共查询到20条相似文献,搜索用时 15 毫秒
1.
Zhang Lifan Liu Chong Lian Linsheng Zhao Chunjiang Bao Haigang Wu Changxin 《自然科学进展(英文版)》2007,17(12):1419-1424
Globin protein family plays an important role in storing and transporting oxygen. As a newly reported globin, the revealed function of neuroglobin includes binding and storing oxygen as well as facilitating the utilization of oxygen in neuronal cells. In the present study, mutations in exons of chicken Ngb gene were identified with the method of sequencing and created restriction site PCR in Tibet chicken and other four lowland chicken breeds. The mutations of Lys-2224(E4)-Asn and Ser-2279(E4)-Gly were identified in exon 4 of the gene. The Lys-2224(E4)-Asn mutation existed only in Tibet chicken and the mutation frequencies increased with increasing altitude. Analysis of the haplotype and diplotype of the two mutations in Tibet chicken populations of different altitudes showed that the frequencies of TG haplotype and TTGG diplotype also increased with increasing altitude, while the reverse tendency was found on GGAA diplotype. Under the hypoxic simulation incubation, the main haplotype was TG in living embryos and GA in dead embryos. The results showed that the Lys-2224(E4)-Asn mutation may be a specific mutation associated with hypoxia adaptation in Tibet chicken. 相似文献
2.
变异率和种群数目自适应的遗传算法 总被引:7,自引:0,他引:7
提出了针对个体变异率和种群数目的2种自适应方法.算法中个体变异率根据其适度值在种群中的排序自适应调整,使优良个体具有较小的变异率继续进化,而使种群中较差个体具有较大变异率,增强了种群搜索能力.同时根据种群个体适度值方差动态调整变异率曲线,种群数目调整则根据最优个体更新率动态增大,以动态适应解空间的规模避免采样误差造成的进化停滞.通过在不同尺度的NK Landscape上与传统的简单遗传算法(SGA)比较可得,2种自适应方法的引入对遗传算法的寻优能力有了明显改进. 相似文献
3.
TANG Beisha LUO Wei ZHAO Guohua XIAO Jianfeng LI Qi MA Yanlin XIA Kun YANG Qidong 《自然科学进展(英文版)》2003,13(6)
The form of Charcot-Marie-Tooth (CMT) neuropathy that maps to Xql3 is X-linked dominant, or X-linked intermediate. Heterozygous females are more mildly affected than hemizygous males. It has been known that this type of CMT is caused by mutations of connexin32 (Cx32) gene. A typical X-linked recessive Charcot-Marie-Tooth Chinese family was analyzed with single strand conformation polymorphism method. A Cx32 gene point mutation, ArglSGln, in exon 2 was identified in all affected family members, suggesting that this mutation is responsible for the CMT incidence of this family. 相似文献
4.
河口慧海的入藏活动及其对日本藏学的贡献 总被引:3,自引:0,他引:3
河口慧海是日本历史上第一位进入西藏拉萨的日本人,同时也是诸多外国入藏中一位颇具世界性影响的人物。本利用不少第一手史料,对河口慧海的两次进藏活动及其对日本藏学方面的贡献等做了比较详细的考察,这不仅有助于我们对日本藏学发展史的了解,同时也有助于了解近代日本与中国西藏之间的关系史。 相似文献
5.
YANBingxue DENGXuemei FEIJing HUXiaoxiang WUChangxin LINing 《科学通报(英文版)》2003,48(15):1561-1564
In this experiment, F2 chicken derived from Broilers crossing to Silky are used to study the effect of growth hormone gene on growth and carcass traits. The partial gene is amplified by two pairs of primers, and single nucleotide polymorphism (SNPs) is detected by the technique of PCR-RFLP (restriction fragment length polymorphism), and then confirmed by DNA sequencing. The mutations are found in intron 3 and intron 4 respectively, and can be clarified by digestion with EcoRVand Msp I. The results of least square analysis indicate that the gene has significant association with some carcass traits, such as breast muscle weight, breast muscle rate, abdominal fat rate, and has no association with other growth and carcass traits, such as live weight, carcass weight, eviscerated yield with giblet, eviscerated yield, leg muscle weight, heart weight, liver weight, abdominal fat weight, chest angle width, head and neck weight,shank and claw weight, wing weight, muscular stomach weight, glandular stomach weight, ovary or testicular weight, shank girth, small intestine length, 1-week body weight, 6-week body weight, 12-week body weight, etc. These results demonstrate that GH gene could be a genetic locus or linked to a major gene significantly affecting the growth and carcass traits in chicken. 相似文献
6.
