PHLDA2 immunohistochemistry in the tammar yolk sac placenta. Both bilaminar and trilaminar yolk sac membranes are shown as the cord like structure in the sections (A: bilaminar yolk sac, B: trilaminar yolk sac). "T" indicates trophoblast cells, the large cells with large nuclei, and "En" indicates yolk sac endodermal cells, the flat and thin cells with relatively small nuclei.
Suzuki et al. BMC Evolutionary Biology 2011 11:244 doi:10.1186/1471-2148-11-244