Wednesday, 17 June 2015
Human evolution: brain, birthweight and the immune system
The Royal Society recently published a special issue of Philosophical Transactions B entitled Human evolution: brain, birthweight and the immune system, edited by Graham J Burton, Ashley Moffett and Barry Keverne. The interesting theme is summarized as follows:
"The complexity of the human brain is unique amongst mammals. However, the large size of the brain at birth poses risks to mother and offspring due to constraints on pelvic architecture and uterine perfusion imposed by bipedalism, the so-called ‘obstetric dilemma’. The growth of the human brain in utero is believed to be permitted by our unique highly invasive form of placentation. The structure of the placenta varies to a greater extent between different mammalian species than any other organ. In particular, there is a spectrum of invasiveness of the fetal tissues into the wall of the uterus, even amongst the apes. Invasion poses unique immunological challenges as the migrating trophoblast cells expressing paternal genes intermingle with cells of the maternal immune system in the uterine wall that must be negotiated. Recent advances have also revealed important insights into the genetic and epigenetic links between the regulation of placental and brain growth, centred on imprinted genes that are expressed in a parent-of-origin manner. This complex network of interactions regulating brain development is explored in this Theme Issue in the light of new concepts in placental evolution, the immune system at the maternal-fetal interface, and genomic imprinting."
The table of contents can be found here. Disclosure: I co-authored one of the papers.