针对函数优化问题,提出一种自适应变异遗传算法来提高局部搜索的能力,弥补简单遗传算法易于早熟收敛的缺陷。最后以De Jong函数为仿真对象,将此算法与其它三种遗传算法进行比较,仿真结果表明此算法对于函数优化问题非常有效,大大加快了算法的收敛速度,并大幅度提高了搜寻到最优解的概率。 相似文献
7.
【目的】检测大花序桉群体与环境适应性相关的基因组位点,为种质资源保护和利用提供分子生物学信息。【方法】利用84个SSR标记(包括29个基因组SSR 和55个EST-SSR)分析引种到广西,来源于澳大利亚昆土兰州北部和南部各7个大花序桉群体,通过Mantel 检验确定群体间是否存在地理隔离;检测群体间分化系数(Fst)离群值的受选择位点;并基于空间分析法检测与群体气候因子显著相关的等位片段,将显著相关位点的序列与NCBI数据库比对进行功能注释。【结果】大花序桉北部与南部群体间存在地理隔离,基于19个气候因子的聚类分析将北方与南方群体分为独立的组,这表明气候因子亦驱动了群体的分化。共检测到Fst离群值的受选择SSR位点39个(46.4%),其中,LOSITAN软件检测到12个正向选择位点和17个平衡选择位点。5个Fst离群值位点的6个等位片段与1个或多个气候因子显著相关(P<0.001),其等位频率在北部与南部群体间差异明显,其中,Embra6-118 bp与最冷月最低气温(Tmcm)显著相关,位点DNA序列的功能注释为碱性螺旋-环-螺旋(basic helix-loop-helix, bHLH)转录因子bHLH155;Embra20-121 bp与最暖季度降水量(Pwq)显著相关,位点的功能注释为蔗糖转运蛋白(sucrose transporters);EUCeSSR676-168 bp与Tmcm、Pwq、年均气温(Tma)和最暖月最高气温(Tmwm)均显著相关,位点的功能注释为光系统Ⅱ稳定性/组装因子HCF136 (photosystem II stability/assembly factor HCF136);另外两个显著相关位点EUCeSSR298和EUCeSSR1009的功能未知。【结论】大花序桉北部与南部群体的显著分化受长期气候的影响,在第四纪大冰期可能存在北部和南部避难所。与气候因子显著相关的SSR位点在北部和南部群体间的等位频率差异为基于正向选择的气候适应性提供了分子证据。 相似文献
8.
Shanru Li Dongping Wang Hong Lan Wenyan Zhang Baosheng Ge Jiqing Li Cuie Wang Yifan Lu Yanyan Shi Runfang Li 《科学通报(英文版)》1999,44(13):1207-1207
Gene mapping of a mouse coat mutation has been investigated. First, 100 10-bp random primers were used to amplify DNA, but
the mutation could not be located by this method because there were no correlation between the amplified products and coat
phenotypes. Second, by usingIdh1, Car2, Mup1, Pgb1, Hbb, Es10, Es1, Mod1, Gdc1, Ce2, Es3 as genetic markers, linkage test crosses (two-point test) consisting of intercrossing uncovered BALB/c mice (homozygotes)
to CBA/N and C57BV6 mice with normal hair and backcrossing the heterozygotes of the F1 to the uncovered BALB/c mice were made.
It was soon evident that the mutation was linked toEs3 on chromosome 11. Furthermore, three-point test was made by usingEs3 and D11Mit8 (a microsatellite DNA) as genetic markers. The result showed that the mutation was linked toEs3 with the percentage recombination of (7.89 ± 2.19)%, and linked to Dl1Mit8 with the percentage recombination of (26.30± 3.57)%.
The percentage recombination betweenEs3 and D11Mit8 was (32.90±3.81)%. The mutation was named Uncovered, with the symbolUncv. According to the recombinations, the loci order was D11Mit8-26.30±3.57-Uncv- 7.89 -2.19-Es3. From the location on the chromosome, it was concluded that the mutation was a new mutation which affected the skin and hair
structure of mouse. TheUncv has entered MGD (Mouse Genome Database). 相似文献
9.
