“Selfish” Gene Enhances Own Transmission at Expense of Organism’s Fertility

These glowing images of yeast (Schizosaccharomyces kambucha) reproductive cells show an example of a selfish gene at work. Here, the selfish gene boosts its chances of being passed to the next generation by producing both a toxin (stained cyan) and an antitoxin (stained magenta). Cells with a copy of the selfish gene are protected by the antitoxin, left and bottom ovals. Those without the selfish gene are destroyed by the toxin. Scientists suspect that selfish genes could be operating throughout many organisms’ genomes, possibly having a major impact on how genetic material is inherited over generations. Credit: Image courtesy of María Angélica Bravo Núñez and Nicole Nuckolls. There’s an old saying that rules are meant to be broken. In the 1860s, Gregor Mendel found that each copy of a gene in an organism has an equal chance of being passed to the next generation. According to this simple rule, each version of a gene gets passed to offspring with the same frequency. The natural selection process can then operate efficiently, favoring the genes that produce an advantage for an organism’s survival or reproductive success and, over successive generations, eliminating genes from the gene pool that bring a disadvantage. Of course, the way organisms inherit genes is not as straightforward as Mendel’s work predicted. In natural systems, inheritance often fails to follow the rules. One culprit scientists are identifying again and again are what are called “selfish gene...
Source: Biomedical Beat Blog - National Institute of General Medical Sciences - Category: Research Authors: Tags: Genetics DNA Evolutionary Biology Genes Source Type: blogs