[Objective] The aim was to isolate the triazophos-degrading strain and study its degradation characteristics. [Method] A triazophos-degrading bacterium strain C-Y106 was isolated from sludge in an aeration tank of tri...[Objective] The aim was to isolate the triazophos-degrading strain and study its degradation characteristics. [Method] A triazophos-degrading bacterium strain C-Y106 was isolated from sludge in an aeration tank of triazophos manufacture. Then the strain C-Y106 was identified according to the morphology,physiological and biochemical characteristics,and 16S rRNA sequence analysis. The effect of medium with different nutrients on triazophos-degrading rate by C-Y106 was studied. [Result] The strain C-Y106 was identified as Bacillus subtilis. The strain C-Y106 could grow in the mineral salt medium with 40 mg/L of triazophos as the sole sources of carbon,Nitrogen and Phosphorus. The triazophos-degrading rate was the highest as 76.8% in the mineral salt medium with 40 mg/L of triazophos as the sole source of Phosphorus,after being incubated at 31 ℃,pH 8.0 and 150 r/min for 60 h. [Conclusion] The research had provided theoretical basis for the identification and purification of enzymes for triazophos degradation.展开更多
A comparative analysis of the codon usage bias was conducted in Methanosarcina mazei str. Goel and two related Euryarchaeota microorganisms （Picrophilus torridus str. DSM 9790 and Natronomonas pharaonis str. DSM 2160...A comparative analysis of the codon usage bias was conducted in Methanosarcina mazei str. Goel and two related Euryarchaeota microorganisms （Picrophilus torridus str. DSM 9790 and Natronomonas pharaonis str. DSM 2160）. Results revealed that synonymous codon usage in Methanosarcina mazei str. Goel was less biased, which was highly correlated with the GC3S value. And the codon usage patterns were phylogenetically conserved among those Euryarchaeota microorganisms. By employing a hierarchical clustering analysis, it can be seen that it is more the species than the gene function that determines their gene codon usage pattems. Considering that those microorganisms live in different environments where the pH conditions vary quite a lot, it can be presumed that their living environments, especially the pH conditions, play an important role in determining those microorganisms＇ codon usage pattems.展开更多
短串联重复序列(short tandem repeat,STR)遗传标记在法庭科学DNA鉴定中占据绝对主导地位,包括中国在内的世界各国DNA数据库均基于STR遗传标记建立。STR遗传标记具有长度多态性和序列多态性。序列多态包括重复区和侧翼区序列的多态性。...短串联重复序列(short tandem repeat,STR)遗传标记在法庭科学DNA鉴定中占据绝对主导地位,包括中国在内的世界各国DNA数据库均基于STR遗传标记建立。STR遗传标记具有长度多态性和序列多态性。序列多态包括重复区和侧翼区序列的多态性。传统的基于毛细管电泳技术进行STR分型仅区分长度多态性,而深刻理解核心STR基因座的序列多态对于引物设计和DNA鉴定等方面至关重要。首先,STR扩增引物结合区的SNP、InDel可能干扰引物与DNA模板结合的亲和力,导致无法检测到某些等位基因或均衡性差,影响DNA鉴定准确性;其次,二代测序技术推动STR鉴定由长度多态分型向序列多态分型发展,显著提升了可检测的核心STR基因座多态信息含量,提高了其个体识别和亲缘关系分析效能;再者,不同人群具有不同的STR序列特征。近10年来,基于二代测序的STR序列多态性的研究逐渐增多,多个人群的序列多态性数据已经被报道,但以往的研究群体及数据较为零散,重复序列的数据格式不统一,导致核心STR基因座的序列多态性缺乏来自大数据的系统性总结和梳理。充分掌握核心STR基因座的序列特征对微量检材的个体识别、混合样本拆分、亲子鉴定中突变来源的确定等具有十分重要的意义。本文以19个常染色体核心STR为分析对象,整合了目前文献报道的群体数据和公开数据库中的中国人群变异频率数据,系统综述了这些STR的序列多态性,包括归纳STR基因座重复区的变异类型和分析变异规律,总结了中国人群中STR侧翼区的高频变异,并探讨了在STR序列检验中可能遇到的难点,以期为STR序列的应用解析、案件检验中稀有等位基因的判别以及STR试剂盒的研制等方面提供参考。展开更多
