{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T16:26:18Z","timestamp":1786983978692,"version":"build-2736575974"},"posted":{"date-parts":[[2026,8,13]]},"group-title":"Cell Biology","reference-count":49,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T00:00:00Z","timestamp":1786579200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"award":["T32 HG000047"],"award-info":[{"award-number":["T32 HG000047"]}],"id":[{"id":"https:\/\/ror.org\/01cwqze88","id-type":"ROR","asserted-by":"publisher"}]},{"award":["T32 GM132022"],"award-info":[{"award-number":["T32 GM132022"]}],"id":[{"id":"https:\/\/ror.org\/01cwqze88","id-type":"ROR","asserted-by":"publisher"}]},{"award":["R01 GM117420"],"award-info":[{"award-number":["R01 GM117420"]}],"id":[{"id":"https:\/\/ror.org\/01cwqze88","id-type":"ROR","asserted-by":"publisher"}]},{"award":["R35 GM139653"],"award-info":[{"award-number":["R35 GM139653"]}],"id":[{"id":"https:\/\/ror.org\/01cwqze88","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,8,13]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>\n                  Heterochromatin replication isn\u2019t random or uniform, but occurs in a characteristic spatial and temporal pattern. Previous studies produced conflicting models for pericentric heterochromatin (PCH) replication, suggesting either that heterochromatic sequences translocate to the domain surface for replication, or that replication can also occur internally through localized decondensation. To distinguish true overlap from peripheral enrichment around an irregular PCH domain, we developed FOC-Map, a colocalization analysis approach that combines segmentation of one channel with binning of the other. Applying FOC-Map to three-dimensional Airyscan imaging of cultured\n                  <jats:italic>Drosophila<\/jats:italic>\n                  cells, we find that replication foci at the onset of late S-phase are confined to the outer boundary of the PCH domain, forming a shell-like pattern with little overlap into the HP1a-rich interior. As late S-phase progresses, replication foci are observed within the domain, localizing to low-HP1a regions interspersed between more condensed regions. We then assessed the distribution of CDC45, a rate-limiting replication initiation factor, and found that CDC45 foci are depleted from the PCH domain throughout the cell cycle. We propose that low levels of CDC45 within HP1a-rich PCH limit replication initiation to the domain periphery, giving rise to the shell-like pattern of replication foci that progressively works inward until PCH replication is complete.\n                <\/jats:p>","DOI":"10.64898\/2026.08.13.744572","type":"posted-content","created":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T01:50:18Z","timestamp":1786672218000},"source":"Crossref","is-referenced-by-count":0,"title":["Outside-in progression of heterochromatin replication and exclusion of CDC45 from the PCH domain in\n                  <i>Drosophila<\/i>"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-8587-0448","authenticated-orcid":false,"given":"Collin","family":"Hickmann","sequence":"first","affiliation":[{"name":"Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6727-5883","authenticated-orcid":false,"given":"Srigokul","family":"Upadhyayula","sequence":"additional","affiliation":[{"name":"Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA"},{"name":"Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA"},{"name":"Chan Zuckerberg Biohub, San Francisco, CA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1534-0385","authenticated-orcid":false,"given":"Gary H.","family":"Karpen","sequence":"additional","affiliation":[{"name":"Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026081708251477000_2026.08.13.744572v1.1","doi-asserted-by":"publisher","DOI":"10.1038\/nrm.2017.119"},{"key":"2026081708251477000_2026.08.13.744572v1.2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev-cellbio-100617-062653"},{"key":"2026081708251477000_2026.08.13.744572v1.3","doi-asserted-by":"publisher","DOI":"10.1038\/nature22822"},{"key":"2026081708251477000_2026.08.13.744572v1.4","doi-asserted-by":"publisher","DOI":"10.1038\/nature22989"},{"key":"2026081708251477000_2026.08.13.744572v1.5","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pbio.2005687"},{"key":"2026081708251477000_2026.08.13.744572v1.6","doi-asserted-by":"publisher","DOI":"10.1101\/gad.272237.115"},{"key":"2026081708251477000_2026.08.13.744572v1.7","doi-asserted-by":"publisher","DOI":"10.1038\/sj.emboj.7600362"},{"key":"2026081708251477000_2026.08.13.744572v1.8","doi-asserted-by":"publisher","DOI":"10.1002\/bies.201100176"},{"key":"2026081708251477000_2026.08.13.744572v1.9","doi-asserted-by":"publisher","DOI":"10.1080\/19491034.2019.1688932"},{"key":"2026081708251477000_2026.08.13.744572v1.10","doi-asserted-by":"publisher","DOI":"10.1016\/j.cub.2010.10.021"},{"key":"2026081708251477000_2026.08.13.744572v1.11","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2200780119"},{"key":"2026081708251477000_2026.08.13.744572v1.12","doi-asserted-by":"crossref","unstructured":"Colmenares, S. U. et al. Expanding the HP1a-binding consensus and molecular grammar for heterochromatin assembly. Nucleic Acids Research 53, gkaf976 (2025).","DOI":"10.1093\/nar\/gkaf976"},{"key":"2026081708251477000_2026.08.13.744572v1.13","doi-asserted-by":"publisher","DOI":"10.1146\/annurev-biochem-072321-110228"},{"key":"2026081708251477000_2026.08.13.744572v1.14","doi-asserted-by":"publisher","DOI":"10.1016\/j.molcel.2009.12.030"},{"key":"2026081708251477000_2026.08.13.744572v1.15","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M204438200"},{"key":"2026081708251477000_2026.08.13.744572v1.16","doi-asserted-by":"publisher","DOI":"10.1080\/15384101.2016.1152424"},{"key":"2026081708251477000_2026.08.13.744572v1.17","doi-asserted-by":"publisher","DOI":"10.1016\/j.cub.2011.11.038"},{"key":"2026081708251477000_2026.08.13.744572v1.18","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0017533"},{"key":"2026081708251477000_2026.08.13.744572v1.19","doi-asserted-by":"publisher","DOI":"10.1152\/ajpcell.00462.2010"},{"key":"2026081708251477000_2026.08.13.744572v1.20","doi-asserted-by":"publisher","DOI":"10.1242\/jcs.103.3.857"},{"key":"2026081708251477000_2026.08.13.744572v1.21","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2818.1993.tb03313.x"},{"key":"2026081708251477000_2026.08.13.744572v1.22","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2818.2006.01706.x"},{"key":"2026081708251477000_2026.08.13.744572v1.23","doi-asserted-by":"publisher","DOI":"10.1083\/jcb.105.4.1549"},{"key":"2026081708251477000_2026.08.13.744572v1.24","doi-asserted-by":"publisher","DOI":"10.1016\/0014-4827(86)90583-5"},{"key":"2026081708251477000_2026.08.13.744572v1.25","doi-asserted-by":"publisher","DOI":"10.1016\/S0092-8674(01)80009-X"},{"key":"2026081708251477000_2026.08.13.744572v1.26","doi-asserted-by":"publisher","DOI":"10.1101\/2024.03.22.586000"},{"key":"2026081708251477000_2026.08.13.744572v1.27","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0803978105"},{"key":"2026081708251477000_2026.08.13.744572v1.28","doi-asserted-by":"publisher","DOI":"10.15252\/embj.201488307"},{"key":"2026081708251477000_2026.08.13.744572v1.29","doi-asserted-by":"publisher","DOI":"10.1083\/jcb.202009147"},{"key":"2026081708251477000_2026.08.13.744572v1.30","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0005899"},{"key":"2026081708251477000_2026.08.13.744572v1.31","doi-asserted-by":"publisher","DOI":"10.1007\/s10577-009-9093-3"},{"key":"2026081708251477000_2026.08.13.744572v1.32","doi-asserted-by":"crossref","unstructured":"Ciardo, D. , Goldar, A. & Marheineke, K . On the Interplay of the DNA Replication Program and the Intra-S Phase Checkpoint Pathway. Genes 10, 94 (2019).","DOI":"10.3390\/genes10020094"},{"key":"2026081708251477000_2026.08.13.744572v1.33","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-023-39332-5"},{"key":"2026081708251477000_2026.08.13.744572v1.34","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1903418116"},{"key":"2026081708251477000_2026.08.13.744572v1.35","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0809350106"},{"key":"2026081708251477000_2026.08.13.744572v1.36","doi-asserted-by":"publisher","DOI":"10.1021\/acs.biochem.8b00401"},{"key":"2026081708251477000_2026.08.13.744572v1.37","doi-asserted-by":"publisher","DOI":"10.1016\/0014-5793(95)00159-7"},{"key":"2026081708251477000_2026.08.13.744572v1.38","doi-asserted-by":"publisher","DOI":"10.1101\/gr.097873.109"},{"key":"2026081708251477000_2026.08.13.744572v1.39","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/gkac003"},{"key":"2026081708251477000_2026.08.13.744572v1.40","doi-asserted-by":"crossref","unstructured":"Miotto, B. , Ji, Z. & Struhl, K . Selectivity of ORC binding sites and the relation to replication timing, fragile sites, and deletions in cancers. Proc. Natl. Acad. Sci. U.S.A. 113, (2016).","DOI":"10.1073\/pnas.1609060113"},{"key":"2026081708251477000_2026.08.13.744572v1.41","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2443.2007.01090.x"},{"key":"2026081708251477000_2026.08.13.744572v1.42","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/28.20.3897"},{"key":"2026081708251477000_2026.08.13.744572v1.43","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-022-33887-5"},{"key":"2026081708251477000_2026.08.13.744572v1.44","doi-asserted-by":"publisher","DOI":"10.13025\/16945"},{"key":"2026081708251477000_2026.08.13.744572v1.45","doi-asserted-by":"publisher","DOI":"10.1083\/jcb.146.4.709"},{"key":"2026081708251477000_2026.08.13.744572v1.46","doi-asserted-by":"publisher","DOI":"10.17863\/CAM.16510"},{"key":"2026081708251477000_2026.08.13.744572v1.47","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0602400103"},{"key":"2026081708251477000_2026.08.13.744572v1.48","doi-asserted-by":"publisher","DOI":"10.1016\/j.cell.2024.05.024"},{"key":"2026081708251477000_2026.08.13.744572v1.49","doi-asserted-by":"publisher","DOI":"10.1101\/gr.101790.109"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.08.13.744572","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T15:25:25Z","timestamp":1786980325000},"score":1,"resource":{"primary":{"URL":"http:\/\/biorxiv.org\/lookup\/doi\/10.64898\/2026.08.13.744572"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,13]]},"references-count":49,"URL":"https:\/\/doi.org\/10.64898\/2026.08.13.744572","relation":{},"subject":[],"published":{"date-parts":[[2026,8,13]]},"subtype":"preprint"}}