Incorporation characteristics of exogenous 15N-labeled thymidine, deoxyadenosine, deoxyguanosine and deoxycytidine into bacterial DNA
Incorporation characteristics of exogenous 15N-labeled thymidine, deoxyadenosine, deoxyguanosine and deoxycytidine into bacterial DNA
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DOI：
10.1371/journal.pone.0229740
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发表时间：
2020-02
期刊：
影响因子：
3.7
通讯作者：
K. Tsuchiya;T. Sano;N. Tomioka;A. Kohzu;Kazuhiro Komatsu;R. Shinohara;S. Shimode;T. Toda;A. Imai
中科院分区：
文献类型：
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作者：
K. Tsuchiya;T. Sano;N. Tomioka;A. Kohzu;Kazuhiro Komatsu;R. Shinohara;S. Shimode;T. Toda;A. Imai
细菌产量通常通过使用氚标记胸腺嘧啶从DNA合成率估计。一些细菌物种不能将细胞外胸苷结合到它们的DNA中，这表明在使用传统方法时，它们的生物量产生可能被忽视。为了从DNA合成的角度评价脱氧核糖核苷对天然细菌群落细菌产量的适宜性，本研究于2015年7月和2016年1月分别在海洋（相模湾）和淡水（Kasumigaura湖）生态系统中检测了氮稳定同位素（15N）标记的4种脱氧核糖核苷（胸苷、脱氧腺苷、脱氧鸟苷和脱氧胞苷）在细菌DNA中的结合率。在相模湾和Kasumigaura湖的大部分站点，我们发现脱氧鸟苷的掺入率是4种脱氧核糖核苷中最高的，脱氧鸟苷的掺入率大约是胸腺嘧啶的2.5倍。脱氧腺苷和脱氧胞苷的掺入率分别是胸苷的0.9倍和0.2倍。这些结果清楚地表明，与其他脱氧核糖核苷相比，能够将外源性脱氧鸟苷整合到DNA中的细菌物种数量相对较多，使用脱氧鸟苷测量细菌产量更有可能反映出更多的细菌物种产量。
Bacterial production has been often estimated from DNA synthesis rates by using tritium-labeled thymidine. Some bacteria species cannot incorporate extracellular thymidine into their DNA, suggesting their biomass production might be overlooked when using the conventional method. In the present study, to evaluate appropriateness of deoxyribonucleosides for evaluating bacterial production of natural bacterial communities from the viewpoint of DNA synthesis, incorporation rates of four deoxyribonucleosides (thymidine, deoxyadenosine, deoxyguanosine and deoxycytidine) labeled by nitrogen stable isotope (15N) into bacterial DNA were examined in both ocean (Sagami Bay) and freshwater (Lake Kasumigaura) ecosystems in July 2015 and January 2016. In most stations in Sagami Bay and Lake Kasumigaura, we found that incorporation rates of deoxyguanosine were the highest among those of the four deoxyribonucleosides, and the incorporation rate of deoxyguanosine was approximately 2.5 times higher than that of thymidine. Whereas, incorporation rates of deoxyadenosine and deoxycytidine were 0.9 and 0.2 times higher than that of thymidine. These results clearly suggest that the numbers of bacterial species which can incorporate exogenous deoxyguanosine into their DNA are relatively greater as compared to the other deoxyribonucleosides, and measurement of bacterial production using deoxyguanosine more likely reflects larger numbers of bacterial species productions.