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1.
Hemoglobins A and A2 in New World primates: comparative variation and its evolutionary implications 总被引：3，自引：0，他引：3
S H Boyer E F Crosby T F Thurmon A N Noyes G F Fuller S E Leslie M K Shepard C N Herndon 《Science (New York, N.Y.)》1969,166(911):1428-1431
Hemoglobin A(2) (alpha(2)delta(2)) in New World primates represents about 1/160 to 1/16 of total hemoglobin and, by virtue of this low proportion, is presumed to be functionally unimportant. Nonetheless, A(2) exhibits genetic polymorphism by electrophoresis in three out of five genera, whereas the major component, hemoglobin A (alpha(2)beta(2)), is electrophoretically invariant. Moreover, in four genera, including man, the evolutionary accumulation of mutations has been greater in delta than in beta Such findings suggest that both polymorphism and evolutionary changes can accrue to an effectively functionless and thus selectively nearly netutral gene. 相似文献
2.
甘肃滩羊血红蛋白(Hb)及红细胞蛋白质(Ep)多态性的研究 总被引：6，自引：3，他引：3
运用聚丙烯酰胺凝胶电泳技术(PAGE)对甘肃滩羊产区皋兰、景泰及靖远3县285只滩羊的血红蛋白(Hb)基因座、红细胞蛋白质-1(Ep-1)和红细胞蛋白质-2(Ep-2)基因座多态性进行了检测,结果发现甘肃滩羊Hb基因座存在3种基因型HbAA、HbAB、HbBB,它们受HbA和HbB两个共显性等位基因控制,其中HbB和HbBB在3个群体中均占优势;本研究未在Ep-1和Ep-2基因座上检测到多态性,它们均呈现单态。 相似文献
3.
A new variant of the normal minor component Hb A(2) has been detected in a family that lives in Sphakiá, Crete. Chemical studies of this abnormal hemoglobin, designated Hb A(2) delta Sphakiá, indicates a substitution of the histidyl residue number two of the delta-chain by an arginyl residue. 相似文献
4.
Hemoglobin switching in sheep and goats: occurrence of hemoglobins A and C in the same red cell 总被引：2，自引：0，他引：2
Sheep and goats switch from the synthesis of hemoglobin A (alpha(2)beta(2)(A)) to hemoglobin C (alpha(2)beta(2)(C)) when made anemic. We have demonstrated the existence of the asymmetrical hybrid hemoglobin, alpha(2)beta(A)beta(C), in the circulating red cells of anemic sheep. These erythroid cells, therefore, synthesized both A and C hemoglobin simultaneously. Thus, the switch appears to be mediated by selective gene expression rather than by a clonal or cellular selective mechanism. 相似文献
5.
Kaeberlein M Steffen KK Hu D Dang N Kerr EO Tsuchiya M Fields S Kennedy BK 《Science (New York, N.Y.)》2006,312(5778):1312; author reply 1312
Calorie restriction (CR) increases life span in yeast independently of Sir2. Lamming et al. (Reports, 16 September 2005, p. 1861) recently proposed that Sir2-independent life-span extension by CR is mediated by the Sir2 paralogs Hst1 and Hst2. Contradictory to this, we find that CR greatly increases life span in cells lacking Sir2, Hst1, and Hst2, which suggests that CR is not mediated by Sir2, Hst2, or Hst1. 相似文献
6.
A new hemoglobin (Hb), Portland 1, has been found in a newborn infant having multiple congenital anomalies and complex autosomal chromosomal mosaicism. The new hemoglobin has a unique tetrameric structure (molecular weight, 66,000) composed of two pairs of different types of chains, neither of which is alpha, gamma(2)x(2). The x-chain of Hb Portland 1 may be a new type of hemoglobin chain, but the available evidence suggests that it may be identical with the epsilon chain. We suggest that Hb Portland 1 is an embryonic hemoglobin that persisted until after birth in relatively large amounts in this patient. 相似文献
7.
为了提高毕赤酵母(Pichia pastoris)中重组植酸酶的表达,在来源于Pichia stipitis的低氧诱导启动子PsADH2控制下,进行了透明颤菌血红蛋 相似文献
8.