文章通过深入剖析二联体亲权鉴定中短串联重复序列(short tandem repeat sequence,STR)突变率对累积亲权指数(cumulative parental index,CPI)计算的影响并提出应对策略。STR突变率与CPI数值呈显著正相关趋势,STR突变率的提升会增加突...文章通过深入剖析二联体亲权鉴定中短串联重复序列(short tandem repeat sequence,STR)突变率对累积亲权指数(cumulative parental index,CPI)计算的影响并提出应对策略。STR突变率与CPI数值呈显著正相关趋势,STR突变率的提升会增加突变基因座的亲权指数(parental rights index,PI)值,进而推高CPI数值。这种变化在CPI接近判定临界值时,可能直接影响亲权关系判定结果。当出现多基因座突变时,各个基因座突变率相互作用,使CPI的计算更为复杂。为降低STR基因座突变干扰,可通过采取优化检测基因座体系、扩充基因座检测数量以及联合多遗传标记分析等策略,有效提升亲权鉴定结果的准确性与可靠性,为司法实践和社会应用提供科学依据和技术支撑。展开更多
文摘[Objective] The aim was to isolate the triazophos-degrading strain and study its degradation characteristics. [Method] A triazophos-degrading bacterium strain C-Y106 was isolated from sludge in an aeration tank of triazophos manufacture. Then the strain C-Y106 was identified according to the morphology,physiological and biochemical characteristics,and 16S rRNA sequence analysis. The effect of medium with different nutrients on triazophos-degrading rate by C-Y106 was studied. [Result] The strain C-Y106 was identified as Bacillus subtilis. The strain C-Y106 could grow in the mineral salt medium with 40 mg/L of triazophos as the sole sources of carbon,Nitrogen and Phosphorus. The triazophos-degrading rate was the highest as 76.8% in the mineral salt medium with 40 mg/L of triazophos as the sole source of Phosphorus,after being incubated at 31 ℃,pH 8.0 and 150 r/min for 60 h. [Conclusion] The research had provided theoretical basis for the identification and purification of enzymes for triazophos degradation.
文摘A comparative analysis of the codon usage bias was conducted in Methanosarcina mazei str. Goel and two related Euryarchaeota microorganisms （Picrophilus torridus str. DSM 9790 and Natronomonas pharaonis str. DSM 2160）. Results revealed that synonymous codon usage in Methanosarcina mazei str. Goel was less biased, which was highly correlated with the GC3S value. And the codon usage patterns were phylogenetically conserved among those Euryarchaeota microorganisms. By employing a hierarchical clustering analysis, it can be seen that it is more the species than the gene function that determines their gene codon usage pattems. Considering that those microorganisms live in different environments where the pH conditions vary quite a lot, it can be presumed that their living environments, especially the pH conditions, play an important role in determining those microorganisms＇ codon usage pattems.
文摘短串联重复序列(short tandem repeat,STR)遗传标记在法庭科学DNA鉴定中占据绝对主导地位,包括中国在内的世界各国DNA数据库均基于STR遗传标记建立。STR遗传标记具有长度多态性和序列多态性。序列多态包括重复区和侧翼区序列的多态性。传统的基于毛细管电泳技术进行STR分型仅区分长度多态性,而深刻理解核心STR基因座的序列多态对于引物设计和DNA鉴定等方面至关重要。首先,STR扩增引物结合区的SNP、InDel可能干扰引物与DNA模板结合的亲和力,导致无法检测到某些等位基因或均衡性差,影响DNA鉴定准确性;其次,二代测序技术推动STR鉴定由长度多态分型向序列多态分型发展,显著提升了可检测的核心STR基因座多态信息含量,提高了其个体识别和亲缘关系分析效能;再者,不同人群具有不同的STR序列特征。近10年来,基于二代测序的STR序列多态性的研究逐渐增多,多个人群的序列多态性数据已经被报道,但以往的研究群体及数据较为零散,重复序列的数据格式不统一,导致核心STR基因座的序列多态性缺乏来自大数据的系统性总结和梳理。充分掌握核心STR基因座的序列特征对微量检材的个体识别、混合样本拆分、亲子鉴定中突变来源的确定等具有十分重要的意义。本文以19个常染色体核心STR为分析对象,整合了目前文献报道的群体数据和公开数据库中的中国人群变异频率数据,系统综述了这些STR的序列多态性,包括归纳STR基因座重复区的变异类型和分析变异规律,总结了中国人群中STR侧翼区的高频变异,并探讨了在STR序列检验中可能遇到的难点,以期为STR序列的应用解析、案件检验中稀有等位基因的判别以及STR试剂盒的研制等方面提供参考。
文摘文章通过深入剖析二联体亲权鉴定中短串联重复序列(short tandem repeat sequence,STR)突变率对累积亲权指数(cumulative parental index,CPI)计算的影响并提出应对策略。STR突变率与CPI数值呈显著正相关趋势,STR突变率的提升会增加突变基因座的亲权指数(parental rights index,PI)值,进而推高CPI数值。这种变化在CPI接近判定临界值时,可能直接影响亲权关系判定结果。当出现多基因座突变时,各个基因座突变率相互作用,使CPI的计算更为复杂。为降低STR基因座突变干扰,可通过采取优化检测基因座体系、扩充基因座检测数量以及联合多遗传标记分析等策略,有效提升亲权鉴定结果的准确性与可靠性,为司法实践和社会应用提供科学依据和技术支撑。
