New Dr. in ABRU

On March 13th 2020 ABRU’s Iines Salonen successfully defended her doctoral thesis entitled ”Exploring the composition, variation and interactions of unicellular organisms in the marine benthic community with DNA metabarcoding”, with Dr. Francisco Nascimento from Stockholm University acting as her opponent. Iines' defence was the last to take place in traditional settings before the pandemic-related University lockdown. Thus Friday the 13th proved to be a very lucky and successful day for Iines in many ways.

In her thesis, Iines explored the use of DNA metabarcoding as a tool for identifying marine benthic eukaryote and prokaryote community composition. She also focused on the ecological-biogeochemical interactions of foraminifera, an important group of benthic unicellular eukaryotes in the global oceans. To track temporal variations in eukaryote communities in coastal sediments of the Gulf of Finland, Iines used 18S rDNA metabarcoding, demonstrating the potential of DNA metabarcoding in marine environmental monitoring. This approach, in comparison to traditional assessment methods, has the advantage of providing information about a large range of species simultaneously and for relatively low sampling effort. For a more detailed look on trophic strategies and microbial interactions of foraminifera, Iines employed both 18S and 16S rDNA metabarcoding, targeting the intracellular bacteria and eukaryotes of foraminifera as well as the foraminifera’s DNA itself. The trophic preferences of the investigated species Haynesina sp., Elphidium sp, and Ammonia sp. could be identified by their intracellular eukaryote communities, which gave not only information on the foraminiferal diet but also their life strategy and ecology, important for understanding their role in sediment biogeochemical cycles.

This thesis was supervised by Dr. Karoliina Koho and Doc. Elina Leskinen, and funded by the Academy of Finland as well as the Walter and Andrée de Nottbeck foundation.

Iines Salonen answering questions at the defence


Iines Salonen and Karoliina Koho