inner cell mass) model. These differing expression patterns indicate that the members of the HD-ZipIV family of maize may not only play roles in defining different regions of the epidermis during embryonic development, but could also be responsible for maintaining cell-layer identity in meristematic regions.