Jan Andersson
Senior Lecturer/Associate Professor at Department of Cell and Molecular Biology; Molecular Evolution
- Mobile phone:
- +46 70 167 95 98
- E-mail:
- jan.andersson@icm.uu.se
- Visiting address:
- Husargatan 3
752 37 UPPSALA - Postal address:
- Box 596
751 24 UPPSALA
- CV:
- Download CV
Short presentation
I am a senior lecturer in microbial evolutionary genomics. Since the early 10s, I have been heavily involved in teaching and teaching issues in the role of program director for the MSc program in molecular biotechnology engineering.
My research is about how changes in the genome facilitate evolutionary adaptations to new environments in eukaryotic microorganisms, a process for which I have contributed to the understanding that horizontal gene transfer from bacteria plays an important role.
Keywords
- microbiology
- molecular evolution
- comparative genomics
- lateral gene transfer
- horizontal gene transfer
- evolutionary genomics
- anaerobic protists
- diplomonads
- molekylär bioteknik
- programutveckling
- mikrobiologi
- horisontell genöverföring
Biography
I grew up in Björklinge, north of Uppsala, and began my university studies at Uppsala University in 1990. In the following years, I studied mathematics and natural sciences. I did a one year's military service and a six-month ERASMUS exchange to Sussex University in Brighton before I started my doctoral studies in the fall of 1995. I studied how intracellular bacteria of the genus Rickettsia evolved, with Siv Andersson and Charles Kurland as supervisors.
During my PhD, I was able to demonstrate that the genome contained genes that had lost their function, so-called pseudogenes. It was a phenomenon known to exist in eukaryotes at the time but many in the research field doubted that pseudogenes existed in bacteria. I also contributed to the genome sequence of Rickettsia prowazekii, which was the first complete genome published by a Swedish group, and the 18th in the world.
After the defense in December 1999, I was a postdoc for three years at Dalhousie University in Halifax, Nova Scotia, Canada with a Wennergren scholarship. Ford Doolittle and Andrew Roger were my supervisors. I studied the role of horizontal gene transfer between prokaryotes and eukaryotes in the evolution of microbial eukaryotes. It became clear early on to me, and my supervisors, that it was an important process that was largely neglected by the research field.
When I returned to Uppsala in 2003 as a Assistant professor, I continued the studies of genome evolution of protists, with a particular focus on the role of horizontal gene transfer. During the 00s, I published a series of papers that, along with studies from other groups, slowly built acceptance in the research field that horizontal gene transfer is an aspect of genome evolution that should not be ignored in studies of eukaryotic microorganisms.
Since the late 00s, the focus has shifted more towards the evolution of diplomonads, a group of eukaryotic microorganisms found in oxygen-poor environments. We study Giardia lamblia, which causes diarrhea in humans, but also the fish parasite Spironucleus salmonicida and the free-living Trepomonas and Hexamita inflata. Questions we studied include e.g. whether different isolates of Giardia are different species, how the defense against oxygen and oxygen radicals has evolved in diplomonads and their relatives and how the secondarily free-living diplomonads have been able to adapt to a life independent of a host organism.
Since the 10th century, I have been heavily involved in teaching and program development. I have worked a lot with project courses in addition to teaching traditional courses in bioinformatics and molecular biology. In these courses, I have developed structures to involve external actors from industry and authorities as clients of projects.
I was program director for the MSc program in Molecular biotechnology engineering during 2013-2021. During that time I, together with the program council and departments, reviewed and restructured the entire program with the aim of strengthening the progression, the achievement of program goals and the matching with the industry. The work resulted in a mandatory block of courses in years 1-3 followed by three different profiles in years 4 and 5 during which the students can select their individual specialisation. Together with IBG and the program council, I introduced an ethics track that runs through the entire program. Since 2022, I am deputy program
Research
The overall goal of our research is to understand how different evolutionary processes acting on the genomic level have changed, and still are changing, the biology of microbial eukaryotes. We focus on diplomonads, a peculiar group with the genetic material divided into two separate nuclei in the cell. Knowledge from our research gives a deeper understanding of the origin and evolution of parasites, and the role of eukaryotic microbes in natural environments.
I am using a diplomonads, a group of microorganisms as a model since many years. We are using sequencing technology to do whole genome sequencing of different diplomonads. Using bioinformatic tools we identify differences and similarities within the group, as well as between diplomonads and other organisms. Then we are trying to couple differences in the genome to variations in the biology.
