Tanja Slotte receives funding from the Knut and Alice Wallenberg Foundation

Six research projects at Stockholm University got funded this year, one of which is Tanja Slotte’s project entitled “Harnessing evolutionary transitions, machine learning, and genomics to decode pollen evolution and unravel sexual selection mechanisms shared across kingdoms”. Co-applicants on the project are Prof John Fitzpatrick, Dr Allison Hsiang, and Prof Catarina Rydin, all at Stockholm University.

The inner parts of the flower of flower flax (Linum grandiflorum) with purple pollen grains visible. Photo: Aleksandra Losvik/Stockholm University

The aim of this project is to test an evolutionary hypothesis on how evolutionary transitions affect the evolution of reproductive cells. In animals, transitions between external and internal fertilization are known to have major consequences for the rate and mode of sperm evolution. This is because the mode of fertilization affects how much sperm are diluted prior to reaching the egg cell (“dilution effects”). Evolutionary transitions between insect and wind pollination in flowering plants should result in similar effects, as pollen is less concentrated prior to fertilization when dispersed by the wind rather than an efficient insect pollinator. However, although there have been more than 40 shifts from insect to wind pollination across flowering plants, no study has yet comprehensively tested how these evolutionary shifts impact pollen evolution. If the same underlying mechanisms that shapes sperm evolution in animals also shapes pollen evolution, shifts from insect to wind pollination should have a major impact on the rate and mode of pollen evolution, and should also affect DNA sequence variation. 

This is a very large and collaborative project that relies on the unique and complementary skills of all the involved PIs. I am immensely grateful for the funding from the Knut and Alice Wallenberg Foundation, which makes it possible to take on such a large and ambitious project. As an evolutionary geneticist, I am very motivated by the prospects of testing fundamental evolutionary hypotheses on pollen evolution, but I also hope that the project will result in new and widely useful tools for pollen image analysis, comparative analyses, and new genomic resources for non-model plant systems suitable for addressing these questions, explains Slotte.

New technological advancements allow large amount of pollen data to be collected and compared

For the very first time, a large amount of data on pollen will be collected and compared in an effort to better understand how major evolutionary shifts between insect- and wind-pollination affect the genetics of the plant kingdom. This is now possible thanks to a combination of machine learning, computer vision, and large-scale DNA sequencing.

Thanks to the unique combination of competences among the applicants, we are in a position to generate and efficiently analyse large amounts of pollen image data, test hypotheses in a comparative phylogenetic framework, and finally investigate the impact of dilution effects at the genomic level.

Largest project funding in the department’s history

Tanja Slotte and co-applicants John Fitzpatrick, Allison Hsiang, and Catarina Rydin will receive 31 MSEK over five years. This is the largest funding a research project has received since the Department of Ecology, Environment and Plant sciences was founded in 2013. Head of Department Kristoffer Hylander underlines the importance of receiving this type of funding:

This type of large project will not only produce state-of-the-art research results, but it will also enable the department to recruit skilled new personnel who will enhance the overall research environment. I want to emphasize that this project exemplifies the success that can come from collaborating in a group with complementary skills to tackle new scientific challenges. I extend my heartfelt congratulations to Tanja Slotte and her team and wish them a strong start to the project!

On behalf of the department, we would like to extend our congratulations to Tanja, John, Allison, and Catarina on this well-deserved achievement. We wish you the best of luck with your project, and look forward to sharing your results!