You are here:
Highlighting the promise of qPCR-based environmental monitoring: response of the ribosomal RNA:DNA ratio of calanoid copepods totoxic cyanobacteria
Citation:
Banerji, A., R. Deshpande, M. Elk, J. Shoemaker, Dan Tettenhorst, M. Bagley, AND J. SantoDomingo. Highlighting the promise of qPCR-based environmental monitoring: response of the ribosomal RNA:DNA ratio of calanoid copepods totoxic cyanobacteria. Ecotoxicology. Springer, New York, NY, 30:411-420, (2021). https://doi.org/10.1007/s10646-021-02366-w
Impact/Purpose:
Copepods are important members of aquatic communities that have been suggested as potential indicators of water quality, including for toxic cyanobacteria blooms. This work was conducted to develop the first molecular method to determine the presence, relative abundance and activity to one copepod group, the calanoids.
Description:
Like many other zooplankton species, copepods are monitored using cumbersome techniques that do not facilitate studying their occurrence and metabolic activity in natural systems. In this study, we used 18S rRNA gene sequencing analyses to identify the predominant calanoid copepod population within a eutrophic freshwater lake and to develop a qPCR assay to examine their population dynamics. DNA and RNA extracted from water samples collected over a five-month period from five different sites were used as qPCR templates to examine the relative abundance and activity of calanoids. 18S rRNA gene (rDNA) and rRNA-based qPCR data showed that calanoid densities fluctuated up to five orders of magnitude during the study. The most dramatic fluctuations were observed in early-May, mid-June, and late-September. There was a positive correlation between rDNA- and rRNA-based data in all sites. Most samples (i.e., 79%) showed relatively low rRNA:rDNA ratios (<2), although the ratios changed at least three fold on 27% to 50% of consecutive sampling dates. Additionally, there were significant differences in rDNA, rRNA, and rRNA:rDNA ratio between sites, a factor that needs to be considered when studying these organisms in aquatic systems. This study demonstrates an alternate approach to more rapidly assess the changes in the distribution and overall activity of predominant zooplankton in natural water systems.
URLs/Downloads:
DOI: Highlighting the promise of qPCR-based environmental monitoring: response of the ribosomal RNA:DNA ratio of calanoid copepods totoxic cyanobacteria
Free access through PubMed Central