#bacteriophage

Viruses Can Be Villains or HeroesMost of us are familiar with viruses as the tiny packets of DNA that can infect us and make us sick, and antibiotics can't help. Viruses such as smallpox, hepatitis, rabies, diphtheria, and COVID-19 are often quite deadly. But the world of viruses is much larger than those we've had bad experiences with. Viruses infect animals, plants, funguses, and even bacteria. The viruses, or bacteriophages, that invade bacteria cells keep them at manageable levels, whether in the oceans or in our digestive systems. This is an upside to viruses that equate to "the enemy of my enemy is my friend." Scientists are experimenting with bacteriophages that can attack cancer cells. But viruses have contributed to our ecosystem in other ways. There are two types of virus. Virulent phages are the ones that infect cells, replace their DNA, and use the cell to manufacture more virus. The other type are the temperate phages. These viruses will infect a cell and merge its DNA with that of the cell instead of evicting it. It may lie dormant and then become infectious years down the road. Or it may just create new combinations of DNA. In fact, temperate phages may be the crucial method of inserting genes that change existing life forms. Read how that happens at The Conversation. -via Damn Interesting#virus #phage #bacteriophage #DNA
Viruses Have a Novel Genetic Alphabet in Their DNAAsk any high school biology student how many bases our genetic material DNA has, and you'll get four as the answer: adenine (A), cytosine (C), guanine (G), and thymine (T).But in a series of new studies published in Science, three teams have identified dozens of viruses that has swapped one of the bases in their DNA for a novel one called 2-aminoadenine, later dubbed 'Z'.From Quanta Magazine:The Z base looks like a chemical modification of A; it’s an adenine nucleotide with an extra attachment. But that modest change allows Z to form a triple hydrogen bond with T, which is more stable than the double bond that holds together A-T....since the alterations were “at the deepest level of chemical organization,” [geneticist Philippe Marlière of the University of Evry in France] said, “my instinct told me this is not just an anecdote. This is a profound violation.”#DNA #virus #bacteriophage #biology #syntheticbiology #genetics