中药“球康”对雏鸡感染柔嫩艾美尔球虫部分血液理化指标的影响 总被引：1，自引：0，他引：1
[目的]为鸡球虫病的有效防治提供参考。[方法]将雏鸡随机分为感染球虫对照组（Ⅰ）、感染球虫给中药＂球康＂组（Ⅱ）和不感染不给药对照组（Ⅲ）,Ⅰ、Ⅱ组鸡接种柔嫩艾美尔球虫孢子化卵囊,于感染当天在Ⅱ组鸡饲料中添加2%中药＂球康＂微粉制剂,测定雏鸡接种球虫0、5、8 d时红细胞数量（RBC）、白细胞数量（WBC）、红细胞压积（HCT）、血红蛋白浓度（HGB）及血清K＋、Na＋、Cl-、Ca2＋、P3＋浓度和TP含量。[结果]与Ⅲ组相比,接种球虫第5天,Ⅰ、Ⅱ组鸡RBC总数、HGB含量和HCT均出现下降趋势;接种球虫第5天,Ⅰ、Ⅱ组雏鸡血清K＋显著升高,第8天有所降低;接种球虫第8天,各组血清Na＋比接种第5天略有下降,Ⅰ、Ⅱ组雏鸡血清Ca2＋升高;接种球虫第5天,Ⅰ、Ⅱ组雏鸡血清Cl-和P3＋略有降低;接种球虫后,Ⅰ、Ⅱ组雏鸡血清TP含量降低。Ⅱ组雏鸡仅血清K＋浓度显著高于Ⅲ组（第5天）,血清Na＋、Cl-、Ca2＋、P3＋浓度和TP含量升高或降低程度与Ⅲ组无显著性差异。[结论]中药＂球康＂通过抵抗球虫感染,在一定程度上有助于维持血液理化指标的恒定。 相似文献
9.
Vossmeyer T Reck G Katsikas L Haupt ET Schulz B Weller H 《Science (New York, N.Y.)》1995,267(5203):1476-1479
A simple preparation of Cd(17)S(4)(SCH(2)CH(2)OH)(26) clusters in aqueous solution leads to the formation of colorless blocky crystals. X-ray structure determinations revealed a superlattice framework built up of covalently linked clusters. This superlattice is best described as two enlarged and interlaced diamond or zinc blende lattices. Because both the superlattice and the clusters display the same structural features, the crystal structure resembles the self-similarities known from fractal geometry. The optical spectrum of the cluster solution displays a sharp transition around 290 nanometers with a large absorption coefficient ( approximately 84,000 per molar per centimeter). 相似文献
10.
Hemoglobin Freiburg: abnormal hemoglobin due to deletion of a single amino acid residue 总被引：5，自引：0，他引：5
R T Jones B Brimhall T H Huisman E Kleihauer K Betke 《Science (New York, N.Y.)》1966,154(752):1024-1027
Structural characterization of a new variant of human hemoglobin (adult), designated hemoglobin Freiburg, indicates the deletion of the valyl residue No. 23 from an otherwise normal beta-chain. The formula may be written (alpha2)beta(2)(23val-0). The abnormal hemoglobin is present with hemoglobin A in the proposita and in two of her three living children, but is not detectable in her parents. We postulate that this variant represents a triplet base deletion which most likely resulted from an unequal crossing-over between two normal betachain loci during meiosis in one of the parents of the proposita. 相似文献
11.
In vivo studies of the biosynthesis of chick hemoglobins 1 and 2 showed an over-all higher incorporation of glycine-2-C(14), valine-4-C(14), valine-1-C(14), leucine-G-C(14), and histidine-(2-ring)-C(14) in hemoglobin 2; in vitro studies made with intact nucleated chick erythrocytes showed the higher incorporation of glycine-2-C(14), valine-1-C(14), and histidine-(2-ring)-C(14) in hemoglobin 1. Hybridization of chick hemoglobins produced an electrophoretically distinguishable new component. 相似文献
12.
家蚕第2肾形卵（ki—2）的连锁分析 总被引：1，自引：0，他引：1
以实验遗传学方法对家蚕第２肾形卵（ｋｉ－２）基因进行了连锁分析。结果发现,ｋｉ－２基因与第１９连锁群的狭胸（ｎｂ：１９－３１．２）基因连锁。以此确定Ｋｉ－２基因与第１９染色体上。 相似文献
13.
Oxygen binding in cyanmet hybrid and normal hemoglobins: applicability of sequential and two-state concerted models 总被引：1，自引：0，他引：1
A P Minton 《Science (New York, N.Y.)》1974,184(136):577-579
The cyanmet hybrid hemoglobins alpha(2)beta(+CN)(2) and alpha(+CN)(2)beta(2) are widely held to be similar or equivalent in structure and subunit interactions to the partially oxygen-liganded species alpha(2)(beta * O(2))(2) and (alpha * O(2))(2)beta(2), respectively. An analysis of precise data on oxygen binding to the cyanmet hybrids and normal hemoglobin shows that if this is the case, then cooperative ligand binding in hemoglobin is more properly described by some model of the sequential type than by any twostate concerted model. 相似文献
14.
