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ARU pioneering mountain range-expanding project

26 July 2021 | Story Nonsindiso Qwabe | Photo Nonsindiso Qwabe

ARU Read more web — On top of the Drakensberg. The ARU and Witsieshoek Mountain Lodge research team are, from the left: Grant Martin, Dr Ralph Clark, Jan van Niekerk, Prof Aliza le Roux, Prof Peter Taylor, and Dr Sandy Steenhuisen.

All mountains around the world have native and non-native species that are expanding their ranges quite dramatically; however, little research has been conducted towards understanding the long-term redistribution of species and the effects of global change on biodiversity.

The Afromontane Research Unit (ARU) on the University of the Free State Qwaqwa Campus – as part of the Mountain Invasion Research Network – has secured a two-year EU Horizon 2020 project under the Department of Science and Innovation, which will be looking at the mechanisms underlying the success and impact of range-expanding species on biodiversity and ecosystem functioning.

On Monday 19 July 2021, the ARU took a few of its researchers on a scenic helicopter ride to the summit of the Drakensberg for an alpine field-experiment site inspection of the Mont-aux-Sources peak, one of the highest sections of the Drakensberg range. This site has been identified for the project which the research unit will be leading on mountain research.

ARU Director, Dr Ralph Clark, said the project would explore the effects of global change, biological invasions (when species invade new geographic regions), as well as climate and land-use change. He said experiments were needed to explore the various possibilities and to test the extent to which species respond to experimental treatments. The project would therefore be conducting experiments for two years using open-top chambers – causing an increase in temperature of 3 or 4 degrees to what you find naturally – on plant species from lower down to the top of the mountain, to see how they function. “This will give us an idea of whether they will be able to survive in global warming scenarios. If temperatures get warmer, we might start seeing a lot of plants up here that we wouldn’t otherwise find here.”

Dr Clark said little is known about the long-term monitoring of species distribution and the effects of global change. Implementing the project in the Maloti-Drakensberg alpine area will therefore put the area in the global mountain research arena. The elevational gradient in the Maloti-Drakensberg Mountains provides space to explore the key processes underlying the variation in species elevation with climate change. “One of the things we don’t know much about are alpine systems. We are hoping to establish a long-term alpine research site and try to add as many studies as we can. The more science we can bring up here, the more we can know about mountain life. What happens on mountains has a lot of impact on social dynamics.

“This project is looking to see what is driving range expansion. Every mountain has its own context. In the Swiss alpine, fires are not a big factor, but fires are one of the biggest factors on our mountains. Some of our native and non-native species are therefore fire-driven, so as fire increases, you might have them spreading faster.”

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UFS study on cell development in top international science journal

2008-09-16

A study from the University of the Free State (UFS) on how the change in the packaging of DNA with cell development influenced the expression of genes, will be published in this week’s early edition of the prestigious international, peer-reviewed science journal, the Proceeding of the National Academy of Sciences of the USA (PNAS).

The PNAS journal has an impact factor of 10, which means that studies published in the journal are, on average, referred to by ten other scientific studies in a two year period. The South African Journal of Science, by comparison, has an impact factor of 0.7.

The UFS study, funded by the Wellcome Trust and the National Research Foundation (NRF), looked at how the change in the packaging of DNA with cell development influenced the expression of genes. It is very relevant to research on stem cells, an area of medicine that studies the possible use of undifferentiated cells to replace damaged tissue.

Prof. Hugh Patterton, of the Department of Microbial, Biochemical and Food Biotechnology at the UFS, who led the study, said: "We are extremely proud of this study. It was conceived in South Africa, it was performed in South Africa, the data were analysed in South Africa, and it was published from South Africa."

When a gene is expressed, the information encoded in the gene is used to manufacture a specific protein. In eukaryotes, which include humans, there is approximately 1m of DNA, containing the genes, in every cell. This length of DNA has to fit into a cell nucleus with a diameter of only about 10 micrometer. In order to fit the DNA into such a small volume, eukaryotic cells wrap their DNA onto successive protein balls, termed nucleosomes. Strings of nucleosomes, resembling a bead of pearls, is folded into a helix to form a chromatin fiber. The study from the UFS investigated how the binding of a specific protein, termed a linker histone, that binds to the length of DNA between nucleosomes, influenced the formation of the chromatin fiber and also the activity of genes.

"We found that the linker histone bound to chromatin in yeast, which we use as a model eukaryote, under conditions where virtually all the genes in the organism were inactive. It was widely believed that the binding of the linker histone caused the inactivation of genes. We studied the relationship between the amount of linker histone bound in the vicinity of each gene and the expression of that gene for all the genes in yeast, using genomic techniques. We made the surprising discovery that even through the linker histone preferentially bound to genes under conditions where the genes were shut off, this inactivation of genes was not caused by the binding of the linker histone and folding of the chromatin,” said Prof. Patterton.

He said: “Instead our data strongly suggested that the observed anti-correlation was due to the movement of enzymes along the DNA molecule, involved in processing the information in genes for the eventual manufacture of proteins. This movement of enzymes displaced the linker histones from the DNA. This finding now requires a rethink on aspects of how packaging of DNA influences gene activity."

Prof. Patterton said that his research group, using the Facility for Genomics and Proteomics as well as the Bioinformatics Node at the UFS, was currently busy with follow-up studies to understand how other proteins in nucleosomes affected the activities of genes, as well as with projects to understand how chemicals found in red wine and in green tea extended lifespan. "We are certainly having a marvelous time trying to understand the fundamental mechanisms of life, and the UFS is an exciting place to be if one was interested in studying life at the level of molecules," he said.

Media Release
Issued by: Lacea Loader
Assistant Director: Media Liaison
Tel: 051 401 2584
Cell: 083 645 2454
E-mail: loaderl.stg@ufs.ac.za
18 September 2008

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