To date most research into what drives the composition of ecosystems has focused on macroevolution, factors such as extinction events, invasion of new species, or large shifts in population abundances. A study in Nature Communications now shows that microevolution — small changes within a single population — is an equally important yet hitherto overlooked shaper of multi-species communities.
Bacteria secrete small molecules for purposes that range from communication to self-defense. These processes are extremely challenging to study in situ because it is nearly impossible to link secreted molecules to specific populations of bacteria let alone individual cells in their natural environment. By combining mass spectrometry-based imaging with fluorescence in situ hybridization (FISH) scientists at the Max Planck Institute for Chemical Ecology are able to image secretion patterns of antibiotics and map them onto the FISH profile of the bacterial population that underlies it.
Bacteriophages target bacteria with high specificity, a feature that has been exploited for biotechnology and therapeutics. That same exquisite specificity has, however, also been limiting — identifying or engineering phages with new specificities is often a prohibitively time consuming and laborious process. Scientists at MIT have now developed a yeast-based phage-engineering platform that overcomes these hurdles.
Whether you are using PCR to clone, assess gene expression, or diagnose disease, modern science is difficult to imagine without PCR. Scientists at UC Berkeley have rethought how we heat and cool samples during PCR, shortening a process that once took hours to minutes.
It is generally accepted that changes to a cell’s genome are driven by random mutation. Changes that confer a growth advantage become established in a population through the process of natural selection. A study published in PNAS suggests that cells can play a more active role in the evolution of their genomes — in response to caloric excess the TOR pathway in budding yeast initiates an expansion of the number of ribosomal genes.
An eye-like structure called the ocelloid, found in warnowiid dinoflagellates, has long puzzled biologists. This structure resembles the eye of higher organisms to such a degree, that is was first assumed to be part of an animal the warnowiid had eaten. Now this small eukaryotic plankton has surprised scientists again – the warnowiid eye’s building blocks are mitochondria and plastids.
The social amoeba Dictyostelium discoideum has two life stages. When nutrients are plentiful, Dicty live as individuals but when starvation sets in, thousands of Dicty come together to form a fruiting body. This fruiting body is made up of a stalk that holds up a ball of spores, and this is where the cheating comes in — only cells that make it to the top of the fruiting body and become a spore get to live and pass on their genetic information.