arie Delattre was studying the sexual reproduction practices of microscopic worms when she noticed something unexpected. Under the microscope, an embryo of the nematode Mesorhabditis belari was dividing as it should, progressing from one cell to two to four. But inside a few cells she saw an inexplicable spray of DNA fragments floating around where they didn’t belong. “There was DNA everywhere, inside the nuclei and outside the nuclei — big chunks of DNA,” she said. “I thought it was a dead embryo.” The embryo was not dead, but it was doing something that usually only dead cells do: destroying its genome.
What Delattre had stumbled across
What Delattre had stumbled across, and what she and her lab Phone Number List described in a paper published in August in Current Biology.Was an instance of programmed DNA elimination (PDE). In which organisms seem to purposefully eliminate portions of their genome. It’s an odd phenomenon that flies in the face of the precept that a genome is a vital. Sacrosanct resource to be passed on faithfully to the next generation. So far, researchers have identified PDE in only about 100. Species across all branches of life.
Delattre’s new paper
In addition to confirming the existence CZ Leads of another case of PDE, Delattre’s new paper also hints at an explanation for it. PDE points to a long-running fight between cells and DNA sequences that are of no use to their owner, or maybe even weigh it down. Like gardeners, cells must protect their genomes to remain functional and productive. What should a cell do when the weeds come in? The new study suggests that some species, like M. belari, might just pull the weeds out using PDE. Despite its seeming novelty, PDE was discovered in the early days of molecular biology
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