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中华大蟾蜍和花背蟾蜍染色体同源性研究 总被引:2,自引:0,他引:2
本文以培养 扣华大蟾蜍、花背蟾蜍的外周血淋巴细胞为实验材料,采用BrdU南极洲民法和胸苷标记的方法,获得了中华大蟾蜍与花背蟾蜍析搞分辨晚复制带,确定了中华大蟾蜍每一染色体的特征性晚复制区,并就中华大蟾蜍与花背蟾蜍的晚复纹带进行了精确比较,发现中华大蟾蜍与花背蟾蜍的染色体之间具有极高同源性,该结果说明,在相同的培养条件下,只要BrdU掺入S期的时间较为统一,显示复制带的条件基本一致的情况下,利用复 相似文献
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蟾蜍种间核移植胚胎发育早期LDH同工酶的表现 总被引:2,自引:1,他引:1
利用聚丙烯酰胺凝胶电泳,对中华大蟾蜍(Bufo bufo比gargarizans)与花背蟾蜍(Bufo raddei)种间核移植胚胎发育早期六个不同阶段中全胚胎的乳酸脱氢酶(LDH)同工酶进行了分析。酶谱比较的结果表明:在正、反种间移核胚胎中,供体核LDH基因的活动开始表现于尾芽胚期;此前,杂种胚胎中LDH同工酶谱类型与受体一致。 相似文献
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电脉冲介导金鱼囊胚细胞融合及其发育能力的研究 总被引:1,自引:0,他引:1
本实验首次成功地利用电脉冲介异法使金鱼的囊胚细胞融合,融合率高于95%,并通过细胞核移植方法,将融合细胞的细胞核移入金鱼成熟未受精的去核卵内,以了解融合后细胞核的发育能力。实验中共移植111个细胞核,得44个囊胚、7个原肠胚和1条活了8天的幼鱼(因不进食而死亡)。并对移核后发育至囊胚的胚胎用静态光度计测定了DNA含量,共测定了11个移核胚胎的细胞,其中9个移核囊胚细胞核的DNA含量增加,这一结果证明:利用电脉冲介导法能有效地转移外源染色体,供体核有促进个体发育的能力。为人工干与鱼类染色体组的组成,进一步研究鱼类个体发育对染色体倍性的依赖关系以及体细胞遗传提供了一条新途径。 相似文献
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河南花背蟾蜍的核型、C-带和Ag-NORs研究 总被引:5,自引:0,他引:5
利用骨髓细胞蒸汽固定法制备染色体标本,研究了分布于河南新乡的花背蟾蜍(Bufo raddei)的核型、C-带和Ag-NORs。结果表明:河南产花背蟾蜍体细胞染色体数为22条,核型公式为2n=22(20m 2sm),全部为中部或亚中部着丝点染色体,NF=44。Ag-NORs具有多态现象。C-带核型显示22条染色体的着丝点均正染,No.1染色体近着丝粒处有不恒定插入型C-带,No.4染色体具有恒定近端部插入型C-带,随体部位被正染的仅占所观察细胞的15%。 相似文献
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我国目前已知有12种蟾蜍,其中以中华大蟾蜍(Bufo gargarizans)和花背蟾蜍(Bufo racldei)最为常见。这两种蟾蜍数量多、分布广、食性杂、食量大,能消灭大量的农林害虫,其耳后腺分泌物蟾酥可入药,是一 相似文献
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对中华大蟾蜍 Bufo gargarizans和花背蟾蜍B. raddei 第36期蝌蚪外形和口部形态结构进行详细观察和描述,并进行了定量比较和分析.中华大蟾蜍蝌蚪体背观呈长卵圆形,全身黑褐色;尾呈桨形,背腹鳍透明无斑;唇齿式为2(2)/3 (即Ⅰ:1+1/Ⅲ).花背蟾蜍蝌蚪体背观呈卵圆形,体背面和侧面为灰黑色或深灰色,腹面灰色有金属光泽;尾呈纺锤形,背鳍近透明,其上有黑色细纹,腹鳍透明无色;唇齿式为2(2)/3(即Ⅰ:1+1/Ⅲ),个别为2(2)/3(1)(即Ⅰ:1+1/1+1:Ⅱ).两种蟾蜍蝌蚪在体色、体型、尾色、尾型、口盘形态结构以及繁殖等方面有着明显区别.对辽宁和华西产的中华蟾蜍蝌蚪的分析表明两地蝌蚪在形态特征方面基本相同,显示出蝌蚪在种内的稳定性.编制了两种蟾蜍蝌蚪的简明检索表,供野外调查和监测参考. 相似文献
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SHINJI KOMAZAKI 《Development, growth & differentiation》1983,25(2):181-192
The cell morphology, cell-to-cell contact behavior and extracellular matrix (ECM) of inner cells (prospective endodermal cells) of newt ( Cynops pyrrhogaster ) embryos were examined from the morula to gastrula stage by light and electron microscopy. The inner cells showed increased cell-to-cell contact from the early blastula to early gastrula stage. The cells formed blebs (5–15 μm in diameter) during the blastula stage, and started to form filopodia and lamellipodia before gastrulation. Alcian blue and lanthanum nitrate treatment revealed ECM components on the cell surface in the early blastula stage and these components increased in amount from the late blastula to early gastrula stage. It is suggested that the increase in ECM components on the cell surface may have some relation with changes in cell-to-cell contact and formation of processes on the cell surface. Besides the cell surface ECM components, glycogen-like granules were observed in intercellular spaces. From the distribution of granules in gastrulae, it is suggested that these may be important in maintaining intercellular spaces for migration of invaginating cells. 相似文献
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KIYOKO YAMAZAKI YAMAMOTO KIMIE YAMAZAKI YOSHIHIRO KATO 《Development, growth & differentiation》1980,22(2):79-92
The karyotype of Cynops pyrrhogaster was determined on the mitotic chromosomes in the presumptive neural area of an early gastrula. 24 chromosomes of a diploid set consisted of 8 metacentric and 4 submetacentric pairs. Individual chromosomes were identified on the basis of their morphology and characteristic C-binding patterns. Sex chromosomes were not identified. Total length of the haploid chromosome set in the presumptive neural area decreased remarkably from morulae to gastrulae, further continued to decrease up to neurulae and thereafter remained unchanged till tail-buds. Chromosome shortening occurring from morulae to gastrulae was accompanied with a prominent decrease in chromosome volume, keeping chromosome width constant. Shortening took place evenly along the longitudinal axis of a chromosome. When gastrulae and neurulae were compared concerning their positions of the appearance of the C-bands, the basic pattern remained unchanged. In certain chromosomes, the number of C-bands decreased as the result of their fusion, as gastrulae proceeded to neurulae. 相似文献
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DIFFERENTIATION OF THE JUNCTIONAL COMPLEX OF SURFACE CELLS IN THE DEVELOPING FUNDULUS BLASTODERM 总被引:11,自引:11,他引:0
