A Swedish research group, partly financed by NWO, has discovered a new mechanism for cell division in a microorganism found in extremely hot and acidic conditions. The results of the research offer insights into evolution, but also into the functioning of the human body. The research has been recently published in PNAS, the magazine of the American National Academy of Sciences. Thijs Ettema, member of the research group, received a Rubicon grant from NWO in 2006 to gain experience abroad.
The new mechanism for cell division was discovered in Sulfolobus acidocaldarius, a microorganism found in hot springs in Yellowstone National Park. The organism is a member of the third main group of life on earth, the Archaea. Archaea, like bacteria, are unicellular organisms but in terms of evolution they are more closely related to another main group of living things, the eukaryotes (humans, animals, plants, fungi, etc).
Until now little was known about the proteins that control cell division in the Archaea. With the use of immunofluorescence the researchers determined the location of these proteins in the cell and in doing so discovered that three proteins play a crucial role in the cell division of Sulfolobus acidocaldarius. Once the whole chromosome has been replicated, these three proteins form a band-like structure over the cell equator. One chromosome is then found on each side of this band. The band then squeezes the cell into two so that two new daughter cells are formed. At first it looks like mitosis, as discussed in many a biology lesson. However, mitosis is the process whereby the chromosomes are distributed between the two daughter cells. Cell division is the process whereby the two daughter cells are separated.
It is striking that these cell division proteins are not related to other proteins known to be involved in cell division. Some of the proteins in the new type of cell division are simila
|Contact: Dr T.J.G. Ettema, Uppsala University|
Netherlands Organization for Scientific Research