• Question: Will we ever lose our nucleus so, like bacteria, our cells can swap DNA in our body (and potentially with other people) to become more resistant to disease?

    Asked by tobyxmas18 to Reka, Judith, Aoife, Anthony, Alice on 4 Jan 2019.
    • Photo: Reka Nagy

      Reka Nagy answered on 4 Jan 2019:

      This is unlikely to happen within our lifetimes, or even over the course of millions of years. Bacteria are single-celled organisms (so everything they do is done by that one cell) while we and many of the animals on Earth are multicellular – they have many varied, specialised cells, each of which is best suited to carrying out specific tasks.

      Within these cells, there are different compartments, including the nucleus, that help organise things. The nucleus is one of these, and it contains our DNA within it, protecting it and coordinating the processes needed to make copies of it and turn it into RNA and protein. If a cell suddenly had no nucleus, it couldn’t carry out these processes, and would therefore die – and by not leaving behind any copies of itself, it could not lead to a scenario where nucleus-less human beings become the norm!

    • Photo: Judith Sleeman

      Judith Sleeman answered on 4 Jan 2019:

      It’s thought that eukaryotic cells (ones with a nucleus, like ours) evolved from a relationship between bacteria and archea (two different types of single-celled organisms without nuclei), so to lose the nucleus would be sort of backwards evolution. The ways the nucleus and cytoplasm in our cells interact are very highly controlled, so I can’t see it happening. Plant and mammalian genomes do contain sections of DNA originally from viruses, though, so DNA transfer can occur even with the nucleus present.

    • Photo: Anthony Redmond

      Anthony Redmond answered on 7 Jan 2019:

      The other answers here explain why this is unlikely to happen this really well! But here’s some other stuff to think about:

      We may not be able to transfer DNA as individuals, but we do have a trick up our multicellular sleeves as a species that poor single-celled bacteria do not: Sexual reproduction! While the DNA transferred between bacterial species may have a greater impact on the biology of bacterial species (new genes acquired from distantly related species might allow them to survive in new environments or resist antibiotics [hopefully not!]), sexual reproduction is absolutely vital to the evolution and maintenance of disease resistance in our species (and most other eukaryotes).

      Also, some really important cells in your body don’t have a nucleus! But they also don’t have any DNA (and sadly can’t receive any from other organisms)! These are mature red blood cells that transport oxygen around our bodies. We think that this occurs to allow packing of more oxygenated haemoglobin molecules into each cell, to allow the cells to squeeze into tiny capillaries and better access hard to reach body parts, and to avoid the red blood cell itself using up all of the oxygen that is meant to be delivered to other cells!