After administration of glycine-2-(14)C to a patient with thalassemia, the specific activities of heme and globin of F hemoglobin were consistently higher than those of hemoglobin A. After reaching a maximum, the ratio of the specific activity of heme to that of globin remained constant within each hemoglobin. Explanations considered include dilution by preformed subunits, differential turnover of hemoglobins, and possibly more than one heme-synthesizing pool. 相似文献
15.
四川水牛血液蛋白多态性研究 总被引：2，自引：1，他引：1
采用聚丙烯酰胺凝胶电泳和醋酸纤维素薄膜电泳对四川水牛不同地方类群的血清运铁蛋白及血红蛋白多态性进行检测。并对血红蛋白电泳区带扫描定量,发现存在量的多态性。血红蛋白有AA、AB、BB三种基因型,受Hb~A、Hb~B等显性等位基因控制,基因频率分别为0.048、0.952。血清运铁蛋白有AA、AD、DD三种基因型,受Tf~A、Tf~D等显性等位基因控制,基因频率分别为0.296、0.704。 相似文献
16.
枯草芽孢杆菌B_1、B_2液对“黄河蜜”瓜采后黑斑病和粉霉病的抑制效果 总被引：5，自引：3，他引：5
研究了枯草芽孢杆菌B1、B2的活菌液、代谢液对“黄河蜜”甜瓜采后黑斑病和粉霉病的抑制效果。离体条件下,B1、B2活菌液对黑斑病菌(A.alternata) 的抑制率分别达到100 %和94 %,而对粉霉病菌(T.roseum)的抑制率均达到100 %。离体条件下,B1、B2活菌液均能显著抑制“黄河蜜”甜瓜采后黑斑病和粉霉病的侵染和扩展。B1、B2代谢液显著抑制粉霉病的扩展,但对黑斑病的扩展无抑制效果。 相似文献
17.
A striking similarity has been found between the composition of peptides obtained from tryptic digestion of normal adult hemoglobin (hemoglobin A) and fetal hemoglobin (hemoglobin F). 相似文献
18.
Selman C Lingard S Gems D Partridge L Withers DJ 《Science (New York, N.Y.)》2008,320(5879):1012; author reply 1012
Taguchi et al. (Reports, 20 July 2007, p. 369) reported that mice heterozygous for a null mutation in insulin receptor substrate-2 (Irs2) display a 17% increase in median life span. However, using the same mouse model, we find no evidence for life-span extension and suggest that the findings of Taguchi et al. were due to atypical life-span profiles in their study animals. 相似文献
19.
云南家禽十项生理常值的测定 总被引：6，自引：0，他引：6
我们进行了云南武定鸡、火鸡、云南鸭、番鸭(瘤头鸭)、云南鸽和鹌鹑等七种家禽的体温、心率、呼吸频率、红细胞沉降速度(血沉)、血红蛋白、红细胞计数、白细胞计数、嗜酸性白细胞计数、血小板计数、白细胞分类计数等十项生理常值的测定。结果表明:云南武定鸡的呼吸频率(28.84次/min)和血红蛋白(102.4g/L)比广东三黄鸡的(19.4次/min)和(74.09g/L)快(高):火鸡的血红蛋白(136.6g/L)比文献报道的值(88～134g/L)高;云南鹅的心率(109.47次/min)和白细胞分类计数中的假嗜酸性白细胞(异嗜性粒细胞)的比例(36.23%)比文献报道的值(300次/min)和(50%)低:云南鸭的心率(102.34次/min)呼吸频率(19.59次/min)和血红蛋白(110.3g/L)比文献报道的值(178次/min)、(42次/min)和(127g/L)低,云南鸽的呼吸频率(56.64次/min)比文献报道的值(30次/min)高,而白细胞数(38.9×109/L)比文献报道的值(13.0×109/L)高。 相似文献
20.
以新鲜牦牛血为原料,采用超声波破碎进行溶血,利用羧甲基纤维素(CMC)的吸附作用提取血红素.结果表明:提取牦牛血红素的最佳的条件为:10mL红血球中,去离子水添加量为40mL,超声波破碎时间为20min,分离pH值为2.0,CMC-Na(3%)的添加量为3mL,该工艺从牦牛血全血中提取的血红素产率为3.028mg/mL. 相似文献