{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T15:37:21Z","timestamp":1785425841350,"version":"3.56.0"},"posted":{"date-parts":[[2026,4,2]]},"group-title":"Molecular Biology","reference-count":13,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,4,2]],"date-time":"2026-04-02T00:00:00Z","timestamp":1775088000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"id":[{"id":"https:\/\/ror.org\/006w34k90","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,4,2]]},"abstract":"<jats:title>Summary<\/jats:title>\n                <jats:p>\n                  The coleoid cephalopods (octopus, cuttlefish, and squid) are emerging model organisms for neuroscience, development, and evolutionary biology. Determining their sex early in life is critical for population management and controlled experiments. Here, we present a protocol to non-invasively determine the sex of multiple cephalopod species as young as 3 hours post-hatching using a skin swab and quantitative PCR (qPCR). We describe steps for designing qPCR primers, swabbing live animals, extracting DNA, running the qPCR, and analyzing the results. For complete details on the use and execution of this protocol, please refer to Rubino et al.\n                  <jats:sup>1<\/jats:sup>\n                <\/jats:p>\n                <jats:sec>\n                  <jats:title>Highlights<\/jats:title>\n                  <jats:list list-type=\"bullet\">\n                    <jats:list-item>\n                      <jats:p>Swab live cephalopods as early as 3 hours post-hatching<\/jats:p>\n                    <\/jats:list-item>\n                    <jats:list-item>\n                      <jats:p>Extract DNA from cephalopod skin swabs<\/jats:p>\n                    <\/jats:list-item>\n                    <jats:list-item>\n                      <jats:p>Perform qPCR-based sex determination<\/jats:p>\n                    <\/jats:list-item>\n                    <jats:list-item>\n                      <jats:p>Design and validate qPCR primers for new species<\/jats:p>\n                    <\/jats:list-item>\n                  <\/jats:list>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Graphical abstract<\/jats:title>\n                  <jats:fig id=\"ufig1\" position=\"float\" fig-type=\"figure\" orientation=\"portrait\">\n                    <jats:graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"715692v1_ufig1\" position=\"float\" orientation=\"portrait\"\/>\n                  <\/jats:fig>\n                <\/jats:sec>","DOI":"10.64898\/2026.03.31.715692","type":"posted-content","created":{"date-parts":[[2026,4,2]],"date-time":"2026-04-02T16:30:11Z","timestamp":1775147411000},"source":"Crossref","is-referenced-by-count":0,"title":["Protocol for genotyping cephalopod sex using a skin swab and quantitative PCR"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7149-6088","authenticated-orcid":false,"given":"Frederick A.","family":"Rubino","sequence":"first","affiliation":[{"name":"Department of Biology, Whitehead Institute, Massachusetts Institute of Technology, Cambridge, MA, USA"},{"name":"The Mortimer B. Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Connor J.","family":"Gibbons","sequence":"additional","affiliation":[{"name":"The Mortimer B. Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas J.","family":"Mungioli","sequence":"additional","affiliation":[{"name":"The Mortimer B. Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Scott T.","family":"Small","sequence":"additional","affiliation":[{"name":"Institute of Ecology and Evolution, University of Oregon, Eugene, OR, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabrielle C.","family":"Coffing","sequence":"additional","affiliation":[{"name":"Institute of Ecology and Evolution, University of Oregon, Eugene, OR, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4381-4680","authenticated-orcid":false,"given":"Andrew D.","family":"Kern","sequence":"additional","affiliation":[{"name":"Institute of Ecology and Evolution, University of Oregon, Eugene, OR, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5918-6327","authenticated-orcid":false,"given":"Tessa G.","family":"Montague","sequence":"additional","affiliation":[{"name":"The Mortimer B. Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, NY, USA"},{"name":"Howard Hughes Medical Institute, Columbia University, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026040605001286000_2026.03.31.715692v1.1","doi-asserted-by":"publisher","DOI":"10.1101\/2025.10.28.685099.abstract"},{"key":"2026040605001286000_2026.03.31.715692v1.2","doi-asserted-by":"publisher","DOI":"10.1016\/j.conb.2024.102876"},{"key":"2026040605001286000_2026.03.31.715692v1.3","doi-asserted-by":"publisher","DOI":"10.1016\/j.cub.2023.08.095"},{"key":"2026040605001286000_2026.03.31.715692v1.4","doi-asserted-by":"publisher","DOI":"10.1016\/j.cub.2013.10.021"},{"key":"2026040605001286000_2026.03.31.715692v1.5","doi-asserted-by":"publisher","DOI":"10.1371\/JOURNAL.PONE.0152048"},{"key":"2026040605001286000_2026.03.31.715692v1.6","doi-asserted-by":"publisher","DOI":"10.1016\/j.cub.2015.09.066"},{"key":"2026040605001286000_2026.03.31.715692v1.7","doi-asserted-by":"publisher","DOI":"10.1093\/icb\/icv049"},{"key":"2026040605001286000_2026.03.31.715692v1.8","doi-asserted-by":"publisher","DOI":"10.1146\/annurev-animal-060322-114534"},{"key":"2026040605001286000_2026.03.31.715692v1.9","doi-asserted-by":"publisher","DOI":"10.1016\/j.cub.2023.08.092"},{"key":"2026040605001286000_2026.03.31.715692v1.10","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1952.sp004764"},{"key":"2026040605001286000_2026.03.31.715692v1.11","doi-asserted-by":"crossref","first-page":"729","DOI":"10.1098\/rsbl.2012.0435","article-title":"It pays to cheat: tactical deception in a cephalopod social signalling system","volume":"8","year":"2012","journal-title":"Biology letters"},{"key":"2026040605001286000_2026.03.31.715692v1.12","doi-asserted-by":"publisher","DOI":"10.1098\/rspb.1999.0786"},{"key":"2026040605001286000_2026.03.31.715692v1.13","doi-asserted-by":"publisher","DOI":"10.1016\/j.cub.2025.01.005"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.03.31.715692","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,6]],"date-time":"2026-04-06T12:00:17Z","timestamp":1775476817000},"score":1,"resource":{"primary":{"URL":"http:\/\/biorxiv.org\/lookup\/doi\/10.64898\/2026.03.31.715692"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,2]]},"references-count":13,"URL":"https:\/\/doi.org\/10.64898\/2026.03.31.715692","relation":{},"subject":[],"published":{"date-parts":[[2026,4,2]]},"subtype":"preprint"}}