张智丹 《长春师范学院学报》2007,(11)
太平洋战争期间,美国对西藏问题采取了维持现状的政策,力图抑制中、英就西藏地位问题的论争,一方面维持盟国间的合作局面,一方面便利于其对西藏地区的渗透。美国对西藏问题的干预扩大了其对西藏局势的影响力,并为战后进一步干预西藏事务做了铺垫。 相似文献
10.
西藏生态环境区划研究 总被引:4,自引:0,他引:4
西藏地域面积广大,各地区的自然和社会经济条件差异十分显著.在计算各县生物生产量(I)和社会经济系统对环境作用强度(S) 的基础上,将西藏自治区划分为6 个生态环境地区,并对各地区的基本状况进行了简要描述 相似文献
11.
西藏三语教学的昨天、今天和明天 总被引:7,自引:0,他引:7
以“三个面向”的精神为指导,改革和发展我区各级各类学校教育的问题,就语文教学角度来讲,也就是要创造条件把我区当前实行的藏汉两语教学或汉英语教学尽快过渡到藏汉英三语教学的问题。但鉴于西藏特殊的人文情况,我们在调查中发现我区的语文教学当前也碰到一些新情况,面临一些新问题。本文试图通过回顾我区语文教学的历史,分析我区语文教学的现状,从中找出一些克服我区实施三语教学困难的对策。 相似文献
12.
目的:对临床诊断为眼皮肤白化病(OCA)患者的TYR基因进行突变筛查,以了解我国大陆OCA患者TYR基因突变类型。方法:应用PCR技术扩增患者及其父母的TYR基因外显子、外显子-内含子交界区及启动子区,以DNA序列测定技术进行突变筛查与鉴定。结果:在8名患者的16个TYR等位基因内,查明9种突变;其中错义突变4种(R77Q、E294K、R299H和W 400L),无义突变2种(R116X和R278X),插入突变2种(929 insC和232 insGGG),剪切位点突变1种(IVS1-3 C>G)。结论:W 400L、R299H分别占本研究所检出全部OCA1突变等位基因的31.3%(5/16)和18.8%(3/16),可能为中国大陆人群中较常见的TYR基因突变类型。 相似文献
13.
张智丹 《长春师范学院学报》2007,26(6):55-58
澶钩娲嬫垬浜夋湡闂?缇庡浗瀵硅タ钘忛棶棰橀噰鍙栦簡缁存寔鐜扮姸鐨勬斂绛?鍔涘浘鎶戝埗涓€佽嫳灏辫タ钘忓湴浣嶉棶棰樼殑璁轰簤,涓€鏂归潰缁存寔鐩熷浗闂寸殑鍚堜綔灞€闈?涓€鏂归潰渚垮埄浜庡叾瀵硅タ钘忓湴鍖虹殑娓楅€?缇庡浗瀵硅タ钘忛棶棰樼殑骞查鎵╁ぇ浜嗗叾瀵硅タ钘忓眬鍔跨殑褰卞搷鍔?骞朵负鎴樺悗杩涗竴姝ュ共棰勮タ钘忎簨鍔″仛浜嗛摵鍨? 相似文献
14.
GUO Yibin PAN Jingxin DU Chuanshu 《科学通报(英文版)》2005,50(21):2534-2536
Mucopolysaccharidosis type Ⅱ is of high genetic heterogeneity. PCR-DNA sequencing was used to study the mutation hot spots in the IDS gene of a Chinese MPS Ⅱ pedigree. A new mutation (1467-A) not yet reported worldwide was detected. This mutation located at 448th codon in the coding region of exon 9 deletes one “A” at the end of 1467 bp (cDNA). The frame-shift mutation makes the peptide chain shorten from amino acids 550 to 459, probably altering the configuration of IDS enzyme protein remarkably and lowering the activation of IDS greatly. Therefore it is supposed to be the direct cause of the patient with MPS Ⅱ and to be a necessary premise for prenatal gene diagnosis. 相似文献
15.
教育改革是随知识经济兴起而出现的一种趋势,是素质教育的核心。民族地区的教育改革是全国教育改革的重点,是提高民族地区教学质量、培育创新人才的关键。文章就如何把教育改革与西藏地区计算机教学相结合进行了探讨。 相似文献
16.
