目的采用高通量测序技术,对一个综合征型耳聋家系的致病变异进行鉴定。方法详细询问一综合征型耳聋家系的病史及家族史,绘制家系图。对该家系进行听力学检查,采用全外显子组测序及生物信息学分析,筛选疑似致病变异,使用Sanger测序进行...目的采用高通量测序技术,对一个综合征型耳聋家系的致病变异进行鉴定。方法详细询问一综合征型耳聋家系的病史及家族史,绘制家系图。对该家系进行听力学检查,采用全外显子组测序及生物信息学分析,筛选疑似致病变异,使用Sanger测序进行变异共分离验证,并通过转录组测序探究内含子对剪切的影响。结果该家系中先证者(男性,2岁2个月)患有听神经病,伴有发育缓慢、肌无力、癫痫发作等症状。患者携带NARS2(NM_024678.6)c.[779A>C];[372+3A>G]复合杂合变异,其中c.779A>C p.(Glu260Ala)遗传自父亲,c.372+3A>G遗传自母亲,两变异均未见文献报道或数据库收录。转录组测序结果表明c.372+3A>G变异会导致转录跳过第三个外显子。依据美国医学遗传学与基因组学学会(American College of Medical Genetics and Genomics,ACMG)相关指南将c.779A>C变异及c.372+3A>G变异评级为可能致病。基于患者表型及基因检测结果,该患者诊断为联合氧化磷酸化缺乏症24型。结论NARS2基因致病变异可能是该患者的致病原因,新变异的检出丰富了NARS2基因的变异谱,为进一步明确NARS2与联合氧化磷酸化缺乏症24型的关系提供了参考依据。展开更多
Rice has a preference for uptake of ammonium over nitrate and can use ammonium-N efficiently. Consequently, transporters mediating ammonium uptake have been extensively studied, but nitrate transporters have been larg...Rice has a preference for uptake of ammonium over nitrate and can use ammonium-N efficiently. Consequently, transporters mediating ammonium uptake have been extensively studied, but nitrate transporters have been largely ignored. Recently, some reports have shown that rice also has high capacity to acquire nitrate from growth medium, so understanding the nitrate transport system in rice roots is very important for improving N use efficiency in rice. The present study Identified four putative NRT2 and two putative NAR2 genes that encode components of the high-affinity nitrate transport system （HATS） in the rice （Oryza sativa L. subsp, japonica cv. Nipponbare） genome. OsNRT2.1 and OsNRT2.2 share an Identical coding region sequence, and their deduced proteins are closely related to those from mono-cotyledonous plants. The two NAR2 proteins are closely related to those from mono-cotyledonous plants as well. However, OsNRT2.3 and OsNRT2.4 are more closely related to Arabidopsis NRT2 proteins. Relative quantitative reverse trsnscription-polymerase chain reaction analysis showed that all of the six genes were rapidly upregulated and then downrsgulated in the roots of N-starved rice plants after they were re-supplied with 0.2 mM nitrate, but the response to nitrate differed among gene members. The results from phylogenetic tree, gene structure and expression analysis implied the divergent roles for the Individual members of the rice NRT2 and NAR2 families. High-affinity nitrate influx rates associated with nitrate induction in rice roots were investigated and were found to be regulated by external pH. Compared with the nitrate influx rates at pH 6.5, alkaline pH （pH 8.0） inhibited nitrate influx, and acidic pH （pH 5.0） enhanced the nitrate influx in 1 h nitrate induced roots, but did not significantly affect that in 4 to 8 h nitrate induced roots.展开更多
文摘目的采用高通量测序技术,对一个综合征型耳聋家系的致病变异进行鉴定。方法详细询问一综合征型耳聋家系的病史及家族史,绘制家系图。对该家系进行听力学检查,采用全外显子组测序及生物信息学分析,筛选疑似致病变异,使用Sanger测序进行变异共分离验证,并通过转录组测序探究内含子对剪切的影响。结果该家系中先证者(男性,2岁2个月)患有听神经病,伴有发育缓慢、肌无力、癫痫发作等症状。患者携带NARS2(NM_024678.6)c.[779A>C];[372+3A>G]复合杂合变异,其中c.779A>C p.(Glu260Ala)遗传自父亲,c.372+3A>G遗传自母亲,两变异均未见文献报道或数据库收录。转录组测序结果表明c.372+3A>G变异会导致转录跳过第三个外显子。依据美国医学遗传学与基因组学学会(American College of Medical Genetics and Genomics,ACMG)相关指南将c.779A>C变异及c.372+3A>G变异评级为可能致病。基于患者表型及基因检测结果,该患者诊断为联合氧化磷酸化缺乏症24型。结论NARS2基因致病变异可能是该患者的致病原因,新变异的检出丰富了NARS2基因的变异谱,为进一步明确NARS2与联合氧化磷酸化缺乏症24型的关系提供了参考依据。
基金the National Natural Science Foundation of China (30390080and 30521001)the Ministry of Science and Technology of China(2005CB120900 and 2004CB117200)
文摘Rice has a preference for uptake of ammonium over nitrate and can use ammonium-N efficiently. Consequently, transporters mediating ammonium uptake have been extensively studied, but nitrate transporters have been largely ignored. Recently, some reports have shown that rice also has high capacity to acquire nitrate from growth medium, so understanding the nitrate transport system in rice roots is very important for improving N use efficiency in rice. The present study Identified four putative NRT2 and two putative NAR2 genes that encode components of the high-affinity nitrate transport system （HATS） in the rice （Oryza sativa L. subsp, japonica cv. Nipponbare） genome. OsNRT2.1 and OsNRT2.2 share an Identical coding region sequence, and their deduced proteins are closely related to those from mono-cotyledonous plants. The two NAR2 proteins are closely related to those from mono-cotyledonous plants as well. However, OsNRT2.3 and OsNRT2.4 are more closely related to Arabidopsis NRT2 proteins. Relative quantitative reverse trsnscription-polymerase chain reaction analysis showed that all of the six genes were rapidly upregulated and then downrsgulated in the roots of N-starved rice plants after they were re-supplied with 0.2 mM nitrate, but the response to nitrate differed among gene members. The results from phylogenetic tree, gene structure and expression analysis implied the divergent roles for the Individual members of the rice NRT2 and NAR2 families. High-affinity nitrate influx rates associated with nitrate induction in rice roots were investigated and were found to be regulated by external pH. Compared with the nitrate influx rates at pH 6.5, alkaline pH （pH 8.0） inhibited nitrate influx, and acidic pH （pH 5.0） enhanced the nitrate influx in 1 h nitrate induced roots, but did not significantly affect that in 4 to 8 h nitrate induced roots.
