A surprise discovery has shown how some cells may be capable of exercising control over their own destiny.
Immunology researchers from Walter and Eliza Hall Institute drew this conclusion after studying B cells, immune system cells that can make antibodies.
An antibody, also known as an immunoglobulin, is a large Y-shaped protein which identifies and neutralizes invasive bacteria and viruses, the journal Science reports.
B cells can have multiple fates. Some of the more common fates are to die, divide, become an antibody-secreting cell or change what antibody they make. This all happens while the cells are proliferating in the lymph nodes, according to an Eliza Hall statement.
The commonly-held view is that a cell's fate is determined by external cues such as the presence of particular hormones or cell signalling molecules.
However, Eliza head of immunology, Phil Hodgkin and colleagues Mark Dowling, Cameron Wellard and Jie Zhou predicted that cell fates are, to a large extent, determined by internal processes.
They tested their theory by recreating the conditions required for B cells to develop into different cell types and then filmed the cells, working with John Markham from the National Information and Communications Technology, to develop new technology and image analysis methods.
Hodgkin said the cells behaved as though there were internal machines that governed the cells' fates.
"Each of these internal machines is like a little clock or timer for division, death, what type of antibody they make and whether they become antibody secreting cells," he said.
Dowling said "Each cell will, in some sense, set up a clock that starts ticking for each of the outcomes and whatever clock goes off first is the decision that the cell makes."
"The cell is trying to do everything but only one fate wins," he said.