Researchers from Taiwan found that skin cells (superficial epithelial cells) in zebrafish undergo a new kind of cel division without DNA replication (无合成分裂) to expand body surfaces. The mother cell can actually divide 2x to produce 4 progeny cells, in which there is no intact DNA.
The paper has been published in Nature and there are extensive supplementary data and videos. Image analysis tools were also provided. The reported multicolour cell membrane tagging system (palmskin) also seems very powerful.