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血红蛋白G-Coushatta (HbG-Coushatta)是
一种慢速异常血红蛋白。它的Is链N端第22位
谷氨酸被丙氨酸替代,即尸,Glu-Alao首先由
Schneide:等在美国中西部印第安人中发现[[71。最
近我们在湖北省黄陕县的一个汉族家庭中发现
两名同胞姐妹为Hb G-Coushatta纯合子,并首
次应用DABITC/PITC双偶合顺序测定法鉴定
了此种异常血红蛋白的化学结构,现报道如下。 相似文献
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Summary A 22-year-old man and his father, both with 47 chromosomes, an extra small metacentric chromosome and the presumptive karyotype of 47,XY, ?Yq-, are presented.Literature concerning cases with 47 chromosomes and a small metacentric chromosome is reviewed and discussed. It is concluded that it is unlikely that persons with 47 chromosomes and an extra small metacentric chromosome constitute a new cytogenetic disease the syndrome of the metacentric microchromosome, as suggested by Abbo and Zellweger (1970).Persons with 47 chromosomes and an extra small metacentric chromosome have most probably a great variety of chromosomal aberrations, some of autosomal and some of sex chromosomal origin.
Zusammenfassung Es wird über einen 22jährigen Mann und seinen Vater berichtet. Beide hatten 47 Chromosomen: Ein zusätzliches metazentrisches kleines Chromosom und den angenommenen Karyotyp 47,XY, ?Yq-.In diesem Zusammenhang wird die Literatur über Fälle mit 47 Chromosomen und einem kleinen metazentrischen Extrachromosom diskutiert. Die Autoren gelangen zu der Schlußfolgerung, es sei unwahrscheinlich, daß eine neue cytogenetisch charakterisierte Krankheit, das Syndrom des metazentrischen Mikrochromosoms, wie Abbo u. Zellweger (1970) es annehmen, in der Tat existiert. Personen mit 47 Chromosomen und einem kleinen metazentrischen Extrachromosom haben sehr wahrscheinlich eine große Anzahl verschiedener Chromosomenaberrationen, einige autosomalen und andere geschlechtschromosomalen Ursprungs.相似文献
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XY性染色体决定系统是决定植物性别的主要方式,但是对于其起源与演化机制却知之甚少。目前认为,携带控制雌蕊或雄蕊发育基因的一对常染色体由于某种未知原因的突变形成早期的neo-Y或neo-X性染色体,随着演化的进行,早期XY性染色体之间的重组逐渐受到抑制,非重组区域扩展最终形成异型的性染色体。研究发现,重复序列的累积以及DNA甲基化等因素都可能参与了XY性染色体的异染色质化、重组抑制及Y染色体体积增大过程。转座子作为一种基因组中含量最高的重复序列在性染色体演化中扮演了重要的角色,包括性染色体演化的起始激发,以及导致性染色体局部表观遗传修饰使其发生异染色质化扩展和重组抑制。文章综述了转座子在植物性染色体上的累积及其与性染色体异染色质化之间的关系,并简要分析了转座子在性染色体演化过程中的作用。 相似文献
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花背蟾蜍XY型性别决定的细胞遗传学证据 总被引:3,自引:0,他引:3
花背蟾蜍的性别决定,可能与第6对染色体相关,其类型为XY型。作者以体外不同步转化的淋巴细胞为对象,采用BrdU-Hoechst-Giemsa技术,观察了花背蟾蜍的染色体复制过程。发现第6对染色体的长臂近心端处是SRR区域。又因为在雌性个体中两个SRR区域是同步复制的,而在雄性个体中是不同步复制的,所以在分裂中期的染色体上出现了异态现象。依此,作者确定花背蟾蜍的性染色体构成是XY型。 相似文献
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从XY雌鱼雌核发育产生YY超雄黄颡鱼 总被引:9,自引:0,他引:9
采用激素性逆转结合雌核发育技术,从XY雌鱼产生YY超雄黄颡鱼。与性逆转和后代测交选种技术比较,本文的方法可以缩短两代的育种时间,并提高超雄鱼的产出。通过测交证明,与正常的XY雄鱼一样,YY超雄黄颡鱼是能成活和有生育力的,其后代雄鱼占75.9%—100%,平均90.30%。从29尾雌鱼产生的雌核发育的后代294尾,只有11尾雄鱼,绝大多数是雌鱼;而在12尾YY超雄鱼测交的后代出现0—24.1%雌鱼。从上述结果可以推测,黄颡鱼的性决定体制是雌性配子同型(XX♀/XY♂),但常染色体性修饰基因的影响是比较明显的。本文还对超雄鱼在商业上大量生产全雄黄颡鱼的可行性和应用前景进行简要的讨论。 相似文献
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46,XY女性患者SRY基因启动子区域的突变分析 总被引:1,自引:0,他引:1
大约15%的46,XY女性患者中发现SRY基因编码区突变,其他患者可能是SRY基因的调节区, 包括启动子区域发生了突变,或者其他相关基因发生突变所致。本文采用限制性酶切、PCR-SSCP及银染检测技术,对7例患者SRY基因的启动子区域进行了突变筛查, 结果未发现异常,提示这些患者的病因与SRY基因启动子区域本身无关,结合对患者SRY基因HMG基序DNA的突变分析结果,表明除SRY基因异常外还存在其他导致46,XY女性性反转综合征的遗传机制。
Abstract:Using restriction endonuelease digestion and PCR-SSCP with silver staining,we analyzed the promotor region of SRY gene in seven 46,XY femalcs.The results showed no abnormality,thus ruling out the mutations in the promotor region of the SRY gene as a possible cause of sex reversal in these XY females.In view with the absence of the mutations in the HMG regions of the SRY genes of several patients,it is suggested that SRY gene is not the only gene responsible for testicular development but is one of many hierarchical genes involved in a genetic cascade for sexual differentiation. 相似文献
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菌体的分泌蛋白质在宿主和菌体的相互作用之间起着重要的作用. 本研究采用双向凝胶电泳的方法建立了长双歧杆菌XY01分泌蛋白质图谱,通过MALDI-TOF/TOF质 谱鉴定和数据库搜索,对鉴定到的分泌蛋白进行了分析. 共检测到21个蛋白质点, 成功鉴定18个蛋白质点,分别代表14个不同的蛋白质,等电点分布在4.5~7.0之间 ,分子质量分布在20 ~65 kD之间;通过COGs分类和功能分析,信号肽和细胞定位及KEGG代谢通路分析. 结果表明,这些蛋白质对菌体细胞壁/膜的形成、生物信号传导和物质代谢等起着重要作用. 研究结果为长双歧杆菌蛋白质组学和基因组学的研究提供了参考. 相似文献