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The structure of the junctional complex between surface cells was investigated in blastula, mid gastrula, late gastrula, and early embryo of the teleost fish Fundulus heteroclitus. In blastulae, the intercellular complex is simple and consists of an apical region where the adjacent membranes are closely apposed (40–60 A) and in places touch, an intermediate zone with a wider intercellular space (> 100 A), and incipient desmosomes. In gastrulae, there are frequent points of fusion of membranes along the apical zone of the complex. Dilatations and an increased number of desmosomes in different stages of development are found along the intermediate zone. In mid gastrula, a close or gap junction with an intercellular space of 20 A occurs below the level of the desmosomes. In late gastrula, the gap junction is reduced in extent and desmosomes are better developed. In the early embryo, the basic organization of the complex is the same, although the deeply situated close junctions are no longer apparent and desmosomes and their associated system of filaments are well developed. At this time, the junctional complex is comparable to that of many epithelia and consists of an apical zonula occludens, a short zonula adherens, and deeply situated maculae adherentes. 相似文献
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The patterns of secretion utilized by embryonic cells during early development in the starfish Pisaster ochraceus were studied by transmission electron microscopy and morphometry. In addition to exocytosis of cortical granules, exocytosis and micro-apocrine secretion-like blebbing were performed by secretory vacuoles and secretory vesicles. In 2-cell and 4-cell embryos, as well the 22-hour blastula, secretory vacuole exocytosis (VAE) was the most frequent of the secretory types. In the early to middle gastrula, VAE declined and secretory vacuole blebbing (VAB) appeared. Both VAE and VAB almost disappeared in 5-day gastrulae, and secretory vesicle exocytosis (VEE) as well as the secretory vesicle blebbing (VEB) became dominant. VEB was the only mechanism of secretion in bipinnaria. With regard to yolk granules, Y1, Y2, and Y3 granules underwent lysosome-induced utilization (LIU). In addition, Y3 yolk underwent lysosome-induced sparseness (LIS), followed by Y3-Y5B, the pathway that assumes the formation of Y4 and Y5 intermediate yolk patterns and is completed by the blebbing of Y5 granules in the early to middle gastrulae and 5-day gastrulae. These findings demonstrated the high complexity of the embryonic secretion machinery in sea stars. 相似文献
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本实验第一部分对鳙鱼卵及胚胎在不同的发育时期蛋白质合成的速度进行了研究,实验采用微量克氏定氮法,对鳙卵从未受精卵到受精卵、尾芽期和出膜期,共测定了十三个不同的发育时期。实验结果表明了在鱼的不同胚胎发育时期蛋白质合成速度有着明显的差异。 实验的第二部分对鳙鱼胚胎发育过程氨基酸组成和氨基酸含量进行了测定,其结果显示出鳙鱼卵和胚胎的各发育时期氨基酸的组分十分相似,但氨基酸的含量在各个时期是有差异的。 相似文献
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S Komazaki 《The Journal of experimental zoology》1992,263(4):414-422
Epibolic extension of the presumptive ectodermal layer (PEL) was investigated in embryos of the newt Cynops pyrrhogaster before and during gastrulation. The PEL was composed of only one layer of columnar cells at all stages examined. The cells of the PEL became elongated from the blastula to the early gastrula stage. They were most elongated at the early gastrula stage and then shortened during gastrulation. Present observations suggest that changes in cell shape of the PEL play an important role in the control of the epibolic extension of the newt embryos. The morphology and movement of the isolated cells from the PEL were examined in an attempt to elucidate the role of cell movement in epibolic extension of the PEL. Blebbing and vermiform cells which showed active cell movement appeared at the early blastula stage. The blebbing cells, which formed large hyaline blebs that moved around the circumference of each cell, appeared in large numbers at the early blastula stage. The frequency of the blebbing cells decreased from the early blastula to the early gastrula stage and increased again during gastrulation. The vermiform cells, which had an elongated cell body and moved in a worm-like manner, increased in frequency from the early blastula to the early gastrula stage. The relative number of such vermiform cells was maximal at the early gastrula stage and decreased abruptly during gastrulation. These results suggest that the elongation of the cells of the PEL is controlled by the active cell movement which resembles that of a worm. 相似文献
