0:00
My name is Dale Dorsett from
the Department of Biochemistry
and Molecular Biology at the
Saint Louis University School
of Medicine, and I'm going
to talk about gene regulation
by cohesin in Drosophila,
which has provided
insights into certain
human conditions.
0:18
In my talk, I'm going to
cover four major points.
The first is, is that sister
chromatids cohesion proteins
regulate many genes that
are important for growth
and development?
The second point is going to be
about a specific mechanism by which
cohesin controls gene expression,
and that said, cohesin collaborates
with Polycomb silencing
proteins to restrain,
but not actually silence genes.
We're also going to talk about
how cohesin binds genes that have
paused RNA polymerase, and how it
controls the ability of that paused
polymerase to become
elongating polymerase.
And finally, I'm going to summarize
how gene regulation by cohesin
can explain diverse
developmental deficits that occur
in a human genetic syndrome,
Cornelia de Lange syndrome.
1:08
For my laboratory, the
entry point into this work
was an attempt to explain the
wing-nicking phenotype displayed
by the original Notch receptor
mutation discovered many years ago
by Thomas Hunt Morgan and
Calvin Bridges, in Drosophila.
1:26
Work by many laboratories
over several years
had led to the realization that the wing-nicking phenotype in Notch mutants
probably derives from underexpression of the cut gene
during the third instar
larval development,
along the presumptive
future wing margin.
So activation of the Notch receptor
in dorsal and ventral cells
activates cut in a thin
stripe of cells that
will eventually form
the adult wing margin.
