It appears to me that AbdA and AbdB are more commonly ectopically expressed in replicating tissues of Scm mutants by shRNA knockdown. For example the over-replicating posterior and anterior regions found in some embryos also express these genes. (should have taken higher res DAPI to ID replicating nuclei).
Also seems preferentially to find pairs of cells (recently replicated sisters?) rather than a stochastic distribution of single cells. And some association with possible mitotic cells.
Finally, the endo-replicating ectodermal / extra-embryonic cells have seem to preferentially express AbdB/A (should confirm that they do not in wildtype).
Should also repeat with AbdB protein not in 488 channel, which has extra background in these tissues already.
Probably worth going back to confocal and taking more images of these guys too to see how well these trends hold up.
Literature on this idea:
Lanzuolo 2011 (supplement) Main point is dilution model of PcG propagation through replication. Claim is that PcG proteins specifically recruited to BX-C PRE in early S phase (prior to replication of the locus / of PREs).
Pena-Diaz 2013 — via transcription profiling during cell cycle, show that some PcG genes get upregulated during DNA replication (consistent with preferential loss of silencing in mutants).