Please wait while the transcript is being prepared...
0:00
So I'll be talking today about
maintaining the silenced state
of regulatory genes
during development.
0:09
For an organism to develop
properly, the initial fertilized egg
has a bunch of master regulatory
genes that are in a naive state.
In order for the organism to develop
appropriate cell types and cell
lineages, in some
cells, those master
regulatory genes need to be held on.
But in most cells, those
master regulatory genes
need to be held off.
This is a classic problem
in epigenetic regulation.
Exactly the same DNA sequence
is found on the master
regulatory genes, but
in some gene sets,
sequence is kept in an on
state throughout the entirety
of development.
Whereas in other cell
lineages, that set of genes
is kept in an off state.
So to understand how we can
have a fertilized egg create all
of the different body parts
that create a normal organism,
we have to understand how you can
have a regulated state that can be
inherited from one cell
division to the next.
So today I will focus on the
repressive side of that equation.
How do you repress
a gene and then keep
it repressed for all different
levels of cell division?
1:26
This is a problem that's been
appreciated for a long time,
and it's been studied very
thoroughly over the last 80 years.
The studies initiated
by understanding
how Drosophila, the
fruit fly, develops.
In the fruit fly, you need to
go from an embryo to a fly.
And which part of the fly is going
to be which is established early
on in the embryo and
then is remembered
as the embryo becomes
the intact fly.
