固定剂和保存条件对桡足类及其肠道内容物DNA质量的影响OA北大核心CSCDCSTPCD

The DNA barcoding technique has been widely used in studying the diversity of copepods and their diet in situ,serving as a powerful tool for understanding the plankton community structure and marine food web dy-namics.Effective sample preservation is a critical prerequisite for downstream DNA analyses,including PCR am-plification and gene sequencing.In this study,we evaluated the effects of the fixative and storage duration on both the yield and quality of DNA extracted from copepods and their gut contents.DNA integrity was assessed through the qPCR quantification of 18S rDNA fragments with different lengths.Our results showed that RNAlater exhibited optimal performance in fixing and preserving copepod DNA with the highest yield and integrity over a two-month storage period.Ethanol demonstrated the best efficacy in the fixation and preservation of gut content DNA as it exhibits excellent permeability and rapidly terminates the physiological and metabolic activities of copepods and gut microbiota,respectively.Neutral Lugol's solution can achieve immediate or short-term fixation of gut content DNA;however,it is unsuitable for long-term preservation.These findings provide insights into sampling strategies,fixation protocols,and storage conditions for investigating copepods and their diet in situ.They guide the use of appropriate fixatives and preservation conditions based on research priorities(copepod DNA or gut content DNA).