The placenta is a remarkable thing: a brand new organ grown during pregnancy to pass nourishing chemicals to baby. But these new developments can make mum’s immune system suspicious, and it must learn to tolerate, rather than attack. The striking colours of these mouse placentas reveal how the immune system can affect placental development. Coloured stains pick out the same types of cell in each placenta, but differences in the immune genes of the mice change how these cells develop, producing different patterns. All the cells are highlighted in blue, while cells lining blood vessels are red, and developing placental cells are shown in green. A mixture of these produces yellows and purples and reveals, for example, that the top left placenta has fewer blood vessels. Understanding how the immune system reacts to a pregnancy could help to treat complications in placenta development, like preeclampsia, in expectant human mothers.
Written by John Ankers
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