Embryonic development in the womb is a complicated process that is still puzzling today. In particular,researchers have not determined how the paternal genetic information present in the embryo are tolerated by the maternal immune system and not rejected upon recognition as foreign. While this process is now well understood in humans, pregnancies in the animal kingdom still provoke many unanswered questions. An international team under the leadership of the GEOMAR Helmholtz Centre for Ocean Research Kiel has intensively studied the unique phenomenon of male pregnancy in 12 species of pipefishes and seahorses. In some species, the males carry the eggs only on their trunk; in others, they protect the eggs within skin flaps or even placenta-like systems that supply the offspring with nutrients and oxygen.
Click here for original story, Immune system alteration identified as key process in the male pregnancy of seahorses
Source: Phys.org