Abstract We investigated aminoacyl-tRNA synthetases (AARS) activity and individual growth rate (IGR) as individual-based in situ indicators of growth in adult krill, Euphausia pacifica. AARS enzymes catalyze the first step in protein synthesis while the IGR method is based on changes in body length during molting. Growth rates of field-collected krill were measured via the IGR method and individuals were subsequently preserved for AARS analysis to yield paired measurements. Our results show that conditions during the IGR incubation period influenced AARS activity in these individuals precluding a direct comparison but revealing the different timescales across which these two measures integrate. Importantly, they show that AARS activity provides a snap-shot image of an organism's metabolism, while IGR of krill is thought to integrate their environmental experience over several days. Each method would require repeated measurements to estimate population growth rates integrated over seasonal or generational time scales. As part of this project, we investigated how specific the AARS assay is to protein synthesis by testing a modified protocol that includes an additional blank and found evidence that the current assay may be measuring other cellular processes in addition to its intended signal. Our results suggest that a new NADH Blank might be optimized to improve the specificity of the assay.

中文翻译：

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个体生长率 (IGR) 和氨酰 tRNA 合成酶 (AARS) 活性作为北太平洋磷虾、太平洋磷虾生长率的个体指标

摘要 我们研究了氨酰 tRNA 合成酶 (AARS) 活性和个体生长率 (IGR) 作为基于个体的太平洋磷虾成年磷虾生长的原位指标。AARS 酶催化蛋白质合成的第一步，而 IGR 方法基于蜕皮过程中体长的变化。通过 IGR 方法测量田间采集的磷虾的生长率，随后保存个体用于 AARS 分析以产生配对测量值。我们的结果表明，IGR 潜伏期的条件影响了这些个体的 AARS 活动，排除了直接比较，但揭示了这两种措施整合的不同时间尺度。重要的是，他们表明 AARS 活动提供了生物体新陈代谢的快照图像，而磷虾的 IGR 被认为在几天内整合了他们的环境经验。每种方法都需要重复测量以估计在季节性或世代时间尺度上整合的人口增长率。作为该项目的一部分，我们通过测试包含额外空白的修改方案来研究 AARS 测定对蛋白质合成的特异性，并发现证据表明当前测定可能正在测量除预期信号之外的其他细胞过程。我们的结果表明，可以优化新的 NADH 空白以提高检测的特异性。我们通过测试包含额外空白的修改方案来研究 AARS 测定对蛋白质合成的特异性，并发现证据表明当前测定可能正在测量除其预期信号之外的其他细胞过程。我们的结果表明，可以优化新的 NADH 空白以提高检测的特异性。我们通过测试包含额外空白的修改方案来研究 AARS 测定对蛋白质合成的特异性，并发现证据表明当前测定可能正在测量除其预期信号之外的其他细胞过程。我们的结果表明，可以优化新的 NADH 空白以提高检测的特异性。