全基因组关联分析(genomewide association study,GWAS)是应用人类基因组中数以百万计的单核苷酸多态性(single nucleotide polymorphism,SNP)为标记进行病例-对照关联分析,以期发现影响复杂性疾病发生的遗传特征的一种新策略。近年来,...全基因组关联分析(genomewide association study,GWAS)是应用人类基因组中数以百万计的单核苷酸多态性(single nucleotide polymorphism,SNP)为标记进行病例-对照关联分析,以期发现影响复杂性疾病发生的遗传特征的一种新策略。近年来,随着人类基因组计划和基因组单倍体图谱计划的实施,人们已通过GWAS方法发现并鉴定了大量与人类性状或复杂性疾病关联的遗传变异,为进一步了解控制人类复杂性疾病发生的遗传特征提供了重要的线索。然而,由于造成复杂性疾病/性状的因素较多,而且GWAS研究系统较为复杂,因此目前GWAS本身亦存在诸多的问题。本文将从研究方式、研究对象、遗传标记,以及统计分析等方面,探讨GWAS的研究现状以及存在的潜在问题,并展望GWAS今后的发展方向。展开更多
Plants assimilate inorganic nitrogen absorbed from soil into organic forms as Gin and Glu through the glutamine synthetase/glutamine：2-oxoglutarate amidotransferase （GS/GOGAT） cycle. Whereas GS cata- lyzes the form...Plants assimilate inorganic nitrogen absorbed from soil into organic forms as Gin and Glu through the glutamine synthetase/glutamine：2-oxoglutarate amidotransferase （GS/GOGAT） cycle. Whereas GS cata- lyzes the formation of Gin from Glu and ammonia, GOGAT catalyzes the transfer of an amide group from Gin to 2-oxoglutarate to produce two molecules of Glu. However, the regulatory role of the GS/GOGAT cycle in the carbon-nitrogen balance is not well understood. Here, we report the functional characterization of rice ABNORMAL CYTOKININ RESPONSE 1 （ABC1） gene that encodes a ferredoxin-dependent （Fd）- GOGAT. The weak mutant allele abcl-1 mutant shows a typical nitrogen-deficient syndrome, whereas the T-DNA insertional mutant abcl-2 is seedling lethal. Metabolomics analysis revealed the accumulation of an excessive amount of amino acids with high N/C ratio （Gin and Asn） and several intermediates in the tricarboxylic acid cycle in abcl-1, suggesting that ABC1 plays a critical role in nitrogen assimilation and carbon-nitrogen balance. Five non-synonymous single-nucleotide polymorphisms were identified in the ABC1 coding region and characterized as three distinct haplotypes, which have been highly and specifically differentiated between japonica and indica subspecies. Collectively, these results suggest that ABC1/ OsFd-GOGAT is essential for plant growth and development by modulating nitrogen assimilation and the carbon-nitrogen balance.展开更多
文摘全基因组关联分析(genomewide association study,GWAS)是应用人类基因组中数以百万计的单核苷酸多态性(single nucleotide polymorphism,SNP)为标记进行病例-对照关联分析,以期发现影响复杂性疾病发生的遗传特征的一种新策略。近年来,随着人类基因组计划和基因组单倍体图谱计划的实施,人们已通过GWAS方法发现并鉴定了大量与人类性状或复杂性疾病关联的遗传变异,为进一步了解控制人类复杂性疾病发生的遗传特征提供了重要的线索。然而,由于造成复杂性疾病/性状的因素较多,而且GWAS研究系统较为复杂,因此目前GWAS本身亦存在诸多的问题。本文将从研究方式、研究对象、遗传标记,以及统计分析等方面,探讨GWAS的研究现状以及存在的潜在问题,并展望GWAS今后的发展方向。
文摘Plants assimilate inorganic nitrogen absorbed from soil into organic forms as Gin and Glu through the glutamine synthetase/glutamine：2-oxoglutarate amidotransferase （GS/GOGAT） cycle. Whereas GS cata- lyzes the formation of Gin from Glu and ammonia, GOGAT catalyzes the transfer of an amide group from Gin to 2-oxoglutarate to produce two molecules of Glu. However, the regulatory role of the GS/GOGAT cycle in the carbon-nitrogen balance is not well understood. Here, we report the functional characterization of rice ABNORMAL CYTOKININ RESPONSE 1 （ABC1） gene that encodes a ferredoxin-dependent （Fd）- GOGAT. The weak mutant allele abcl-1 mutant shows a typical nitrogen-deficient syndrome, whereas the T-DNA insertional mutant abcl-2 is seedling lethal. Metabolomics analysis revealed the accumulation of an excessive amount of amino acids with high N/C ratio （Gin and Asn） and several intermediates in the tricarboxylic acid cycle in abcl-1, suggesting that ABC1 plays a critical role in nitrogen assimilation and carbon-nitrogen balance. Five non-synonymous single-nucleotide polymorphisms were identified in the ABC1 coding region and characterized as three distinct haplotypes, which have been highly and specifically differentiated between japonica and indica subspecies. Collectively, these results suggest that ABC1/ OsFd-GOGAT is essential for plant growth and development by modulating nitrogen assimilation and the carbon-nitrogen balance.
