Marine Cyanobacteria Shed Billions of DNA-Containing Vesicles. Scientists have recently discovered and documented the first extracellular, DNA-containing vesicles shed by ocean microbes. The marine cyanobacteria – photosynthesizing, prokaryotic bacteria that are ubiquitous to most terrestrial and aquatic habitats – are involved in Earth’s biogeochemical and nutrient cycles. During photosynthesis, the bacteria harness sunlight to convert light energy into chemical energy, using carbon dioxide and water and releasing molecular oxygen as a byproduct.
Essentially, they provide a source of nourishment for other organisms, constituting an edible form of biomass. Scientists at the Massachusetts Institute of Technology (MIT) have discovered another potential role of cyanobacteria. They have confirmed that the bacteria manufacture and release tiny spherical packages containing a host of substances, including genetic material – which can be transferred via horizontal gene transfer – and nutrients. Autofluorescence seen in synechococcus bacteria. Sources: Read Write Think » Thought place to Read and Write. Dragonflies keeping their eyes on the prize | The Scicurious Brain. One of the things I love most about science blogging is the opportunity to learn about entirely new things. Of course, we all have that opportunity on most days, but having to find something to blog about three times a week definitely keeps me on my toes. And what I learn can be so fascinating! Often it’s about barnacle sperm or the evo psych of romance novels, but there are other, safe for work kinds of fascination, too!
And today, my fascination is with dragonflies. These little guys are amazing. And my fascination with them grew even more as I read this paper. Gonzalez-Bellido et al. (Source) The authors recorded from the visual neurons of a large number of dragonflies as they were presented with prey moving across the visual field. These dragonflies have a set of neurons called small target movement detectors, which specifically detect the small and speedy movements of potential prey. Gonzalez-Bellido PT, Peng H, Yang J, Georgopoulos AP, & Olberg RM (2013). *Kidding! British scientists recreate the molecules that gave birth to life itself. By Nick Enoch Updated: 08:03 GMT, 27 January 2012 Organic chemists at the University of York have recreated a pair of simple sugars - threose and erythrose - in a process which could have occurred before the advent of life Scientists are one step closer to understanding the origin of life after making a breakthrough into how sugar molecules found in DNA are created.
Organic chemists at the University of York have recreated a pair of simple sugars - threose and erythrose - in a process which could have occurred before the advent of life. The team, led by Dr Paul Clarke, along with colleagues at the University of Nottingham, have made the first step towards showing how the basic building blocks of life developed. Every biological molecule has an ability to exist in a left-handed form or right-handed form. All sugars in biology are made up of the right-handed form of molecules and yet all the amino acids that make up the peptides and proteins are made up of the left-handed form. Before DNA, before RNA: Life in the hodge-podge world - life - 08 January 2012. Take note, DNA and RNA: it's not all about you. Life on Earth may have begun with a splash of TNA – a different kind of genetic material altogether.
Because RNA can do many things at once, those studying the origins of life have long thought that it was the first genetic material. But the discovery that a chemical relative called TNA can perform one of RNA's defining functions calls this into question. Instead, the very first forms of life may have used a mix of genetic materials. Today, most life bar some viruses uses DNA to store information, and RNA to execute the instructions encoded by that DNA. A key piece of evidence for this "RNA world" hypothesis is that RNA is a jack of all trades. Now it seems TNA might have been just as capable, although it is not found in nature today.
It differs from RNA and DNA in its sugar backbone: TNA uses threose where RNA uses ribose and DNA deoxyribose. The team took a library of TNAs and evolved them in the presence of a protein. No TNA world. Life Science Reference - Biology Online. 1756-3305-4-106. SciCentral: Gateway to the best science news sources.
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