Welcome. My name is Frank Slack,
and I'm an associate professor in the Department of Molecular,
Cellular and Developmental Biology at Yale University.
Today I'm going to tell you about something that I've called the silent revolution.
I'll hopefully be able to give you an introduction to
gene regulation on microRNAs and other small RNAs.
So as the name suggests,
microRNAs are small RNAs,
and we now know that they are part of a larger class of RNAs,
which we've just termed non-coding RNAs,
and they've been shown to be very important regulators of gene expression.
In fact, in 2002,
Science Magazine named small RNAs,
like microRNAs, breakthrough of the year and
termed them a new paradigm of gene regulation.
Now, these small RNAs are, in fact,
so small that they escaped our notice for many, many years.
MicroRNAs were only discovered in 1993, for example.
This has led Gary Ruvkun,
one of the founders of the microRNAs,
to actually term them the dark matter of the genome.
But their small size doesn't reflect their importance.
In fact, we now know that they're extremely important regulators on gene expression.
And what I hope to do today is tell you both how
these microRNAs are formed, how they're regulated,
how they actually regulate gene expression
and give you a sense of what their roles are in biology and,
perhaps, also what their roles are in disease and in medicine.
So we now appreciate that gene regulation occurs at multiple levels.
We usually think of gene regulation as occurring
at the level of transcription or translation,
in this case, how DNA is converted into RNA and how RNA is converted into protein.
Of course, we now know that RNA can be reversed transcribed back into DNA.
But it's also true that gene regulation can occur at the level of post-transcriptional,
as well as post-translational levels.
For example, we can regulate how the RNA itself is
used and stabilized and how the protein is used and stabilized.