“As we are looking for new ways to drive biomedical innovations, evolution has already been creating various solutions to overcome complex challenges for millions of years. Wild animal species can reveal important biological mechanisms applicable for humans, but we must first unlock their molecular mysteries,” Kateryna Gaertner says.
Gaertner’s doctoral dissertation provided evidence that cells obtained from wild animals retain their molecular features and therefore are important sources for gaining deeper understanding of biological diversity, unique physiological traits and species-specific adaptations that can inform biomedical and ecological research.
“Maintaining health and adapting to stress depend on how efficiently mitochondria functions, and how well genes from both the mitochondria and the cell’s nucleus cooperate”, Gaertner explains.
Gaertner’s research was largely focused on deciphering and comparing mitochondrial bioenergetic and temperature producing functions. Gaertner’s findings revealed that mountain hare cells physiologically maintain elevated mitochondrial membrane potential and colder mitochondrial temperature accompanied with activated glycerol-3-phosphate and creatine metabolism. These two metabolic pathways are known for their role in supporting energy storage and thermogenesis, but their activity in skin fibroblasts – the type of cells used in the study – has not been characterized before.
Furthermore, Gaertner’s research provided the first evidence that the mitochondrial temperature, under physiological conditions, varies between closely related yet ecologically distinct species – a discovery that could have far-reaching implications for understanding animal adaptation to climate change and the role of mitochondria in human health.
Better understanding of mitonuclear compatibility could enhance fertility therapies
Gaertner based her work on the observation that mitochondrial transfer occurs as these two hare species naturally hybridize and obtained offsprings remain fertile, facilitating recurrent genetic flow across the species barrier. Using cytoplasmic hybrid cell models, in which mitochondria and nucleus were interchangeably transferred from one hare species to another, she investigated how novel mitonuclear gene combinations affect gene expression levels and cell physiology. From a medical standpoint, gaining a better understanding of mitonuclear compatibility could support the advancement of mitochondrial replacement and fertility therapies. Her analyses uncovered alterations in cellular fitness in particular genetic combinations, but also transcriptional changes linked to cybrid generation process itself, emphasising the need for caution as cybrid models are widely used to study human pathologies.
Taken together, Gaertner’s interdisciplinary research provides new perspectives on the complex functions of mitochondria in maintaining cellular health.
“With this work I wish to promote research that bridges across fields, sharing technological expertise that will expand our scientific toolbox by including previously overlooked species. Furthermore, I wish to advocate for using cell models to reduce the number of animals involved in research, and to highlight the importance of nature conservation strategies. Every species lost from its natural environment takes with it a piece of the scientific puzzle that we may never be able to replace”, Gaertner says.
Kateryna Gaertner is originally from Kyiv, Ukraine, where she completed her MSc degree in veterinary medicine and acquired qualification of a Veterinary Doctor. Later she obtained European MSc degree in Comparative Vertebrate Morphology (EUCOMOR), before moving to Finland to pursue her PhD and work in the Mitochondrial Bioenergetics and Metabolism research group at the Faculty of Medicine and Health Technology at Tampere University. Gaertner’s doctoral dissertation was conducted at Tampere University in Docent Eric Dufour’s Lab in collaboration with the University of Easter Finland and Professor Jaakko Pohjoismäki’s research group.
Public defence on Thursday 12 June
The doctoral dissertation of DVM, MSc Kateryna Gaertner in the field of life sciences titled Molecular Determinants of Speciation, Adaptation and Interspecies Compatibility: Lessons Learned from Cell Lines will be publicly examined at the Faculty of Medicine and Health Technology at Tampere University at 12 o’clock on Thursday 12 June 2025 at Kauppi campus, Arvo building, auditorium F114 (Arvo Ylpön katu 34, Tampere). The Opponent will be Professor Wendy R. Hood from Auburn University, USA. The Custos will be Docent Eric Dufour from the Faculty of Medicine and Health Technology.