Male seahorses suppressed immunity for pregnancy. Similarly, this mechanism works in pregnant women, but skates lose several genes during this process. A study by scientists from the Helmholtz Center for Oceanology is published in the journal Proceedings of the National Academy of Sciences.
The immune system, both in humans and in other types of living organisms, perceives the fetus developing during pregnancy as a foreign body. In the case of humans and other mammals, one of the mechanisms is the penetration of the baby’s stem cells into the bone marrow of the mother. This leads to the suppression of inflammatory activity that would occur if this did not happen.
For a more detailed study of the immune system during pregnancy, researchers focused on the study of vertebrates, in which, unlike mammals, pregnancy occurred independently more than a hundred times.
In the new work, scientists chose the needle family, which includes needlefish and seahorses. The males are responsible for pregnancy in this family – representatives of one species carry eggs on the abdomen, another protect them with skin folds, and a third carry them in a bag with an analog of the placenta.
By sequencing the genome of representatives of 14 species from the needle family, scientists found that Hippocampus and Syngnathus partially modify or completely exclude genes of the MHC mechanism, the main complex that is responsible for the fight of the immune system against a foreign object.
In addition, representatives of both of the above species resort to gene expression. Thus, in fish, as in humans, the activity of certain immune pathways decreases. However, this process occurs in different ways, the authors of the study note.