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关键词： 人体组织学：人体胚胎学   成人教育：高等教育   教材  

ISBN: (纸本)7810503081

摘要： 本书共22章，包括绪论、细胞学、组织学和胚胎学4个部分，教材内容力求介绍以医学大专学生必须掌握的基本理论知识为主，保持学科自身的系统性。

关键词： S-pyogenes   mouse air sac   chicken embryo   M and M-related proteins   isogenic mutants  

摘要： An M2 streptococcal isolate and isogenic mutants in which either the emm or mrp gene was insertionally inactivated were tested for virulence using either a mouse model or a chicken embryo model. The results of the studies using the mouse model demonstrated that neither the emm nor mrp gene products had a significant effect on virulence when mice were challenged via the i.p. route. However, when the bacteria were injected into the skin the emm gene product was identified as a virulence factor. In parallel studies in the chicken embryo model the mrp gene product was found to be a major virulence factor, while a minor contribution to virulence could also be attributed to the emm gene product. The importance of these gene products to virulence was noted when the chicken embryo were injected either i.v or when the bacteria were placed on top of the chorioallantoic membrane. The direct comparison of a single wild type group A organism and its paired isogenic mutants in two animal models suggests that different combinations of bacterial factors are required to overcome host defense strategies associated with different animal species. (C) 1997 Academic Press Limited.

关键词： Gene Expression Regulation   Developmental   Transcription Factors   Zebrafish Proteins   Amino Acid Sequence   Animals   Comparative Study   Conserved Sequence   DNA-Binding Proteins   Embryo   Nonmammalian   Exons   Homeodomain Proteins   Introns   Research Support   Non-U.S. Gov't   Research Support   U.S. Gov't   Non-P.H.S.   Research Support   U.S. Gov't   P.H.S.   Zebrafish  

摘要： To under-stand the relationship between the expression and the genomic organization of the zebrafish dlx genes, we have determined the genomic structure of the dlx2 and dlx4 loci. This led to the identification of the zebrafish dlx1 and dlx6 genes, which are closely linked to dlx2 and dlx4, respectively. Therefore, the inverted convergent configuration of Dlx genes is conserved among vertebrates. Analysis of the expression patterns of dlx1 and dlx6 showed striking similarities to those of dlx2 and dlx4, respectively, the genes to which they are linked. Furthermore, the expression patterns of dlx3 and dlx7, which likely constitute a third pair of convergently transcribed genes, are indistinguishable. Thus, the overlapping expression patterns of linked Dlx genes during embryonic development suggest that they share cis-acting sequences that control their spatiotemporal expression. The evolutionary conservation of the genomic organization and combinatorial expression of Dlx genes in distantly related vertebrates suggest tight control mechanisms that are essential for their function during development. (C) 1997 Academic Press.

关键词： Animals   Aphidicolin   Cell Nucleus   DNA   DNA Replication   Digoxigenin   Enzyme Inhibitors   Female   Male   Mice   Mice   Inbred C57BL   Mice   Inbred CBA   Microinjections   S Phase   Transcription   Genetic   Uridine Triphosphate   Zygote  

摘要： We have analyzed the spatial and temporal relationship between transcription and replication sites during the first cell cycle in mouse embryos. Embryos were microinjected with both 5-bromouridine-5'-triphosphate and digoxygenin-11-deoxyuridine-5'-triphosphate to visualize transcription and replication sites respectively. We detected six different phases of replication during S phase and dated the onset of zygotic transcription at the end of the S phase. Using confocal microscopy, we showed that there is essentially no colocalization of replication and transcription sites at this stage of development. Moreover, studies on aphidicolin-treated embryos demonstrated that inhibition of DNA replication does not hinder transcriptional activation at the 1-cell stage. (C) 1997 Academic Press.

关键词： 人体组织学:人体胚胎学   学科:医学教育   学科:教材   人体胚胎学:人体组织学   人体解剖学  

ISBN: (纸本)7534110939

关键词： 医学教育   组织胚胎学   学生   调查  

关键词： 龙眼   胚性愈伤组织   体胚发生   高频率  

摘要： 比较了龙眼不同类型胚性愈伤组织、品种、蔗糖质量浓度、有机附加物、生长调节剂、光照度等因素对龙眼胚性愈伤组织体胚诱导的影响.结果表明,在优化的体胚发生条件下,选择适宜的胚性愈伤组织类型,可获得龙眼胚性愈伤组织的高频率体细胞胚胎发生.在低质量浓度蔗糖(≤30 g·L^(-1))和黑暗条件下,松散型胚性愈伤组织的体胚分化频率为100%,并且发生数量可达每克1万个左右.

关键词： Allantois   Animals   Anoxia   Arteries   Blood Flow Velocity   Body Weight   Chick Embryo   Chorion   Comparative Study   Female   Fetal Anoxia   Heart   Heart Rate   Fetal   Oxygen   Pregnancy   Regional Blood Flow   Time Factors  

摘要： Hypoxia in the mammalian fetus produces cardiovascular changes, such as bradycardia, systemic hypertension, and changes in heart rate variability. This response was studied in 140 chick embryos ranging from stage 34 to stage 42 (d 9-16 of the 21-d incubation), by measuring the changes in mean chorioallantoic artery blood flow (CABF) and heart rate for 5 min in two levels of hypoxia (group 1;n = 90;100% N-2) or (group 2;n = 50;5% O-2). Eggs were opened at the air cell and placed in a small plexiglass holder, which had a continuous gas flow of an O-2/N-2 mixture (5 L/min), at 38 degrees C and 60% humidity. The chorioallantoic artery was placed in the lumen of a flow probe to measure mean CABF, heart rate, peak flow, and blood flow acceleration. After baseline measurements, the gas mixture was changed to 100% N, or 5% O-2 in N-2 for 5 min. Mean CABF and heart rate decreased significantly in both groups (Wilcoxon paired sample test, p < 0.05). This response was more pronounced with the development of the chick embryo. Chorioallantoic artery peak flow (mL/min) and CABF acceleration (mL/s(2)) increased with incubation time and decreased during periods of hypoxia. During recovery, heart rate returned to baseline levels, whereas mean CABF showed an overshoot. The initial decrease in mean CABF and heart rate was similar in both groups. The cardiovascular response to hypoxia in the chick embryo is similar to the response in the mammalian fetus. The more pronounced response in the more developed chick embryo may represent a maturation of cardiovascular control.

摘要： Congenital transmission of reticuloendotheliosis virus (REV) is known to occur when one of the parents in either tolerantly infected or viraemic;however little attention has been paid to replication of the virus within the embryo itself. In this study five non-defective and one replication-defective strain of REV were inoculated into the yolk sac of 6-day-old embryonated eggs. With the exception of one non-defective strain, the others induced embryonic deformation or lesions that were apparent on the day of hatching. Replicative integration of the provirus was determined for several tissues of each embryo by the polymerase chain reaction employing a set of primers specific for the long terminal repeat. Indirect immunofluorescent detection of whole virus was performed on the same tissues in parallel. A variation in replication was found among the strains and between embryos inoculated with the same strain of virus, therefore, the results for each virus strain were expressed as cumulative values. The liver and spleen were the most commonly affected organs, while the bursa of Fabricius and thymus supported viral replication to a lesser degree. Detection of proviral DNA in blood was evidence that the chicks had been congenitally infected. Such an infection would likely lead to tolerance. Isolates REV-S and REV-D were found to replicate to the highest extent, and they also caused lesions in the commercial type of embryonated eggs, while REV-S and mainly the REV-T prototype were pathogenic for the SPF embryonated eggs.