An international team of researchers with a central contribution from researchers from the Dept. of Biological Physics at Eötvös Loránd University (ELTE) has unraveled the evolutionary origins of animals and fungi.
The findings, published in the journal Naturedemonstrate how genomic data and powerful computational methods enable scientists to answer fundamental questions in evolutionary biology that were previously unapproachable.
Scientists have always been curious about the evolutionary history of animals and fungi: These two groups of complex multicellular organisms are completely different at first glance, but in fact they are cousins on the tree of life. Animals and fungi are members of the same extended family, called a eukaryotic supergroup, and are much more closely related to each other than to plants. Understanding how such complex but contrasting groups evolved within the same eukaryotic supergroup has been challenging due to the lack of a detailed fossil record from the time the two groups diverged.
“To solve this evolutionary conundrum, we first had to produce genomic data of the unicellular groups that branch between animals and fungi in the tree of life,” said Iñaki Ruiz-Trillo, lead researcher and professor of Evolutionary Biology at the Institute of Evolutionary Biology in Barcelona and last author of the article.
Rather than relying on fossils, the authors reconstructed the evolution of the two groups based on the genetic information found in the genomes of fungi and animals living today. By combining the genomic data produced for these single-cell groups with genomic data from multiple species of animals and fungi, the researchers reconstructed the trajectory of genetic changes leading to the origin of these two eukaryotic groups using advanced computer models of genetic change.
“On a methodological level, there are two factors that have a huge impact in the field of evolutionary biology. One is that it is currently much easier to produce genomic data for any organism. The second is that our computers today can run much more complex evolutionary models to analyze this data,” said Gergely J Szöllősi, principal investigator in the ERC GENECLOCKS research group and assistant professor in ELTE’s Department of Biological Physics and co-author of the paper.
The global picture that emerged from the analyzes is that the genomic differences we see today between modern animals and fungi are the result of gradual changes that started early in evolution. The authors’ results indicate that this process began immediately after the divergence of the ancestors of the two groups more than a billion years ago.
“This surprised us because we expected most of the changes to have occurred specifically in association with animal and fungal origins. What we saw instead is the opposite, most of the changes in gene content occurred before the origins of the two groups,” said Eduard Ocaña-Pallarès, a postdoctoral researcher at ELTE University and first author.
According to the researchers, the lineage leading to animals began to accumulate genes that would later become essential for the multicellularity of animals. In contrast, the lineage that led to modern fungi experienced more genetic losses and the genetic content shifted toward metabolic functions. This shift allowed the fungi to adapt and survive in a bewildering variety of environments.
“Moving from Barcelona to Hungary and joining the ERC GENECLOCKS research group at ELTE was the best decision I could have ever made from a professional perspective. During my PhD in Barcelona we generated a lot of genomic data, but all this data is meaningless unless you analyze it with the right methods.I decided to continue this research in Gergely’s group because I knew they were developing advanced software for reconstructing the ancestral gene content.This decision was critical to the success of the project,” concluded Eduard Ocaña-Pallarès, postdoctoral researcher in ELTE’s Department of Biological Physics.
“This work is a great example of how collaboration around the world can drive science and lead to excellence in research,” adds Gergely J Szöllősi.
Strange and wonderful world of fungi formed by evolutionary eruptions, study finds
Iñaki Ruiz-Trillo, Divergent genomic trajectories predate the origin of animals and fungi, Nature (2022). DOI: 10.1038/s41586-022-05110-4. www.nature.com/articles/s41586-022-05110-4
Provided by Eötvös Loránd University
Quote: Reconstruction of Alternative Pathways to Complex Multicellularity in Animals and Fungi from Today’s Genetic Diversity (2022, Aug 24) retrieved Aug 24, 2022 from https://phys.org/news/2022-08-reconstructing-alternative-paths- complex multicellularity. html
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