Jerlström-Hultqvist lab

Symbioses between eukaryotes and prokaryotes have been crucial to major evolutionary transitions and have contributed to increased biodiversity. These partnerships have led to the development of specialized functions and organs in various multicellular organisms, such as nitrogen-fixing legumes, insects, deep-sea vent organisms, and light organs in aquatic animals. Bacterial and archaeal symbioses also occur in many unicellular protists. However, the foundations of symbiosis in protists, the extent of integration between host and symbiont, and the adaptations of host cells remain largely unexplored. The research groups aims to understand how these collaborations work and how they have evolved.
Popular science presentation
Our research aims to understand how new organelles form. We focus on an amoeba, Anaeramoeba, which has recently been isolated from oxygen-poor marine sediments. Anaeramoeba has a symbiotic relationship with a sulfate-reducing bacterium that lives close to the amoeba's hydrogenosome. The bacteria reside within the amoeba in a tubular network of narrow channels that connect them to the cell's exterior. Through these channels, the bacteria can absorb sulfate from seawater, even though they live inside the amoeba. How the membrane organelle that maintains this complex connection between Anaeramoeba and the bacteria has developed and been maintained over time is still unknown.
We use modern methods to investigate the symbiosis from multiple perspectives. With the latest sequencing technologies, we map the complete genome sequences of both the amoeba and its symbionts, allowing for in-depth studies of their evolutionary relationships. The close interaction between the amoeba and the symbiont is analyzed using fluorescence microscopy and high-resolution tomographic electron microscopy techniques.


Research
Collaborations between unrelated cells through symbiosis are widespread in nature. In most symbiotic relationships, cells exchange nutrients in a process known as syntrophy. Symbiosis has been studied for over a century and is fundamental to many processes essential for life. A notable example is the partnership between plants and nitrogen-fixing bacteria, which enables certain plants to thrive in nitrogen-deficient environments. Plants develop specialized structures, called symbiosomes, that facilitate interaction with these bacteria and reward them for their role.
While most studies on symbiotic organelles have focused on multicellular organisms, there is much less research on similar symbioses found in single-celled eukaryotes (protists) in oxygen-poor environments. Our research group explores the mechanisms that drive these symbioses and their evolutionary origins. We aim to uncover how new organelles emerge and the processes that regulate them.
Group members
Publications
The expanded genome of Hexamita inflata, a free-living diplomonad
Part of Scientific Data, 2025
- DOI for The expanded genome of Hexamita inflata, a free-living diplomonad
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A unique symbiosome in an anaerobic single-celled eukaryote
Part of Nature Communications, 2024
- DOI for A unique symbiosome in an anaerobic single-celled eukaryote
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Chromosome-level genome assembly and annotation of the social amoeba Dictyostelium firmibasis
Part of Scientific Data, 2024
- DOI for Chromosome-level genome assembly and annotation of the social amoeba Dictyostelium firmibasis
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Extreme mitochondrial reduction in a novel group of free-living metamonads
Part of Nature Communications, 2024
- DOI for Extreme mitochondrial reduction in a novel group of free-living metamonads
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Meteora sporadica, a protist with incredible cell architecture, is related to Hemimastigophora
Part of Current Biology, 2024
Part of Science Advances, 2024
- DOI for Nitrogen fixation in the widely distributed marine γ-proteobacterial diazotroph Candidatus Thalassolituus haligoni
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Ancient and pervasive expansion of adaptin-related vesicle coat machinery across Parabasalia
Part of International Journal of Parasitology, p. 233-245, 2023
Draft genomes of Blastocystis subtypes from human samples of Colombia
Part of Parasites & Vectors, 2023
- DOI for Draft genomes of Blastocystis subtypes from human samples of Colombia
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Massive intein content in Anaeramoeba reveals aspects of intein mobility in eukaryotes
Part of Proceedings of the National Academy of Sciences of the United States of America, 2023
- DOI for Massive intein content in Anaeramoeba reveals aspects of intein mobility in eukaryotes
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RNA interactome capture in Escherichia coli globally identifies RNA-binding proteins
Part of Nucleic Acids Research, p. 4572-4587, 2023
- DOI for RNA interactome capture in Escherichia coli globally identifies RNA-binding proteins
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Part of Genomics, 2022
- DOI for Comprehensive characterization of Cysteine-rich protein-coding genes of Giardia lamblia and their role during antigenic variation
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A Detailed Gene Expression Map of Giardia Encystation
Part of Genes, p. 1932, 2021
- DOI for A Detailed Gene Expression Map of Giardia Encystation
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Part of Current Biology, p. 5605-561200000, 2021
- DOI for Anaeramoebae are a divergent lineage of eukaryotes that shed light on the transition from anaerobic mitochondria to hydrogenosomes
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Part of Nature Communications, 2021
- DOI for Genomic analysis finds no evidence of canonical eukaryotic DNA processing complexes in a free-living protist
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Structure and mechanism of a phage-encoded SAM lyase revises catalytic function of enzyme family
Part of eLIFE, 2021
- DOI for Structure and mechanism of a phage-encoded SAM lyase revises catalytic function of enzyme family
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Evolution of a New Function by Fusion between Phage DNA and a Bacterial Gene
Part of Molecular biology and evolution, p. 1329-1341, 2020
- DOI for Evolution of a New Function by Fusion between Phage DNA and a Bacterial Gene
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Part of Microbial Genomics, 2020
Part of BMC Biology, 2019
- DOI for Oxygen induces the expression of invasion and stress response genes in the anaerobic salmon parasite Spironucleus salmonicida
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Proximity Staining using Enzymatic Protein Tagging in Diplomonads
Part of mSphere, 2019
- DOI for Proximity Staining using Enzymatic Protein Tagging in Diplomonads
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Part of Nature Ecology & Evolution, p. 1321-1330, 2018
Comparative cell biology and evolution of Annexins in Diplomonads
Part of mSphere, 2016
Part of BMC Biology, 2016
- DOI for On the reversibility of parasitism: adaptation to a free-living lifestyle via gene acquisitions in the diplomonad Trepomonas sp PC1
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Comparative genomic analyses of freshly isolated Giardia intestinalis assemblage A isolates
Part of BMC Genomics, 2015
- DOI for Comparative genomic analyses of freshly isolated Giardia intestinalis assemblage A isolates
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Part of PLOS Genetics, 2014
- DOI for The genome of Spironucleus salmonicida highlights a fish pathogen adapted to fluctuating environments
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Hydrogenosomes in the diplomonad Spironucleus salmonicida
Part of Nature Communications, p. 2493, 2013
Transcriptome Profiling of Giardia intestinalis Using Strand-specific RNAseq
Part of PloS Computational Biology, 2013
- DOI for Transcriptome Profiling of Giardia intestinalis Using Strand-specific RNAseq
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Part of Molecular biology and evolution, p. 2895-2898, 2012
Laboratory cryo soft X-ray microscopy
Part of Journal of Structural Biology, p. 267-272, 2012
Part of Eukaryotic Cell, p. 864-873, 2012
Stable transfection of the diplomonad parasite Spironucleus salmonicida
Part of Eukaryotic Cell, p. 1353-1361, 2012
Genome analysis and comparative genomics of a Giardia intestinalis assemblage E isolate.
Part of BMC Genomics, p. 543, 2010
Part of BMC Genomics, p. 258, 2010
Part of PLoS Pathogens, 2009
Spironucleus mitochondrial remnants suggest that hydrogenosomes are ancient organelles
Part of Proceedings of the National Academy of Sciences of the United States of America
Alumni
Oscar Åberg, former Master student
Ka Hei Lam, former Master student