Cell biology

Recently, we noted that John Sanford was speaking at NIH on human health and mutations. Philip Cunningham writes to mention a 2017 paper by Sanford and S. T. Cordova, Nylonase Genes and Proteins – Distribution, Conservation, and Possible Origins on whether the ba cteria that digest nylon evolved new genes: We began this work hoping to better understanding the various claims regarding the de novo origin of certain nylonase genes. The idea that nylonases would have arisen very recently, de novo, was based upon the widely-held assumption that nylonases would have been essentially non-existent prior to the artificial manufacture of nylon. This basic assumption would not be justified if there were any nylonlike polymers in nature, or if nylonase activity Read More ›

Of course, just now, one suspects that it is mainly the editors in Frisco who have pored over it. But now, Darwinian evolutionary biologist Jerry “Why Evolution Is True” Coyne  tells us,l Michael Behe, author of the intelligent-design (ID) creationist books Darwin’s Black Box and The Edge of Evolution, has a new book coming out next February, Darwin Devolves: The New Science about DNA that Challenges Evolution. (Let me point out here that the phrase “that challenges evolution” has an unclear antecedent, either the new science that challenges evolution—what he clearly means—or the DNA itself that challenges evolution. Bad title!) The construction that offends Dr. Coyne is a clause, not a phrase; however, why be picky and it will doubtless be Read More ›

Not by adding to it. Everyone seems to be talking about devolution (“reductive evolution”) these days. From ScienceDaily: “This is the first large genome project like this that actually looks at hundreds of different eukaryotic species, not different individuals or isolates of the same species,” says Chris Todd Hittinger, a UW-Madison genetics professor and one of the senior authors of the study. “Budding yeasts, despite their phenotypic similarity, are very different from one another genetically. They’re as different from one another as all animals or all plants are from one another.” Collecting such a deep pool of yeast types gave researchers enough information to use comparisons of the shifting genetics to redraw the budding yeast family tree into a dozen Read More ›

The mechanome is the underresearched “ the set of proteins or molecular entities that sense or respond to forces” within the cell (Allen Liu). Our earlier stab at the subject here at UD garnered 354 comments, so there’s no shortage of interest. The mechanome (and mechanobiology in general) plays a key role in research into artificial cells. Suzan Mazur is the author of The Paradigm Shifters: Overthrowing ‘the Hegemony of the Culture of Darwin’. Suzan Mazur talks to mechanical and biomedical engineer Allen Liu, one of the people best placed to offer some insights:   Suzan Mazur: The Liu Lab at the University of Michigan is particularly interested in the mechanobiology of the cell lipid membrane. Would you briefly describe your Read More ›

Whose triumph would create “catastrophic genomic instability”: Since Carnegie Institution’s Barbara McClintock received her Nobel Prize on her discovery of jumping genes in 1983, we have learned that almost half of our DNA is made up of jumping genes—called transposons. Given their ability of jumping around the genome in developing sperm and egg cells, their invasion triggers DNA damage and mutations. This often leads to animal sterility or even death, threatening species survival. The high abundance of jumping genes implies that organisms have survived millions, if not billions, of transposon invasions. However, little is known about where this adaptability comes from. Now, a team of Carnegie researchers has discovered that, upon jumping gene invasion, reproductive stem cells boost production of Read More ›

The researchers claim it is a first: … a new paper from a group at the University of Oxford is now raising some eyebrows for its claims of the successful entanglement of bacteria with photons—particles of light. Led by the quantum physicist Chiara Marletto and published in October in the Journal of Physics Communications, the study is an analysis of an experiment conducted in 2016 by David Coles from the University of Sheffield and his colleagues. In that experiment Coles and company sequestered several hundred photosynthetic green sulfur bacteria between two mirrors, progressively shrinking the gap between the mirrors down to a few hundred nanometers—less than the width of a human hair. By bouncing white light between the mirrors, the Read More ›

From ScienceDaily: A kill code is embedded in every cell in the body whose function may be to cause the self-destruction of cells that become cancerous, reports a new Northwestern Medicine study. As soon as the cell’s inner bodyguards sense it is mutating into cancer, they punch in the kill code to extinguish the mutating cell. The code is embedded in large protein-coding ribonucleic acids (RNAs) and in small RNAs, called microRNAs, which scientists estimate evolved more than 800 million years ago in part to protect the body from cancer. The toxic small RNA molecules also are triggered by chemotherapy, Northwestern scientists report. Cancer can’t adapt or become resistant to the toxic RNAs, making it a potentially bulletproof treatment if Read More ›