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Male-specific antigen expression by XY teratocarcinomas PCC7 and 7 is demonstrated first by the rejection of tumors by female but not by male mice following challenge with these cell lines. Male-specific antigen expression is confirmed by an indirect method in which females are immunized against H-Y antigen by male skin grafts. A variant of PCC7 lacking male-specific antigen expression is described. Analysis of the karyotype and of the DNA from this variant indicate that the loss of male-specific antigen expression is a result of the loss of the Y chromosome. The ability to recover variants that have lost expression of male-specific antigen opens the possibility of their selection after mutagenesis.Aspects of this work have been presented at the 10th Cold Spring Harbor Conference on Cell Proliferation, September 1982 相似文献
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The cooperativity between hydrogen and halogen bonds in XY···HNC···XY (X, Y = F, Cl, Br) complexes was studied at the MP2/aug-cc-pVTZ
level. Two hydrogen-bonded dimers, five hydrogen-bonded dimers, and ten trimers were obtained. The hydrogen- and halogen-bonded
interaction energies in the trimers were larger than those in the dimers, indicating that both the hydrogen bonding interaction
and the halogen bonding interaction are enhanced. The binary halogen bonding interaction plays the most important role in
the ternary system. The hydrogen donor molecule influences the magnitude of the halogen bonding interaction much more than
the hydrogen bonding interaction in the trimers with respect to the dimers. Our calculations are consistent with the conclusion
that the stronger noncovalent interaction has a bigger effect on the weaker one. The variation in the vibrational frequency
in the HNC molecule was considered. The NH antisymmetry vibration frequency has a blue shift, whereas the symmetry vibration
frequency has a red shift. A dipole moment enhancement is observed upon formation of the trimers. The variation in topological
properties at bond critical points was obtained using the atoms in molecules method, and was consistent with the results of
the interaction energy analysis. 相似文献
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考察4种无机铁盐改性沸石对丁醇生产菌Clostridium acetobutylicum XY16的固定效率及其发酵产丁醇性能的影响。结果表明:铁改性沸石对菌体的固定效率均优于未改性沸石,而Fe3+改性效果优于Fe2+,经FeCl3改性的沸石对菌体具有良好的吸附作用,当Fe3+-zeolite用量为180 g/L时,细胞的固定效率达到87%。在此基础上,比较了沸石负载的铁离子量对丁醇发酵性能的影响,沸石负载的铁离子量为6.0 mg/g时可显著提高丁醇发酵性能,当葡萄糖质量浓度为60 g/L时进行发酵,丁醇产量为13.5 g/L,总溶剂可达20 g/L,总溶剂的生产速率为0.385g/(L.h),比游离细胞发酵分别提高了9.5%、10.3%和40%。 相似文献
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Under what circumstances is the human XY bivalent tangled? A note on chromosomally-derived sterility 总被引:1,自引:0,他引:1
A Rosenmann J Wahrman C Richler I Madgar R Weissenberg R Chaki 《Cytogenetics and cell genetics》1987,45(1):58-61
A microspread, early-mid diplotene nucleus of a man with a normal karyotype and presumably normal meiosis is compared with a similar, earlier described nucleus of a man with meiotic arrest, heterozygous for a (14;21) Robertsonian translocation (Rosenmann et al., 1985). The axes of the XY bivalent of normal diplotene have an extremely tangled configuration, whereas those of the meiotically-arrested cell are straight, recalling the shape of the XY which is normally found in early pachytene. The morphological reversal from the complex configuration to a simpler shape may be associated with reactivation of the sex chromosome(s). Such a reactivation may be responsible for the sterility of the carrier of the Robertsonian translocation which thus may be considered as chromosomally-derived. The diplotene cells shown here have autosomal bivalents with continuous axes and various degrees of focal separation as is typical for diplotene in general. The observations on axis continuity, bivalent segmental dilatations, and XY tanglement in diplotene are compared with findings by others in human ultrathin sectioned material. 相似文献