part of epithelial cell morphogenesis embryonic morphogenesis branching involved in labyrinthine layer morphogenesis epithelial cell differentiation involved in embryonic placenta development epithelial cell morphogenesis involved in placental branching The change in form (cell shape and size) that occurs when a trophoblast cell elongates to contribute to the branching of the placenta. biological_process dph GO:0060672 2009-06-02T12:44:52Z