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排序方式: 共有1109条查询结果,搜索用时 18 毫秒
71.
72.
JIANG WenXi QIU ChangChun CHENG ZuHeng ZHOU WenYu GU MingLiang XU Qun FANG MingWu & NIU WenQuan 《中国科学:生命科学英文版》2007,50(1):80-87
This paper investigated the correlation between polymorphisms and haplotypes in the apolipoprotein B (apoB) gene (SP-I/D, XbaI-RFLP, VNTR) and natural longevity persons among the Uygur people in Xin-jiang. For this purpose, 191 healthy Uygur individuals aged above 90 from Hetian area of Xinjiang were recruited, and another 53 persons aged 65—70 from the same nationality, the same region and with the same gender ratio, served as the control group. Genotyping was performed by PCR-SSP, PCR-RFLP and PCR-sequencing methods. Logistic regression analyses revealed that the frequencies of X X genotype, M and L alleles and the genetypes composed of M and L were significantly higher in the longevity group than in the control group. In haplotype analyses, we found that, in the long-lived people, the frequency of haplotypes composed of the X and M alleles was significantly higher whereas the frequency of haplotypes composed of the X- and S alleles was significantly lower (both P<0.05) I than those of their controls. These results indicated that the S allele, SS genotype and X -S, D-S, D-X -S haplotypes were the possible adverse factors, whereas the M, L alleles, X X , MM, ML, LL genotypes and I-X -M, X -M haplotypes were the possibe protective factors for the naturally long-lived Uygur people in China. 相似文献
73.
Effects of endophyte fungal species and host plant genotype on the leaf shape and leaf area of endophyte-grass symbionts 下载免费PDF全文
《植物生态学报》1958,44(6):654
Epichloë内生真菌感染能够影响宿主植物的生长发育, 但关于内生真菌感染对宿主植物叶形状和叶面积的研究很少。该研究以羽茅(Achnatherum sibiricum)为实验材料, 采用长宽系数计算和扫描测定叶面积相结合的方法探究内生真菌种类和羽茅母本基因型对羽茅-内生真菌共生体叶形状和叶面积的影响。结果表明: 内生真菌感染与否、内生真菌种类和宿主母本基因型对反映叶形状的叶校正系数、叶片长度、宽度和长宽比均无显著影响, 经计算与验证, 确定了羽茅叶片的校正系数为0.594 9。采用该校正系数及叶长宽计算的叶面积与实测叶面积无显著差异, 且二者均未受到内生真菌感染与否、内生真菌种类或宿主植物母本基因型的显著影响。 相似文献
74.
Adam C. Naj Honghuang Lin Badri N. Vardarajan Simon White Daniel Lancour Yiyi Ma Michael Schmidt Fangui Sun Mariusz Butkiewicz William S. Bush Brian W. Kunkle John Malamon Najaf Amin Seung Hoan Choi Kara L. Hamilton-Nelson Sven J. van der Lee Namrata Gupta Daniel C. Koboldt Anita L. DeStefano 《Genomics》2019,111(4):808-818
The Alzheimer's Disease Sequencing Project (ADSP) performed whole genome sequencing (WGS) of 584 subjects from 111 multiplex families at three sequencing centers. Genotype calling of single nucleotide variants (SNVs) and insertion-deletion variants (indels) was performed centrally using GATK-HaplotypeCaller and Atlas V2. The ADSP Quality Control (QC) Working Group applied QC protocols to project-level variant call format files (VCFs) from each pipeline, and developed and implemented a novel protocol, termed “consensus calling,” to combine genotype calls from both pipelines into a single high-quality set. QC was applied to autosomal bi-allelic SNVs and indels, and included pipeline-recommended QC filters, variant-level QC, and sample-level QC. Low-quality variants or genotypes were excluded, and sample outliers were noted. Quality was assessed by examining Mendelian inconsistencies (MIs) among 67 parent-offspring pairs, and MIs were used to establish additional genotype-specific filters for GATK calls. After QC, 578 subjects remained. Pipeline-specific QC excluded ~12.0% of GATK and 14.5% of Atlas SNVs. Between pipelines, ~91% of SNV genotypes across all QCed variants were concordant; 4.23% and 4.56% of genotypes were exclusive to Atlas or GATK, respectively; the remaining ~0.01% of discordant genotypes were excluded. For indels, variant-level QC excluded ~36.8% of GATK and 35.3% of Atlas indels. Between pipelines, ~55.6% of indel genotypes were concordant; while 10.3% and 28.3% were exclusive to Atlas or GATK, respectively; and ~0.29% of discordant genotypes were. The final WGS consensus dataset contains 27,896,774 SNVs and 3,133,926 indels and is publicly available. 相似文献
75.