从藏鸡(海拔3000米藏区、自然放养、未使用过抗生素)肠道内筛选乳杆菌, 经16s rDNA和生理生化试验鉴定为植物乳杆菌.通过耐酸耐胆汁试验和肠道黏附试验测试, 表明其具有良好的耐酸耐胆汁能力和肠道黏附能力.为使外源质粒顺利转化入乳杆菌, 进行电场强度的优化, 再按照优化后的电场强度, 将禽冠状病毒pSIP409 N重组质粒电转化入该株乳杆菌, 进行双酶切和PCR鉴定.将经鉴定成功转入的重组乳杆菌, 用诱导肽SppIP诱导表达, 再进行SDS PAGE检测外源蛋白的表达.结果表明N蛋白能够顺利表达. 上述试验证明该株植物乳杆菌具有作为乳酸菌活载体疫苗的潜力. 相似文献
17.
18.
KANG Lianchun* ZHAO Xirong* ZHOU Yongshuang JIA Yixing KANG Suhai CHEN Zhu ZHAO Min CUI Jiantao LI Wenmei SUN Anle & LU Youyong . The Hospital of People Liberation Army Taiyuan China . The School of Oncology of Peking University Beijing Institute for Cancer Research Beijing China Correspondence should be addressed to Lu Youyong * The authors contributed equally to this work. 《科学通报(英文版)》2003,48(4):333-337
Peutz-Jeghers syndrome (PJS) is an autosomal dominant disease that is characterized by multiple gastrointestinal hamartomatous polyps and melanin spots on lips and buccal mucosa at young age[1,2]. Previous studies have demonstrated that PJS predisposes carriers to cancers of gastrointestinal tract, uterus, ovary, testis, breast and other extragastrointestinal organs[3—5]. The STK11 gene, encoding a serine/threonine kinase at chro-mosome 19p13.3, was identified in 1998 as the main causativ… 相似文献
19.
青海省湟源县日月藏族乡藏族ABO血型调查分析 总被引:2,自引:0,他引:2
本文对青海省湟源县日月藏族乡的300名藏族人群进行了ABO血型的随机抽样,其中男女各半,试图了解青海这一藏区的ABO血型分布情况和藏族族源.调查结果为:(1)藏族的ABO血型分布为A型占20.67%、B型占22.33%、O型占48.33%、AB型占8.67%|,特征是:O>B>A>AB,基因频率是p=0.1575、q=0.1673、r=0.6752,特征为r>q>p.(2)藏族ABO血型分布的民族指数为0.9991.此次调查青海省湟源县日月藏族乡的藏族人群具有较高的O基因频率,具有典型的南方人群结构特征,说明藏族与南方诸多民族有着族源关系.调查结果基本上与以往的文献资料相符,且符合我国省区血型频数分布规律. 相似文献
20.
探讨不同低氧训练模式对机体骨骼肌HIF 1α mRNA水平和蛋白水平表达的影响。6周龄SD雄性大鼠120只,经3周适应性训练和力竭实验筛选出90只,随机分成9组:常氧安静对照组、持续低氧安静组、间歇低氧安静组、低住低练耐力组、高住高练耐力组、高住低练耐力组、低住高练耐力组、高住高练后复氧训练组和高住低练后复氧训练组。采用常压低氧仓在13.6%的氧体积分数下(相当于海拔3?500?m的氧体积分数)进行低氧训练,根据血乳酸-速度曲线确定大鼠常氧训练的强度为35?m/min,低氧训练的强度为30?m/min。低氧训练持续时间为6周,每周训练5?d。其中,在第4周末进行运动能力测试,第5周末进行力竭测试,在第6周末的最后一次运动后休息48?h后处死,取材。采用实时荧光定量PCR、免疫组化、Western blot等技术测试大鼠骨骼肌HIF 1α mRNA水平和蛋白水平表达水平的变化,以进一步探讨低氧训练对骨骼肌HIF 1α表达的适应机制。结果显示,与低住低练组相比,高住高练组和高住低练骨骼肌HIF 1αmRNA表达有显著性升高(P<0.05);和常氧安静对照组相比,高住高练骨骼肌HIF 1αmRNA表达升高105%,有非常显著性差异(P<0.01);高住高练后复氧训练1周,大鼠骨骼肌HIF 1αmRNA表达有非常显著性降低(P<0.01),回到常氧安静对照组水平; 高住低练后复氧训练1周,大鼠骨骼肌HIF 1αmRNA表达有显著性降低(P<0.05),回到常氧安静对照组水平。可得结论:高住高练、高住低练和持续低氧安静组骨骼肌HIF 1α表达都明显增强,而低住低练和低住高练变化不大,复氧训练后回到常氧安静水平。HIF 1α表达与低氧的程度和时间有明显的依存关系。 相似文献