Hat tip: Philip Cunningham April 7, 2017

Steve Meyer, author of Darwin’s Doubt, is thought to be vindicated by a paper published in 2017, “Experimental test and refutation of a classic case of molecular adaptation in Drosophila melanogaster” (Nature Ecology and Evolution). The paper “begins with a perceptive statement about what ought to be required when establishing some genetic evolutionary pathway: Identifying the genetic basis for adaptive differences between species requires explicit tests of historical hypotheses concerning the effects of past changes in gene sequence on molecular function, organismal phenotype and fitness.” It proceeded to apply that approach to whether fruit flies became able to digest alcohol via natural selection acting on random mutation. Apparently, it didn’t: “Our experiments strongly refute the predictions of the adaptive ADH Read More ›

From ScienceDaily: The cells in a tissue are surrounded by a net-like structure called the extracellular matrix. To attach itself to the matrix the cells have receptor molecules on their surfaces, which control the assembly of large protein complexes inside them. These so-called adhesion complexes connect the outside to the cell interior and also signal to the cell about its immediate environment, which affects its properties and behaviour. Researchers at Karolinska Institutet have now discovered a new type of adhesion complex with a unique molecular composition that sets it apart from those already known about. The discovery has been made in collaboration with researchers in the UK. “It’s incredibly surprising that there’s a new cell structure left to discover in Read More ›

From ScienceDaily: Unicellular diatoms are able to adapt their behavior to different external stimuli based on an evaluation of their own needs. This was discovered by scientists of the Friedrich Schiller University and the Max Planck Institute for Chemical Ecology in Jena, Germany, together with partners from Belgium. The algae depend on nutrients in order to reproduce. However, they also need sexual mates which they find when they follow pheromone traces. In experiments, Seminavis robusta diatoms directed their orientation either towards nutrient sources or mating partners, depending on the degree of starvation and the need to mate. The tiny organisms demonstrated in fact a primitive form of behavioral biology. … “It is striking that even unicellular organisms that obviously lack Read More ›

Instead of looking for fossil at that age, the researchers looked for biomarkers: Rather than searching for conventional body fossils, the researchers have been tracking molecular signs of animal life, called biomarkers, as far back as 660-635 million years ago during the Neoproterozoic Era. In ancient rocks and oils from Oman, Siberia, and India, they found a steroid compound produced only by sponges, which are among the earliest forms of animal life. “Molecular fossils are important for tracking early animals since the first sponges were probably very small, did not contain a skeleton, and did not leave a well-preserved or easily recognizable body fossil record,” Zumberge said. “We have been looking for distinctive and stable biomarkers that indicate the existence of sponges Read More ›

From ScienceDaily: Biologists know a lot about how life works, but they are still figuring out the big questions of why life exists, why it takes various shapes and sizes, and how life is able to amazingly adapt to fill every nook and cranny on Earth. An interdisciplinary team of researchers at Arizona State University has discovered that the answers to these questions may lie in the ability of life to find a middle ground, balancing between robustness and adaptability. The results of their study have been recently published in Physical Review Letters. The research team, led by Bryan Daniels of the Center for Biosocial Complex Systems with direction from faculty member Sara Walker of the School of Earth and Read More ›

We thought “purposeful efficiency” was enough to get a researcher fired, but read on: From ScienceDaily: The steps cells take in response to challenges are more complex than previously thought, finds new research published in the journal eLIFE. The study investigates a system relevant to cancer, viral infection, and diabetes as well as Parkinson’s and Lou Gehrig’s disease, revealing many cases of “purposeful inefficiency” in cellular behavior. These new pathways might offer routes for understanding and perhaps even treating these diseases, the study’s scientists note. “Surprisingly, cells often take an approach that seems quite inefficient,” explains Christine Vogel, an associate professor at New York University’s Department of Biology and the study’s lead author. “However, discovering these unexpected routes helps us Read More ›

Researchers have found some of the oldest and slowest life forms on Earth: In a bid to hone in on the lower energy limits for life, Hans Røy at Aarhus University in Denmark probed the clays below the North Pacific gyre. Under the microscope, he found a community made up of bacteria and single-celled organisms called archaea in vanishingly small numbers. “There are only 1000 tiny cells in 1 cubic centimetre of sediment, so finding just one is literally like hunting for a needle in a haystack.” The microbes rely on oxygen, carbon and other nutrients in their deep environment to live, but Røy’s team found that carbon is so limited that the cells respire oxygen 10,000 times slower than bacteria Read More ›