The group diplomonads both contains parasites which, for example, infect humans (e.g. Giardia lamblia) and fish (e.g. Spironucleus salmonicida), but also species that do not cause disease in the host, and free-living species such as Trepomonas and Hexamita inflata. We have shown that diplomonads have adapted to oxygen-poor environments by acquisition of genetic material from other organisms. We have also demonstrated the presence of hydrogenosomes, hydrogen-producing organelles, in some diplomonads and that the free-living diplomonads have evolved from organisms that were dependent on a host organism. Horizontal gene transfer from the bacteria taken up as food by the eukaryote has contributed to the adaptation to a life outside the host organism.

Publications
Selection of publications
Metabolic reconstruction elucidates the lifestyle of the last Diplomonadida common ancestor
Part of mSystems, 2020
Part of Genome Biology and Evolution, p. 2542-2556, 2019
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
- Download full text (pdf) of On the reversibility of parasitism: adaptation to a free-living lifestyle via gene acquisitions in the diplomonad Trepomonas sp PC1
Part of PLOS Genetics, 2014
- DOI for The genome of Spironucleus salmonicida highlights a fish pathogen adapted to fluctuating environments
- Download full text (pdf) of The genome of Spironucleus salmonicida highlights a fish pathogen adapted to fluctuating environments
Double peaks reveal rare diplomonad sex
Part of Trends in Parasitology, p. 46-52, 2012
Part of Molecular biology and evolution, p. 2895-2898, 2012
Part of PLoS Pathogens, 2009
Gene Transfer and Diversification of Microbial Eukaryotes
Part of Annual Review of Microbiology, p. 177-193, 2009
Lateral gene transfer in eukaryotes.
Part of Cell Mol Life Sci, p. 1182-97, 2005
Part of Current Biology, p. 94-104, 2003
Pseudogenes, junk DNA, and the dynamics of Rickettsia genomes
Part of Molecular biology and evolution, p. 829-839, 2001
The genome sequence of Rickettsia prowazekii and the origin of mitochondria
Part of Nature, p. 133-140, 1998
Recent 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
- Download full text (pdf) of The expanded genome of Hexamita inflata, a free-living diplomonad
A chromosome-scale reference genome for Spironucleus salmonicida
Part of Scientific Data, 2022
- DOI for A chromosome-scale reference genome for Spironucleus salmonicida
- Download full text (pdf) of A chromosome-scale reference genome for Spironucleus salmonicida
Metabolic reconstruction elucidates the lifestyle of the last Diplomonadida common ancestor
Part of mSystems, 2020
Part of Microbial Genomics, 2020
Part of Genome Biology and Evolution, p. 2542-2556, 2019
All publications
Articles in journal
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
- Download full text (pdf) of The expanded genome of Hexamita inflata, a free-living diplomonad
A chromosome-scale reference genome for Spironucleus salmonicida
Part of Scientific Data, 2022
- DOI for A chromosome-scale reference genome for Spironucleus salmonicida
- Download full text (pdf) of A chromosome-scale reference genome for Spironucleus salmonicida
Metabolic reconstruction elucidates the lifestyle of the last Diplomonadida common ancestor
Part of mSystems, 2020
Part of Microbial Genomics, 2020
Part of Genome Biology and Evolution, p. 2542-2556, 2019
Organelles that illuminate the origins of Trichomonas hydrogenosomes and Giardia mitosomes
Part of NATURE ECOLOGY & EVOLUTION, 2017
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
- Download full text (pdf) of On the reversibility of parasitism: adaptation to a free-living lifestyle via gene acquisitions in the diplomonad Trepomonas sp PC1
Comparative cell biology and evolution of Annexins in Diplomonads
Part of mSphere, 2016
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
- Download full text (pdf) of Comparative genomic analyses of freshly isolated Giardia intestinalis assemblage A isolates
Part of PLOS Genetics, 2014
- DOI for The genome of Spironucleus salmonicida highlights a fish pathogen adapted to fluctuating environments
- Download full text (pdf) of The genome of Spironucleus salmonicida highlights a fish pathogen adapted to fluctuating environments
Hydrogenosomes in the diplomonad Spironucleus salmonicida
Part of Nature Communications, p. 2493, 2013
Part of PLOS Neglected Tropical Diseases, 2012
- DOI for Common Coinfections of Giardia intestinalis and Helicobacter pylori in Non-Symptomatic Ugandan Children
- Download full text (pdf) of Common Coinfections of Giardia intestinalis and Helicobacter pylori in Non-Symptomatic Ugandan Children
Double peaks reveal rare diplomonad sex
Part of Trends in Parasitology, p. 46-52, 2012
Part of Molecular biology and evolution, p. 2895-2898, 2012
Phylogenomic approaches underestimate eukaryotic gene transfer
Part of Mobile Genetic Elements, p. 59-62, 2012
Part of PLoS Neglected Tropical Diseases, 2011
Part of Journal of Molecular Biology and Biotechnology, p. 83-95, 2011
Part of BMC Genomics, 2010
- DOI for Large genomic differences between the morphologically indistinguishable diplomonads Spironucleus barkhanus and Spironucleus salmonicida
- Download full text (pdf) of Large genomic differences between the morphologically indistinguishable diplomonads Spironucleus barkhanus and Spironucleus salmonicida
Genome analysis and comparative genomics of a Giardia intestinalis assemblage E isolate.
