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With molecular and cellular landmarks that are clearly related to but distinguishable from those found in apicomplexan parasites,\n                  <jats:italic>Chromera<\/jats:italic>\n                  provides a fantastic opportunity to investigate the evolutionary origin of the structures and processes needed for intracellular parasitism. However, tools for defining localization and functions of gene products do not exist for\n                  <jats:italic>Chromera<\/jats:italic>\n                  , which creates a major bottleneck for exploring its biology. Here we report two major advances in exploring the cell biology of this free-living relative of a large group of intracellular parasites: 1) successful cell transformation and 2) the implementation of expansion microscopy. The initial analysis enabled by these tools generated new insights into subcellular organization in different life stages of\n                  <jats:italic>Chromera.<\/jats:italic>\n                  These new developments boost the potential of\n                  <jats:italic>Chromera<\/jats:italic>\n                  as a model system for understanding the evolution of parasitism in apicomplexans.\n                <\/jats:p>","DOI":"10.1101\/2025.08.26.672290","type":"posted-content","created":{"date-parts":[[2025,8,29]],"date-time":"2025-08-29T23:25:13Z","timestamp":1756509913000},"source":"Crossref","is-referenced-by-count":0,"title":["Transfection of the free-living alga\n                  <i>Chromera velia<\/i>\n                  enables direct comparisons with its parasitic apicomplexan relative,\n                  <i>Toxoplasma gondii<\/i>"],"prefix":"10.64898","author":[{"given":"Isadonna F.","family":"Tengganu","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ke","family":"Hu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2025090301401245000_2025.08.26.672290v1.1","first-page":"F1000","article-title":"Recent advances in understanding apicomplexan parasites","volume":"5","year":"2016","journal-title":"F1000Research"},{"key":"2025090301401245000_2025.08.26.672290v1.2","doi-asserted-by":"publisher","DOI":"10.1038\/nature06635"},{"key":"2025090301401245000_2025.08.26.672290v1.3","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1003335107"},{"key":"2025090301401245000_2025.08.26.672290v1.4","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1423790112"},{"issue":"2","key":"2025090301401245000_2025.08.26.672290v1.5","doi-asserted-by":"crossref","first-page":"444","DOI":"10.1038\/ismej.2012.129","article-title":"Environmental distribution of coral-associated relatives of apicomplexan parasites","volume":"7","year":"2013","journal-title":"ISME J"},{"issue":"2","key":"2025090301401245000_2025.08.26.672290v1.6","first-page":"306","article-title":"Morphology, ultrastructure and life cycle of Vitrella brassicaformis n. sp","volume":"163","year":"2012","journal-title":", n. gen., a novel chromerid from the Great Barrier Reef. 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