2018 - 2021
While our work will include classical microscopic and macroscopic analysis of biological communities, we will heavily focus on applying molecular metabarcoding approaches to obtain integrative species inventories for the ecosystems studied, and track population dynamics back in time by analysis of paleoenvironmental DNA. For the first phase of TransTiP, we will concentrate on invertebrates as ostracods and chironomids, because these groups contain endemic and undescribed species (e.g. Makarchenko and Kobayashi, 1997; Wang, 2000; Yu et al., 2009), and the parallel analysis using classical microfossil techniques (W2 + P1) will allow to cross-evaluate success and results of DNA extraction + metabarcoding. During fieldwork, the postdoctoral researcher will collect living larval + adult specimen in the Nam Co catchment. These will be determined, sorted and used for DNA metabarcoding on Illumina platforms, following and adapting approaches established in the applicant's laboratories (Vences et al., 2016). DNA sequences obtained will be used to extend existing genetic libraries, catch modern haplotype diversity, build regional phylogenetic trees and detect the origin of species endemic on the TP. Sequencing will be carried out in the genome center of the Helmholtz Institute for Infection Research, Braunschweig (regularly collaborating with the Vences lab). Potentially new taxa will be described in cooperation with leading taxonomic experts for the organism groups (E. Makarchenko for chironomids, P. Frenzel for ostracods). Sediment sampling and paleoenvironmental DNA extraction will follow protocols specifically designed for extraction from ancient sediments to avoid contamination with modern material (e.g. Anderson-Carpenter et al., 2011, Rawlence et al., 2014), and analysis take place at the fossil DNA laboratory of the M. Hofreiter (Potsdam University). Analysis on short cores will complement classical microfossil approaches and focus on changes in haplotype diversity that cannot be detected otherwise. Based on our expertise with metabarcoding and eDNA analyses we are fully convinced that metabarcoding of extant organisms will be successful and generate a large set of highly relevant data, leading to a very efficient and objective high-throughput inventory of current freshwater diversity in the study system. In contrast, we are aware that metabarcoding of ancient DNA is challenging and will require solving numerous practical problems. By collaborating with the Hofreiter lab (specialized in ancient DNA) we are however optimistic to overcome these challenges and thereby provide pioneering studies in the molecular ecology of ancient freshwater communities.
Prof. Dr. Antje Schwalb, TU Braunschweig
Prof. Dr. Miguel Vences, TU Braunschweig (2018 - 2020)
Prof. Dr. Fahu Chen, ITP