Part of BMC Genomics, p. 543, 2010
From mouse to moose: multilocus genotyping of Giardia isolates from various animal species.
Part of Veterinary parasitology, p. 231-239, 2010
Part of PLoS Pathogens, 2009
Horizontal gene transfer between microbial eukaryotes.
Part of Methods in Molecular Biology, p. 473-487, 2009
Dominance of Giardia assemblage B in León, Nicaragua.
Part of Acta Tropica, p. 44-53, 2008
Part of Gene, p. 1-8, 2008
Part of International Journal of Parasitology, p. 935-944, 2008
Part of BMC Evolutionary Biology, 2006
- DOI for Evolution of four gene families with patchy phylogenetic distributions: influx of genes into protist genomes
- Download full text (pdf) of Evolution of four gene families with patchy phylogenetic distributions: influx of genes into protist genomes
Lateral gene transfer in eukaryotes.
Part of Cell Mol Life Sci, p. 1182-97, 2005
Gene transfers from nanoarchaeota to an ancestor of diplomonads and parabasalids.
Part of Mol Biol Evol, p. 85-90, 2005
Part of BMC Evolutionary Biology, p. 14, 2003
Evidence for cryptic Golgi in putatively ‘Golgi-lacking’ lineages
Part of Proceedings of the Royal Society of London. Biological Sciences, 2003
How big is the iceberg of which organellar genes in nuclear genomes are but the tip?
Part of Philosophical Transactions of the Royal Society of London. Biological Sciences, p. 39-58; discussion 57, 2003
Part of Current Biology, p. 94-104, 2003
A cyanobacterial gene in nonphotosynthetic protists: an early chloroplast acquisition in eukaryotes?
Part of Current Biology, p. 115-119, 2002
Pseudogenes, junk DNA, and the dynamics of Rickettsia genomes
Part of Molecular biology and evolution, p. 829-839, 2001
Genomics. Are there bugs in our genome?
Part of Science, p. 1848-1850, 2001
A century of typhus, lice and Rickettsia
Part of Research in Microbiology, p. 143-150, 2000
Evolutionary genomics: is Buchnera a bacterium or an organelle?
Part of Current Biology, 2000
Genome degradation is an ongoing process in Rickettsia
Part of Molecular biology and evolution, p. 1178-1191, 1999
Insights into the evolutionary process of genome degradation
Part of Current Opinion in Genetics and Development, p. 664-671, 1999
The genome sequence of Rickettsia prowazekii and the origin of mitochondria
Part of Nature, p. 133-140, 1998
Part of Microbiology, p. 2783-2795, 1997
Articles, review/survey
Gene Transfer and Diversification of Microbial Eukaryotes
Part of Annual Review of Microbiology, p. 177-193, 2009
Part of BMC Genomics, p. 51, 2007
Convergent evolution: gene sharing by eukaryotic plant pathogens.
Part of Curr Biol, 2006
Chapters in book
Gene Transfer and the Chimeric Nature of Eukaryotic Genomes
Part of Lateral Gene Transfer in Evolution, p. 181-197, Springer Science+Business Media B.V., 2013
The genome of Giardia and other diplomonads
Part of Anaerobic Parasitic Protozoa: Genomics and Molecular Biology, p. 23-44, Caister Academic Press, 2010
Eukaryotic gene transfer: adaptation and replacements
Part of Horizontal Gene Transfer in the Evolution of Pathogenesis, p. 293-316, Cambridge University Press, 2008
Genome evolution of anaerobic protists: metabolic adaptation via gene acquisition.
Part of Genomics and Evolution of Microbial Eukaryotes, p. 109-122, Oxford University Press, Oxford., 2006
Bacterial DNA in the human genome
Part of Encyclopedia of the Human Genome, Nature Publishing Group; London; UK, 2003
Other
The New Foundations of Evolution: On the Tree of Life
Part of Systematic Biology, p. 114-115, 2011
A review of "Microbial Phylogeny and Evolution: Concepts and Controversies"
Part of Systematic Biology, p. 359-361, 2006