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Cell-specific occupancy dynamics between the pioneer-like factor Opa/ZIC and Ocelliles/OTX regulate early head development in embryos

Fenelon, Kelli D. and Gao, Fan and Borad, Priyanshi and Abbasi, Shiva and Pachter, Lior and Koromila, Theodora (2022) Cell-specific occupancy dynamics between the pioneer-like factor Opa/ZIC and Ocelliles/OTX regulate early head development in embryos. . (Unpublished)

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During development, embryonic patterning systems direct a set of initially uncommitted pluripotent cells to differentiate into a variety of cell types and tissues. A core network of transcription factors, such as Zelda/POU5F1, Odd-paired (Opa)/ZIC and Ocelliless (Oc)/OTX, are conserved across animals. While Opa is essential for a second wave of zygotic activation after Zelda, it is unclear whether Opa drives head cell specification past gastrulation onset, in theDrosophilaembryo. Our hypothesis is that Opa and Oc are interacting with distinct cis-regulatory regions for shaping cell fates in the embryonic head. Using super-resolution microscopy and epigenomic meta-analysis of single cell RNAseq datasets we find thatopa’s andoc’s overlapping expression domains are dynamic in the head region, with both factors being simultaneously transcribed at the blastula stage. However, analysis of single-embryo RNAseq data reveals a subgroup of Opa-bound genes to be Opa-independent in the cellularized embryo. Interrogation of these genes against Oc ChIPseq combined with in situ data, suggests that Opa is competing with Oc for the regulation of a subgroup of genes later in gastrulation. Specifically, we find that Oc binds to late, head-specific enhancers independently and activates them in a head-specific wave of zygotic transcription, suggesting distinct roles for Oc in the blastula and gastrula stages.

Item Type:Report or Paper (Discussion Paper)
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URLURL TypeDescription Paper
Fenelon, Kelli D.0000-0002-1294-9200
Gao, Fan0000-0001-6832-3402
Borad, Priyanshi0000-0001-8446-5312
Pachter, Lior0000-0002-9164-6231
Koromila, Theodora0000-0001-5504-1369
Additional Information:The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-ND 4.0 International license. We are grateful to Rhea Datta and Angela Stathopoulos for generously providing us with fly lines, antibodies, and ChIPseq data, We would like to further thank Anupama Chandrasekhar for her help with the StarkLab database; Hinduja Sathishkumar and Saubia Zareen, students in the Koromila Lab, for their assistance with administrative tasks and fly husbandry; and Mounia Lagha for helpful discussions. This work was made possible by funding the the UTA STARS program and the Bioinformatics Resource Center at the Beckman Institute of Caltech. The authors have declared no competing interest.
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University of Texas at ArlingtonUNSPECIFIED
Caltech Beckman InstituteUNSPECIFIED
Record Number:CaltechAUTHORS:20230316-182720000.54
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:120165
Deposited By: George Porter
Deposited On:18 Mar 2023 01:52
Last Modified:18 Mar 2023 01:52

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