Altered cell-division rates after laser-induced cell fusion in nematode embryos.

In embryos of Caenorhabditis elegans adjacent cells belonging to different cell lines have been fused by disrupting the cell membrane between them with a single laser pulse. This leads to cytoplasmic mixing. Synchronous mitoses of the two nuclei result in the direct formation of four cells. Subsequent alteration of the cell cycle rhythm in some specific--but not all--descendants of the fused cells is observed, leading to abnormal cell patterns and often embryonic arrest.