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horizontal gene transfer

Horizontal gene transfer in bacteria: Numbers surprise researchers

From ScienceDaily: Gene transfers are particularly common in the antibiotic-resistance genes of Streptococcus pneumoniae bacteria. When mammals breed, the genome of the offspring is a combination of the parents’ genomes. Bacteria, by contrast, reproduce through cell division. In theory, this means that the genomes of the offspring are copies of the parent genome. However, the process is not quite as straightforward as this due to horizontal gene transfer through which bacteria can transfer fragments of their genome to each other. As a result of this phenomenon, the genome of an individual bacterium can be a combination of genes from several different donors. Some of the genome fragments may even originate from completely different species. In a recent study combining machine Read More ›

Origin of life: Horizontal gene transfer “negligible” and endosymbiosis “wrong” as factors in earliest known life?

From science writer Suzan Mazur, author of Paradigm Shifters, continuing her interview at Huffington Post with Swedish deep evolution investigators Charles Kurland and Ajith Harish regarding … their central position on deep evolution, which is that the most recent universal common ancestor (MRUCA) is complex not a simple bacteria and “is the root of eukaryote and akaryote lineages” containing “more than a thousand Superfamilies.” Kurland and Harish think MRUCA represents complex survivors from a now extinct biosphere. On horizontal gene transfer as routine: Charles Kurland: We have to remember there’s only a little background of horizontal gene transfer in bacterial populations. The simple reason is that bacteria eat DNA. So sequences are going in all the time. Most of them get Read More ›

Nature launches new journal: Nature Ecology & Evolution

Here: Multicopy plasmids potentiate the evolution of antibiotic resistance in bacteria As well as allowing horizontal gene transfer, the increased copy number of plasmids could accelerate evolution. Here, it is shown that… More. One can browse four articles for free, include the above. Perhaps they are hoping to accommodate non-Darwinian evolution more formally. Follow UD News at Twitter!

Horizontal gene transfer: Virus carries DNA of black widow spider toxin

Everyone goes a bit nuts at Hallowe’en and I (O’Leary for News) just couldn’t resist this one, before I go back to serious work. From ScienceDaily: Biologists sequencing the genome of the WO virus, which infects the bacterial parasite Wolbachia, have discovered that the phage carries DNA that produces black widow spider toxin: the first time an animal-like DNA has been found in such a virus. Wow, black widow toxin on the move in a virus. Call central casting, we got ourselves a horror flick half written already. “Discovering DNA related to the black widow spider toxin gene came as a total surprise because it is the first time that a phage — a virus that infects bacteria — has Read More ›

Can parasitic plants use hosts’ genes against them?

From ScienceDaily: Sneaky parasitic weeds may be able to steal genes from the plants they are attacking and then use those genes against the host plant, according to a team of scientists. In a study, researchers detected 52 incidents of the nonsexual transfer of DNA — known as horizontal gene transfer, or HGT — from a host plant that later became functional into members of a parasitic plant family known as the broomrapes, said Claude dePamphilis, professor of biology, Penn State. The transferred genes then became functional in the parasitic species. Although considered rare in more plants and other complex species, like plants, HGT may thus occur in some parasitic plants, an insight that could lead to better methods of Read More ›

Horizontal gene transfer: Researchers believe any two major groups of organisms can share genetic codes

This is not the “evolution” your high school textbook set forth. That stuff was Darwinism, plain and simple. From Kelly Robinson and Julie Dunning Hotopp at The Scientist Scientists now recognize that microbes transfer DNA to the plants, fungi, and animals they infect or reside in, and conversely, human long interspersed elements (LINEs) have been found in bacterial genomes. Moreover, researchers have documented LGT [lateral gene transfer, synonymous with HGT – ed.] from fungi to insects and from algae to sea slugs. There is reason to believe that any two major groups of organisms—including humans—can share their genetic codes. People have long been intrigued by the prospect of foreign DNA within our own genomes. Human genomes harbor evidence of beneficial Read More ›

Darwinism is a metaphysic. What is it doing in schoolbook science?

Today? Looking back on the Darwin-in-the-schools wars from the vantage point of rethinking evolution, one calls to mind textbook author Douglas Futuyma’s dictum: Darwin showed that material causes are a sufficient explanation not only for physical phenomena, as Descartes and Newton had shown, but also for biological phenomena with all their seeming evidence of design and purpose. By coupling undirected, purposeless variation to the blind, uncaring process of natural selection, Darwin made theological or spiritual explanations of the life processes superfluous. Together with Marx’s materialistic theory of history and society and Freud’s attribution of human behavior to influences over which we have little control, Darwin’s theory of evolution was a crucial plank in the platform of mechanism and materialism Never Read More ›

Denis Noble: Evolution needs replacement, not extension

In The Paradigm Shifters: Overthrowing “the Hegemony of the Culture of Darwin,” Oxford’s Denis Noble explains to Suzan Mazur why our understanding of evolution needs to be replaced, not merely extended: The reasons I think we’re talking about replacement rather than extension are several. The first is that the exclusion of any form of acquired characteristics being inherited was a central feature of the modern synthesis. IN other words, to exclude any form of inheritance that was non-Mendelian, that was Lamarckian-like, was an essential part of the modern synthesis. What we are now discovering is that there are mechanisms by which some acquired characteristics can be inherited, and inherited robustly. So it;s a bit odd to describe adding something like that Read More ›

