Life, but Not as We Know It: Rudimentary Form of Life Sidesteps Normal Replication Process

A rudimentary form of life that is found in some of the harshest environments on earth is able to sidestep normal replication processes and reproduce by the back door, researchers at The University of Nottingham have found.

The study, published in the journal Nature, centres on Haloferax volcanii — part of a family of single-celled organisms called archaea that until recently were thought to be a type of bacteria.

The findings, led by scientists from the University’s School of Life Sciences, could offer new insights into how defective cells can multiply out of control in diseases such as cancer. „We have shown that in some organisms, the replication origins — genetic switches that control DNA replication — are not only unnecessary but cells will actually grow faster when these origins are not present. This is totally unexpected and has forced us to re-evaluate one of the cornerstones of DNA biology.”

In order to reproduce, all life forms need to copy their DNA before the cell can divide. They do this via a series of ‘replication origins’ that are located around their chromosomes and to which proteins bind in order to start the replication process.

In eukaryotes such as humans if these replication origins are eliminated it prevents replication and eventually leads to cell death. However, the Nottingham study, funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the Royal Society, found that the Haloferax volcanii is able to spontaneously begin a chain reaction of replication all around its chromosomes even when its replication origins have been eliminated.