Genomics

From ScienceDaily: Carrying around a spare tire is a good thing — you never know when you’ll get a flat. Turns out we’re all carrying around “spare tires” in our genomes, too. Today, in ACS Central Science, researchers report that an extra set of guanines (or “G”s) in our DNA may function just like a “spare” to help prevent many cancers from developing. More. The researchers scanned the sequences of known human oncogenes associated with cancer, and found that many contain the four G-stretches necessary for quadruplex formation and a fifth G-stretch one or more bases downstream. The team showed that these extra Gs could act like a “spare tire,” getting swapped in as needed to allow damage removal by Read More ›

We are told that the mistletoe species lacks genes found in all other complex organisms. From ScienceDaily: A discovery made during an analysis of a species of mistletoe whose apparent ability to survive without key genes involved in energy production could make it one of the most unusual plants on Earth. … “This loss of genes very likely corresponds to the loss of an entire respiratory complex,” said Jeff Palmer, IU Distinguished Professor in the IU Bloomington College of Arts and Sciences’ Department of Biology, who led the study. “This is something that hasn’t been reported before for any multicellular organism.” The genes that have been lost from V. scurruloideum typically reside in the mitochondrial genomes of plants and animals. Read More ›

From The Scientist : A large number of human genes can substitute for their defective counterparts in yeast and prevent the microorganisms from dying, according to a paper published today (May 21) in Science. Of more than 400 human-to-yeast gene replacements performed, almost 50 percent were effective at compensating for a missing vital function. “No one has carried out an evolutionary study of this kind before and certainly not of this scale,” said Nevan Krogan of the University of California, San Francisco, who was not involved in the work. “It’s rather satisfying to see that half of the genes could complement [the yeast function] because it justifies continuing working in yeast as a model . . . to help understand Read More ›

Stuff we mustn’t tell Bill Nye (if anyone still cares where he is or what he is doing) PubMed link for one e coli genome from Liberty University here. Darwin followers free to call police. Follow UD News at Twitter!

Basically, a new polyploid plant species has had more than one separate origin in Scotland. And we still don’t know how that works.* Polyploidy—the heritable condition of possessing more than two complete sets of chromosomes—has always been something of a mystery, and this new find both illuminate it and suggests we should pay more attention to it: Polyploidy is the heritable condition of possessing more than two complete sets of chromosomes. Polyploids are common among plants, as well as among certain groups of fish and amphibians. For instance, some salamanders, frogs, and leeches are polyploids. Many of these polyploid organisms are fit and well-adapted to their environments. … Well, from ScienceDaily: Dr Vallejo-Marin added: “It is impossible to say whether Mimulus Read More ›

This is from a new study published in Nature Communications, and talked about at Phys.Org. Oh, how difficult it is these days to be an “intellectually fulfilled” neo-Darwinian: Humans don’t like being alone, and their genes are no different. Together we are stronger, and the two versions of a gene – one from each parent – need each other. Scientists at the Max Planck Institute for Molecular Genetics in Berlin have analysed the genetic makeup of several hundred people and decoded the genetic information on the two sets of chromosomes separately. In this relatively small group alone they found millions of different gene forms. The results also show that genetic mutations do not occur randomly in the two parental chromosome Read More ›

Here’s a link to a Science Daily article on epigenetics. The authors report that the known and studied method of epigenetic marking, methylation of Histone3=H3, is not only passed down from one cell generation to another during development, but that these epigenetic markings are passed on from one generation of organisms to the next. These findings suggest that the neo-Darwinian mechanisms normally invoked in evolutionary discussions may or may not be critical for “adaptation.” If further studies confirms the widespread phenomena of epigentic markings being handed down from generation to generation, then there may not be much force left to the evolutionary tales we’ve been told over the years. What I mean is this. We are told that organisms, in Read More ›

Are you what you eat? Or what’s eating you?
Novel virus discovered in half the world’s population

A new study led by researchers at San Diego State University has found that more than half the world’s population is host to a newly described virus, named crAssphage, which infects one of the most common types of gut bacteria, Bacteroidetes. This phylum of bacteria is thought to be connected with obesity, diabetes and other gut-related diseases. . . .It’s unknown how the virus is transmitted, but the fact that it was not found in very young infants’ fecal samples suggests that it is not passed along maternally, but acquired during childhood. The makeup of the viral DNA suggests that it’s circular in structure. Further laboratory work has confirmed that the viral DNA is a singular entity, but it’s proven difficult to isolate. . . .
Some of the proteins in crAssphage’s DNA are similar to those found in other well-described viruses. That allowed Edwards’ team to determine that their novel virus is one known as a bacteriophage, which infects and replicates inside bacteria—and using innovative bioinformatic techniques, they predicted that this particular bacteriophage proliferates by infecting a common phylum of gut bacteria known as Bacteriodetes.
Gut punch
Bacteriodetes bacteria live toward the end of the intestinal tract, and they are suspected to play a major role in the link between gut bacteria and obesity. What role crAssphage plays in this process will be a target of future research.. . .

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