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Cytoplasmic preparations obtained from late blastulae and early gastrulae of normal R. pipiens eggs contain factors which induce delayed lethal effects when injected into normal eggs at the beginning of cleavage. The same preparations can rescue some defective eggs which occur spontaneously (NS eggs), or are produced experimentally (ES eggs), by relieving the specific developmental syndrome displayed by either type of egg. The syndrome involves abnormal endoderm in which cytolysis is time-programmed. The lethal factors as well as the rescue factors are absent in the normal egg cytoplasm prior to the late blastula stage. 相似文献
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Stability of alpha-fetoprotein messenger RNA in mouse yolk sac 总被引:5,自引:0,他引:5
Changes in the activity of DNA polymerase-α and in subcellular distribution were studied during gastrulation of the sea urchin, Hemicentrotus pulcherrimus. Although the activity of DNA polymerase-α for each embryo was constant up to the blastula stage as reported previously, the enzyme activity increased during gastrulation by about twofold prior to an increase in its DNA content. Thereafter the enzyme activity remained constant at a high level until the early pluteus stage. During gastrulation, an increase in the fraction of DNA polymerase-α was associated with the rough endoplasmic reticulum. During the period between the gastrula and pluteus stages, the cytoplasmic DNA polymerase-α activity decreased gradually with a concomitant increase of activity in the nucleus fraction. The timing of this increase in the nucleus coincided with the increase of DNA content per embryo. These results suggest that DNA polymerase-α accumulates on the rough endoplasmic reticulum during gastrulation and then translocates to the nucleus for DNA synthesis as seen before the blastula stage. DNA polymerase-α obtained from gastrula nuclei did not associate with the endoplasmic reticulum from gastrulae. DNA polymerase-α obtained from the gastrula endoplasmic reticulum membranes became bound to the salt-washed membranes from gastrulae but not to those from unfertilized eggs. Likewise, DNA polymerase-α from the rough endoplasmic reticulum of unfertilized eggs became attached to salt-washed membranes from unfertilized eggs, but not to those from gastrulae. This suggests that DNA polymerase-α is synthesized anew, and a transition of both DNA polymerase-α and endoplasmic reticulum occurs at the gastrula stage. 相似文献
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As "the threshold gears are peculiar to all processes which are flowing past in the world", the problem of looking up of quantitative criterion determining transition of a biological system from one condition to another, is one of the main problems of natural sciences. For analysis of the given problem we investigated some stages of forwardness of marine aster Asterias rubens (mean and late blastula, early and late gastrula, early larva), dis- tinguishing among themselves by morphological characters. Change of structure of cell populations at each stage of development A. rubens analyzed with the help of method of quantitative assessment of functional condition of cells genome. The method is based on cytophotometryc analysis of cell populations coloured by Feulgen (quantifying of DNA in cell) and Naftol yellow S (quantifying of histones in a cell). As the criterion of estimation of functional condition of the cell was used the parameter CFAGEN, coefficient of functional activity of cell genome deduced from histone/DNA ratio after estimation of the absorbency of the nucleus coloured by two chromophores. The data obtained showed that at the moment of organism transition from one stage of development (late blastula) to another (early gastrula) the difference in CFAGEN values between these stages was statistically authentic. Thus comparison of cell distribution histograms has show that cell population conforming to the early gastrula contains 33 % cells with the level of genome functional activity that differs from this one in the cell population conforming to the late blastula. Just in the same moment, the transition of an organism from the stage of late gastrula to the stage of larva is accompanied by statistically authentic distinction in CFAGEN between these stages and availability of more than 1/3 cells (34 %) of the population at the larva stage showing genome functional activity different from that at the late gastrula stage. Thus, it is established, that the biological system passes to qualitatively new condition, if quantity of members of this system changes (increaser or decreases comparatively to a standard point of reference: the norm, previous system status and etc.) not less than on 1/3. 相似文献