弱光胁迫对不同基因型玉米生长发育和产量的影响 总被引:59,自引:5,他引:54
以不同基因型玉米为材料,在玉米生长发育的3个主要阶段(苗期、穗期、粒期)进行分期遮光试验,研究不同时期弱光胁迫对不同基因型玉米生长发育和产量的影响。结果表明,遮光延缓了玉米叶片的出生速度,使叶片变薄;遮光可以延缓叶片的衰老,但遮光解除后则加速叶片的衰老;遮光造成植株高度增加,但恢复正常光照后,其株高却逐渐低于对照;遮光使干物质积累下降,抽雄吐丝日期推迟,尤其是吐丝日期推迟更多,并使产量降低,但不同基因型玉米不同遮光处理下降程度不同。试验的4个品种中,掖单2 2和豫玉2号受遮光影响较小,而掖单36 38和丹玉13受影响较大,即不同基因型玉米对弱光胁迫的敏感性不同 相似文献
76.
SUN Xiangqing * JIA Yanbin * ZHANG Xuegong XU Qi SHEN Yan & LI Yanda . Ministry of Education 《中国科学:生命科学英文版》2005,48(3):263-269
Schizophrenia is a serious neuropsychiatric illness affecting about 1% of the world’s population. Family, twin and adoption studies have demonstrated that 65%―85% of the susceptibility to schizophrenia can be attributed to genes. On the basis of genetic model-ing of epidemiological data and recent results of a number of whole-genome screens for susceptibility genes, schizophrenia has been considered a complex disorder. A number of genes with small to moderate effects are involved in combinat… 相似文献
77.
北京地区呼吸道合胞病毒分离株G蛋白基因遗传变异特性研究 总被引:1,自引:0,他引:1
为了解北京地区人呼吸道合胞病毒(human respiratory syncytial virus,HRSV)的遗传变异和分子流行病学特征,首次对北京地区2003~2004年63株HRSV分离株进行了G基因3’末端的第2个高度变异区的序列测定,并进行了基因分型和遗传变异的分析。使用不同的型特异性引物对GPA—F1和GPB-F1分别扩增A、B血清型HRSVG基因3’末端核苷酸序列,特异性扩增产物和随后的序列测定结果均显示,北京地区2003~2004年63株HRSV毒株中,96.8%(61/63)为A血清型,3.2%(2/63)为B血清型,说明北京地区在2003~2004年间存在HRSVA、B血清型共循环,但以A血清型病毒为主。分别对北京流行的A和B血清型病毒进行了基因亲缘性关系分析,结果提示,61株北京A血清型分离株全部为GA2基因型;2株B血清型分离株为GB3基因型。由此看来,GA2基因型是北京地区2003~2004年的优势流行基因型。北京61株GA2分离株之问核苷酸和氨基酸同源性分别在87.8%~100%和77.9%~100%之间;2株B血清型分离株之间核苷酸和氨基酸同源性分别为94.7%和88.1%。这说明在2003年和2004年有很多个不同的GA2基因型HRSV毒株在北京地区共循环,北京地区的HRSV流行存在着许多由不同病毒株引起的传播链。B血清型分离株Beijing04-11于G基因3’末端含有一个60个碱基的重复序列,这是HRSV多聚酶易于重复复制限定序列的一个极端的例子,有可能是HRSV逃逸免疫压力而不断进化的一种方式。该研究首次对北京地区2003年和2004年流行的HRSV进行了基因分型和遗传变异的研究,对于了解北京HRSV流行株的基因特征具有重要意义,可以为北京乃至中国疫苗株的选择提供参考依据,从而指导HRSV的免疫预防控制。 相似文献
78.
79.
Variability in the developmental stage of apricot ovules at anthesis and its relationship with fruit set 总被引:1,自引:0,他引:1
The stage of ovule development at anthesis and its relationship with fruit set was studied in several apricot cultivars growing in Mediterranean climatic conditions. Although generally the ovule was immature at anthesis, a great variability was found in the stage of development of the ovules from different cultivars. Considering functional ovules to be those with an embryo sac with at least four nuclei at anthesis, the earliest flowering varieties frequently showed more than 50% of functional ovules. Though these results could suggest that there is an influence of the chilling requirement on the percentage of functional ovules at anthesis, data recorded from two cultivars, ‘Goldrich’ and ‘Colorao’, with high chilling requirements, contrast with this suggestion. These results indicate that in apricot flowers the development of the embryo sac at anthesis is genotype dependent. The fact that a high frequency of functional ovules at anthesis was found, in cultivars with more than 50% of fruit set, suggests that, to be fertilised, a certain level of development of the apricot ovules at this time is necessary. 相似文献
80.
代谢工程分为推理性代谢工程和逆代谢工程,逆代谢工程是避开对代谢网络充分认识的一种全新的遗传工程。本简要介绍了逆代谢工程的策略,并以实例详细分析了逆代谢工程的具体应用,最后,分析了逆代谢工程的问题和发展前景。 相似文献