I have
NIGMS R35, impact score 12
NIHGRI R21, 4th percentile
NHGRI R01, 7th percentile (co-I)
and it seems like none will be funded. 0/3.

PO (who has been very helpful) said "Unfortunately, I do not expect this application will be selected for funding in FY25."

😭

Thanks to Ellie, Natalie, and @corinnecroslyn.bsky.social for driving these projects and to everyone who helped along the way.

Check out the full preprint here:
doi.org/10.1101/2025...

10/10 (end)

It also means that there is a brief but perhaps significant time in development when the maternal and paternal genomes are very asymmetric in their methylation state.

Ellie's model predicts that the paternal genome "catches up" about an hour after ZGA.

This may have biological implications.
9/10

So what does this mean?

We think it’s a beautiful example of how histone modifications can be inherited in cis through read-write feedback, and indicates that the K27me2 state has sufficient information to do this.
8/10

To test that (because flies are the best) Ellie used mutants that produce haploid embryos (just maternal chromatin). If the model was right, all chromatin should now retain K27me2.

And that’s exactly what she found.
7/10

Sure enough, K27me2 survives! But there's a twist: only half the chromatin stains positive.

Her model suggested a reason: the surviving methylation might be from mom's genome, not dad's.
6/10

Her model predicted what we already knew: fast divisions erase H3K27me3. But it also made a new prediction: lower-order methylation states like H3K27me2 might persist through the rapid divisions.

So she tested it.
5/10

Ellie, a PhD student in the lab, built a model of this process. She started from a published computational framework, added our new measurements, and asked: what happens to histone methylation during these fast cycles?
4/10

In the first study, we found that these rapid early divisions not only erase H3K27me3 but also that key nucleators of this modification are kept out of the nucleus until just before the zygotic genome activates.
3/10