mRNA adenosine methylase (MTA) deposits m6A on pri-miRNAs to modulate miRNA biogenesis inArabidopsis thaliana
Regulation of gene expression is a crucial cellular function that is necessary for sustenance of life. Epigenetic modifications and miRNA based post-transcriptional gene regulation are among the various methods that cells employ to regulate gene expression. Our work provides evidence that m6A methylation (an epigenetic modification) plays a role in biogenesis of miRNAs, thus inter-connecting these two processes. In our research, we focus on how m6A methylation affects miRNA biogenesis in Arabidopsis thaliana. In brief, we show that m6A methylation is necessary to maintain proper levels of mature miRNAs as well as their precursors. m6A mark affects secondary structures of miRNA precursors and affects the recruitment of Microprocessor (enzymatic complex responsible for production of miRNAs from their precursors) to these precursors. We also demonstrate the interactions of MTA (m6A writer) with other proteins involved in miRNA biogenesis namely RNA Polymerase II and TOUGH. In plants, hormonal signaling plays an important role in their response to different environmental stimuli. We show that m6A methylation also plays a role in modulating auxin signaling via a miRNA (miRNA393b). In conclusion, we provide evidence that m6A methylation modulates biogenesis of miRNAs and in doing so also regulates other metabolic pathways like auxin signaling.
Susheel Sagar Bhat, Dawid Bielewicz, Tomasz Gulanicz, Zsuzsanna Bodi, Xiang Yu, Stephen J. Anderson, Lukasz Szewc, Mateusz Bajczyk, Jakub Dolata, Natalia Grzelak, Dariusz J. Smolinski, Brian D. Gregory, Rupert G. Fray, Artur Jarmolowski and Zofia Szweykowska-Kulinska
Proc. Natl. Acad. Sci. USA, 2020 DOI/10.1073/pnas2003733117
Glaciers are alive and constitute uniqe biodiversity hotspots
Glaciers are often seen as a lifeless element of the environment, simply supplying water and nutrients to neighbouring ecosystems. This prevailing view is, however, erroneous: glaciers are the coldest biome teeming with various cold-loving life forms, and biological processes occurring on glaciers are not only of local but also of global importance. The glacier biodiversity hotspots are centred on small ponds called cryoconite holes, thriving with unique species of algae, bacteria, fungi, protozoa and even animals such as tardigrades and rotifers. Glaciers are also one of the fastest disappearing ecosystems, yet still awaiting to be well explored. If you wonder why life on glaciers – although microscopic – is extremely important, read the paper by Krzysztof Zawierucha from the Department of Animal Taxonomy and Ecology and his colleagues, recently published in Nature Ecology & Evolution.
Stibal, M., Bradley, J.A., Edwards, A., Hotaling, S., Zawierucha, K., Rosvold, J., Lutz, S., Cameron, K.A., Mikucki, J.A., Kohler, T.J., Šabacká, M., Anesio, A.M. 2020. Glacial ecosystems are essential to understanding biodiversity responses to glacier retreat. Nature Ecology and Evolution, 4:686–687. DOI: 10.1038/s41559-020-1163-0
Recombination facilitates evolution of invasive parasites
Genomic analyses reveal adaptive evolution of the fish ectoparasite, Gyrodactylus bullatarudis that is shaped by the combination of gene duplications, divergence and recombination. In a paper by Konczal et al. published in Molecular Ecology, we describe reference genome of G. bullatarudis the authors compare it with other Platyhelminthes. Results suggest that duplications in several gene families, including G-proteins and serine proteases, are important in co-evolution between Gyrodactylus and their host, Trinidadian guppies. By comparing genomes from different populations the authors demonstrate a recent spread of the recombinant between two divergent genomes, showing that hybridization facilitates evolution of very successful parasites.
Konczal, M., Przesmycka, K. J., Mohammed, R. S., Phillips, K. P., Camara, F., Chmielewski, S., Hahn, C., Guigo, R., Cable, L., & Radwan, J. (2020).. Molecular Ecology. https://doi.org/10.1111/mec.15421
Evolution of extraordinary diversity of immunity genes – MHC.
Advances in the Evolutionary Understanding of MHC Polymorphism https://doi.org/10.1016/j.tig.2020.01.008
Jacek Radwan (Evolutionary Biology Group: http://evobio.home.amu.edu.pl/) and colleagues have published a paper in Trends in Genetics in which they review evolutionary mechanisms explaining landmark features of major histocompatibility complex (MHC) genes, including their extreme polymorphism, and identify open questions in MHC evolution research. Open access!
Low anthropopression has a good influence on peatlands’ hydrological regime
Scientists from the Laboratory of Climate Change Ecology studied long-term environmental changes of the small Sphagnum-dominated peatland Jaczno in north-eastern Poland. The aim of the project was to reconstruct vegetation changes, hydrological changes and anthropopression over the last 1500 years. The study revealed that the location of the peatland far from settlements and the strict protection of the area over the last several hundreds of years positively influenced the ecological and hydrological state of the Jaczno bog. Even though most of the peatlands in Europe are degraded by humans because of drainage or peat extraction, finding that Jaczno bog remained wet up to present times is extraordinary at the European scale. Our findings show how important it is to protect wetlands because these ecosystems are crucial for fighting climate change.
Marcisz, K., Kołaczek, P., Gałka, M., Diaconu, A.-C., and Lamentowicz, M. (2020). Exceptional hydrological stability of a Sphagnum-dominated peatland over the late Holocene. Quaternary Science Reviews 231, 106180. doi: https://doi.org/10.1016/j.quascirev.2020.106180.
Biometeorological conditions during heat waves in Poland
The observed climate change is manifested in increasingly frequent occurrence of heat waves. This has been acknowledged by Arek Tomczyk from the Department of Meteorology and Climatology with co-authors, who proved the pronounced increase of the persistent high-temperature periods in Poland since the beginning of the 21 century. Authors parametrized biometeorological conditions prevailing during heat waves. The most strenuous conditions were recorded in western and southwestern Poland, where days with strong and extreme heat stress conditions appeared the most frequently.
Tomczyk A.M., Bednorz E., Matzarakis A., 2020. Human-biometeorological conditions during heat waves in Poland. International Journal of Climatology, https://doi.org/10.1002/joc.6503
Reconstruction of river planform changes in loess areas
Despite turning many river courses into artificial canals, the record of the evolution of past fluvial landscapes is still preserved in the subsurface of the modern valleys. The first results describing river planform changes in loess landscape of Transdanubia (south Hungary) have been published in Global and Planetary Change. This research work reveals the history of the Kapos and Koppány Rivers during the last 14000 years, with periods of meander cutoffs in the Late Glacial, and flow discontinuation turning the river courses into wetlands during the last 4000 years. We show the identified fluvial forms and processes against a background of a conceptual model of meanders evolution in various hydrological and geological settings.
Słowik M., Dezső J., Kovác J., Gałka M., 2020, The formation of low-energy meanders in loess landscapes (Transdanubia, central Europe). Global and Planetary Change, 184, 103071https://doi.org/10.1016/j.gloplacha.2019.103071