Phillipe Silar and Fabienne Malagnac of University of Paris 7
will present a talk on cytoplasmic epigenetic,
and will mostly focus on inheritance by cytoplasmic continuity.
It was demonstrated about 50 years ago,
that DNA is the major carrier of information
that pass from mother to daughter cells.
This DNA-based information accounts for the classical Mendelian inheritance,
but also for the cytoplasmic inheritance brought about by DNA
contained within mitochondria and plasmids,
but also by viruses and other infectious factors present within the cytoplasms.
However, at about the same time,
several examples of non-DNA based inheritance were postulated and later on discovered.
Two broad classes of such phenomena were made:
structural inheritance, whereby your preexisting structure
is necessary for the correct folding of a newly formed one
and regulatory inheritance in which the state of a metabolic or regulatory network,
directs the status of the same network in the daughter cells.
The hallmarks of this inheritance
are that the characters are frequently unstable,
and may switch spontaneously and with high frequency
between several so-called states,
and that this inheritance is achieved by cellular continuity.
This means that when extracted from the cell,
this information loses its coding capacity.
As we shall see,
these are general properties of this phenomena,
but may not be fulfilled in all cases.