NEW FINDINGS — MICRO GENOMICS
Big Data Look at a Tiny Creature Tardigrades are tiny animals often called water bears. They are known for their ability to survive in extreme environments, thriving in extremely hot temperatures, high pressures, and radiation levels more than 1,000 times what would be fatal to humans. How they survive in these inhospitable environments has long been a mystery. Previously, scientists discovered that tardigrades enter a dormant state during harsh conditions by expelling most of their body's water, drastically slowing metabolism, and forming a protective, glass-like cocoon of proteins around their cells. However, this adaptation alone does not fully account for their remarkable radiation resistance. In 2024, researchers gathered genomic, transcriptomic, and proteomic data from tardigrades before and after doses of radi- ation. From this rich data set, they discovered that some of the water bears in the study were a previously unidentified species. Scientists also found 2,801 genes with different expression lev- els after radiation exposure. Several of the upregulated genes were found to play a role in surviving high radiation.
One gene induces the production of betalains, a radiation-blocking pigment found in bacteria and some plants. Other genes appear to increase the speed and efficiency of DNA repair mechanisms by phase sepa- ration. Upon detecting DNA damage, specifically double-stranded breaks,
Unique Cell Division in Mouth Bacteria Most bacteria reproduce through binary fission, a process where a single cell divides into two identical daughter cells. However, a common oral bacterium uses a different mechanism. Corynebacteri- um matruchotii , often found along the gum line, are long filamentous cells capable of splitting into as many as 14 daughter cells simultaneously. This remarkable process, called simultaneous multiple fission, sets C. matruchotii apart. While other bacteria can divide into multiple cells at once, they typically do so only under unfavorable conditions, forming dormant spores that later activate when the environment improves. In contrast, C. matruchotii produces active cells immediately, making the first documented case of this reproductive strategy. Researchers discovered this unique proteins form a liquid-like hydrocarbon complex that stabilizes the broken DNA strands, recruiting repair proteins to facilitate efficient restoration. These genes are believed to result from horizontal gene transfer from bacteria, providing a fascinating glimpse into the evolutionary adaptations that enable tardigrades to withstand conditions that would be lethal to most other organisms. n REFERENCE: Li L, et. al., Multi-omics landscape and molecular basis of radiation tolerance in a tardigrade. Science . 2024 Oct 25;386(6720):eadl0799. Epub 2024 Oct 25. PMID: 39446960. https://doi.org/10.1126/science.adl0799
Invisible Ecosystem in Your Bathroom
You don’t need to travel to the tropics to witness extraordinary biodiversity; just take a step into your bathroom. New research from microbiolo- gists at Northwestern University has revealed a rich and diverse viral ecosystem thriving on
everyday bathroom items like showerheads and toothbrushes. By analyzing the surfaces of 34 toothbrushes and 92 showerheads, the study uncovered over 600 unique viral sequences, revealing a hidden microbial world flourishing in human-made environments. The vast majority of these viruses are bacteriophages, which target bacteria rather than humans and play a significant role in shap- ing microbial communities. Notably, 532 of the sequences correspond to bacteriophages known to infect 32 bacterial families. The discovery of additional sequences that don't match any known organisms under- scores the need for further exploration of these microbial ecosystems. This study offers new insights into the dynamic and intricate world of microbes that inhabit our daily spaces. Interestingly, data suggest minimal interaction between the microbial communities of toothbrush- es and showerheads, even within the same bathroom. More research is necessary to develop larger datasets on the microbial composition of various human-made environments. Understanding how these ecosystems evolve over time and in different conditions will help scientists understand the role of viral biodiversity in maintaining the delicate balance of beneficial and harmful bacteria in our homes. This research marks a significant step toward leveraging genomic technol- ogies to explore the fascinating microscopic world that lives on and around us every day and its implications for both environmental and human health. n
phenomenon using time-lapse imaging to study the formation of biofilms. Biofilms are complex communities of microorganisms that attach to surfaces, such as teeth, and play a crucial role in oral health. The ability of C. matruchotii to rapidly produce multiple daughter cells may explain how it can quickly recolonize the tooth surface after brushing. This discovery has significant implications for understanding bacterial growth and biofilm dynamics in the mouth. It also
raises intriguing questions: could other bacteria exhibit similar behaviors, and how might this influence strategies for targeting biofilms more effectively? This insight into C. matruchotii ’s reproduc- tive strategy could pave the way for new approaches to managing oral hygiene and combating biofilm-related challenges. n REFERENCE: S. Chimileski, et al., Tip extension and simultaneous multiple fission in a filamentous bacterium, Proc. Natl. Acad. Sci. U.S.A. 121 (37) e2408654121, https://doi.org/10.1073/pnas.2408654121
REFERENCE: Huttelmaier, S., et al., (2024). Phage communities in household-related biofilms correlate with bacterial hosts. Frontiers in Microbiomes , 3, 1396560. https://doi.org/10.3389/frmbi.2024.1396560
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