HGT: Gut microbes jump to insect hosts

From ScienceDaily: Many plant-feeding insects need microbial enzymes, such as pectinases, that degrade plant cell walls; yet some insects have overcome this dependency in a surprising way. Now researchers found that stick insects make microbial enzymes themselves. From an ancestral gut microbe, the genes for the essential enzymes simply ‘jumped’ as they are to their insect host. “Jumped”? “As they are?” Who predicted that? Beyond enzymes, horizontal gene transfer can provide any number of new abilities, and our microbiome provides an immense source of potential species-altering proteins. “The idea that genes from microbes living in our guts can suddenly become part of our genomes and change the course of our evolutionary history, that’s an incredible finding,” Shelomi concludes. Paper. (public Read More ›

Horizontal gene transfer: Mapping antibiotic resistance

From ScienceDaily: Bacteria possess the ability to take up DNA from their environment, a skill that enables them to acquire new genes for antibiotic resistance or to escape the immune response. Scientists have now mapped the core set of genes that are consistently controlled during DNA uptake in strep bacteria, and they hope the finding will allow them to cut off the microbes’ ability to survive what doctors and nature can throw at them. It’ll be interesting to see who wins this one, man or bug. HGT gives bacteria a vast library of existing solutions. Earlier studies of competence had pointed to more than 300 active genes. The new study identifies only 83 genes in 29 regions of the strep Read More ›

Water bear’s hybrid genome now disputed

From Washington Post: Tardigrades — otherwise known as water bears or (gasp) moss piglets — are weird. They can survive in the vacuum of space, for starters. So when researchers at the University of North Carolina announced on Nov. 23 that the minuscule animal had hitherto unheard of ratios of DNA borrowed from plants, fungi and bacteria, many in the scientific community were more than happy to believe the strange findings. Now, a lab at the University of Edinburgh claims the results must be an error. … “We just hadn’t seen evidence of that at all,” Blaxter said. The fact that tardigrades have genes they’ve acquired through horizontal gene transfer isn’t up for dispute. But the record-breaking volume didn’t line Read More ›

This just in: One sixth of water bear’s genes are from microbes

From The Atlantic: The toughest animals in the world aren’t bulky elephants, or cold-tolerant penguins, or even the famously durable cockroach. Instead, the champions of durability are endearing microscopic creatures called tardigrades, or water bears. They live everywhere, from the tallest mountains to the deepest oceans, and from hot springs to Antarctic ice. They can even tolerate New York. They cope with these inhospitable environments by transforming into a nigh-indestructible state. Their adorable shuffling gaits cease. Their eight legs curl inwards. Their rotund bodies shrivel up, expelling almost all of their water and becoming a dried barrel called a “tun.” Their metabolism dwindles to near-nothingness—they are practically dead. And in skirting the edge of death, they become incredibly hard to Read More ›

How horizontal gene transfer has shaped the web of life

“using examples of HGT among prokaryotes, between prokaryotes and eukaryotes, and even between multicellular eukaryotes” From Nature Reviews Genetics:, should feature many useful examples: Here’s the abstract: Horizontal gene transfer (HGT) is the sharing of genetic material between organisms that are not in a parent–offspring relationship. HGT is a widely recognized mechanism for adaptation in bacteria and archaea. Microbial antibiotic resistance and pathogenicity are often associated with HGT, but the scope of HGT extends far beyond disease-causing organisms. In this Review, we describe how HGT has shaped the web of life using examples of HGT among prokaryotes, between prokaryotes and eukaryotes, and even between multicellular eukaryotes. We discuss replacement and additive HGT, the proposed mechanisms of HGT, selective forces that Read More ›

Crunchy granola alert: Butterflies may be GMOs

Ah yes ,the time of year in many parts of North America when, everywhere you look, there is a Monarch (an orange butterfly) flap gliding around. They migrate in vast masses from mid-north Canada to Mexico. Now, from New Scientist: Wasps first turned bracoviruses into biological weapons around 100 million years ago. There are now thousands of species of braconid wasp, each of which parasitises a specific butterfly or moth and produces a unique bracovirus carrying a set of genes that is different to those of other wasp species. But sometimes things go awry. Wasps occasionally lay an egg in the wrong host, for instance, in which case the wasp larva may not survive. In such cases, if genes from Read More ›

HGT: Growth of antibiotic resistance termed “bacterial sex”

From ScienceDaily: Biologist investigates how gene-swapping bacteria evade antibiotics “One of the prevailing theories for why bacteria make these antibiotic compounds is to fight off competition. But the bacteria that make the antibiotics have to be resistant to those antibiotics. Therefore, many encode antibiotic resistance genes against their own products.” Random genetic mutation is one way bacteria become antibiotic resistant, but another way is by exchanging antibiotic resistance genes with one another in close quarters, such as in human wounds or on hospital surfaces. In a recent study, published in June in the Journal of Bacteriology, Palmer and her colleagues shed light on a gene-swapping process called conjugation, which, she tells her students, is like bacterial sex. “These bacteria utilize Read More ›