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Hi. I'm Dr. Stacy Blain
from SUNY Downstate
Health Science Center.
The topic of today's talk is
the mammalian cell cycle.
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While we have many different
cells in our body,
we have liver cells
that do liver things,
and breast cells that
do breast things,
the one commonality
between all of these cells
is their ability to regulate
their proliferation.
These cells have to
decide when they make
a duplicate copy of
themselves or alternatively,
whether they remain in a
quiet or quiescent state.
Some cells in our body are
dividing all the time.
These would be our skin cells
and members of our GI tract.
These cells are very
short-lived and there needs
to be a constant
birthing of new cells.
Some cells will only
divide when they
receive the appropriate
signals from
their extracellular
environment, such as
our liver cells, or members of
our hematopoietic lineages.
When our livers gets damaged,
those cells can exit
that quiet state,
make a duplicate copy,
restore the liver to
the appropriate size,
and then re-enter
that quiescent state.
Some of our cells have
the ability to divide
but do not divide.
These might be members of
our cardiac lineages or
a neuronal lineages,
and they live in that long-term
quiescent state for decades.
This process of deciding when to
divide or not is all
important and it
help to ensure the integrity of
the organs, as well as the
size and the functionality.
This decision to divide,
which is constant,
happens every second,
every day in all of
our cells, is regulated
by this balance
between proliferative go signals
and anti-proliferative
stop signals.
