Viruses in Human Pregnancy
In the year 2000 we discovered the first human endogenous retrovirus (HERV) that fused human cells to form the normal placenta. You see it as the dark blue staining around the edges of the placental finger-like processes on the illustration above. In 2002 we discovered a second virus that helped to prevent the maternal immune rejection of the human foetus in the womb. Today we know of 8 different viruses within our genome that play an important role in human pregnancy.
Viruses in Human Embryology
Viruses play a key role in the formation of vital structures in foetal development, including the brain, heart, kidneys, liver, tongue, adrenal glands, and adipose tissue - and this study of the role of viruses in human embryology has just begun
How did these viruses come to be part of us?
Illustration: kind courtesy of Dr John McCoy