3:30 PM - 3:45 PM
[AOS18-01] DNA metabarcoding focused on plankton as an effective approach for the reconstruction of past environment
Keywords:environmental DNA, sedaDNA, protist, sedimentary core, taxonomy
The DNA metabarcoding (DNA-MB) is widely used to thoroughly clarify the composition of plankton contained in environmental samples. This method is useful not only in biological studies but also in sedimentary surveys. The DNA-MB focused on plankton demands wide knowledge on diverse taxa, and correct reference DNA sequences are also indispensable. Partly because of these reasons, the DNA-MB focused on plankton community has scarcely been conducted in the field of sedimentary sciences. On the other hand, such analysis could be effective to elucidate the past environment because the plankton community contains the primary producers. Moreover, plankton possess large biomass and respond sensitively to environmental changes.
To confirm the effectiveness of the DNA metabarcoding focused on plankton, two types of surveys were conducted in Lake Shinji, Japan. The salinity of this lake is low (the PSU is ca. 5), but previous studies clarified that it was a semi-closed bay filled with sea water before Christ. (1) A sedimentary core of ca. 4 m in depth was sampled in July 2021 from the center of the lake. (2) Water and surface sediments were also sampled each month during the period from May 2020 to March 2021, in order to compare the taxonomic composition in water columns and sediments. The DNA-MB focused on plankton community was conducted for both samples.
(1) The first survey revealed that the habitats of the detected plankton were drastically changed among the samples upper and lower than ca. 2.5 m in depth, and the age of this depth was estimated at A.D. 1250–90. (2) The second survey clarified that the taxonomic composition was largely different between the water and sedimentary samples, indicating that the results of the first survey needs to be corrected when we discuss about the fluctuations in taxonomic composition.
To confirm the effectiveness of the DNA metabarcoding focused on plankton, two types of surveys were conducted in Lake Shinji, Japan. The salinity of this lake is low (the PSU is ca. 5), but previous studies clarified that it was a semi-closed bay filled with sea water before Christ. (1) A sedimentary core of ca. 4 m in depth was sampled in July 2021 from the center of the lake. (2) Water and surface sediments were also sampled each month during the period from May 2020 to March 2021, in order to compare the taxonomic composition in water columns and sediments. The DNA-MB focused on plankton community was conducted for both samples.
(1) The first survey revealed that the habitats of the detected plankton were drastically changed among the samples upper and lower than ca. 2.5 m in depth, and the age of this depth was estimated at A.D. 1250–90. (2) The second survey clarified that the taxonomic composition was largely different between the water and sedimentary samples, indicating that the results of the first survey needs to be corrected when we discuss about the fluctuations in taxonomic composition.