Jan Andersson lab
The majority of the eukaryotic diversity is microbial. We are using comparative genomics methods to study these organisms. We are especially interested in evolutionary processes affecting the genomes of diplomonads (e.g. Giardia and Spironucleus) ads and how these relate to the phenotypic diversity in this fascinating group of organisms.
Popular science presentation
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 are determine 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. 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. Our studies of the genome sequences also show that a rapid evolution of gene families also contributes to specializations within the group. There are strong indications that diplomonads undergo genetic exchange via rare sexual recombination. Thanks to our research diplomonads are now one of the more well-studied groups of eukaryotic microbes.
Research projects
Diplomonads is a group of eukaryotes that strives in oxygen-poor environments that have gained attention because of their pathogenicity, basic cell structure and evolutionary peculiarities. For example, most diplomonads have two transcriptionally active nuclei and no sexual cycle have been observed although there are various signs of recombination. Most research has previously been focused on a single species, Giardia intestinalis, which is an important human intestinal pathogen.
We are currently targeting several diplomonad species found in different niches (free-living, commensals and pathogens). This research is performed in a larger group which is using a wide array of methods, ranging from experimental fish infections to advanced phylogenetic methods. The aim is to gain insight into different aspects of the cell biology, pathogenicity and evolution of various diplomonads.
Within our group we mainly focus on evolutionary aspects of diplomonad biology. We use bioinformatic tools, such as assembly, annotation and phylogenetics, to address evolutionary questions such as:
- adaptation of diplomonad lineages to increasing oxygen-levels during the evolution to pathogenic lifestyles
- secondarily adaptation to a free-living lifestyle by diplomonads such as Trepomonas and Hexamita
- genome structure evolution and the relationship to sexual or parasexual life cycles
Group members
Publications
A chromosome-scale reference genome for Spironucleus salmonicida
Part of Scientific Data, 2022
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
Comparative cell biology and evolution of Annexins in Diplomonads
Part of mSphere, 2016
Part of BMC Biology, 2016
Comparative genomic analyses of freshly isolated Giardia intestinalis assemblage A isolates
Part of BMC Genomics, 2015
Part of PLOS Genetics, 2014
Hydrogenosomes in the diplomonad Spironucleus salmonicida
Part of Nature Communications, p. 2493, 2013
Part of PLOS Neglected Tropical Diseases, 2012
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 Journal of Molecular Biology and Biotechnology, p. 83-95, 2011
Part of PLoS Neglected Tropical Diseases, 2011
From mouse to moose: multilocus genotyping of Giardia isolates from various animal species.
Part of Veterinary parasitology, p. 231-239, 2010
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
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
Gene transfers from nanoarchaeota to an ancestor of diplomonads and parabasalids.
Part of Mol Biol Evol, p. 85-90, 2005
Lateral gene transfer in eukaryotes.
Part of Cell Mol Life Sci, p. 1182-97, 2005
Evidence for cryptic Golgi in putatively ‘Golgi-lacking’ lineages
Part of Proceedings of the Royal Society of London. Biological Sciences, 2003
Part of BMC Evolutionary Biology, p. 14, 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
Part of Eukaryotic Cell, p. 304-310, 2002
Genomics. Are there bugs in our genome?
Part of Science, p. 1848-1850, 2001
Pseudogenes, junk DNA, and the dynamics of Rickettsia genomes
Part of Molecular biology and evolution, p. 829-839, 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
People
Jan Andersson, Associate professor