Extreme Healing, Weird Genomics, and Bloodsucking Invaders

Quick quiz:  Which organism . . . Can regrow a severed spinal cord? Is a culinary delicacy overseas but an invasive pest in the U.S.? Reveals insights about tissue regeneration, evolution, and cancer biology? Give up? It’s the sea lamprey. A direct descendant of one of the first organisms to develop a backbone, these remarkable creatures are considered “living fossils.” Best of all, they can regrow a severed spinal cord—a feat we humans can only dream about. Credit: Jeramiah Smith, University of Kentucky. This leechlike creature has several unusual—and enviable—characteristics that make it an ideal research organism for a variety of scientific investigations. Lampreys can do something no human has ever accomplished: repair a damaged spinal cord. Humans with spinal cord injuries are often paralyzed and lose bowel and bladder control. Lampreys, in contrast, can recover fully, even after their spinal cords are sliced clean through. Within 12 weeks, they’re swimming and functioning normally. Genetically speaking, lampreys are also highly unusual. Most animals guard their genomes zealously, since altering a single letter of DNA code could cause a devastating genetic disease or set the stage for cancer. Lampreys, meanwhile, toss out 20 percent of their DNA while still embryos. The process is called programmed genome rearrangement (PGR). Some researchers suspect that it might help protect lampreys from cancer. How can throwing away hundreds—or even thousan...
Source: Biomedical Beat Blog - National Institute of General Medical Sciences - Category: Research Authors: Tags: Genetics Cellular Processes Chromosomes Cool Creatures Research Organisms Wound Healing Source Type: blogs