New story out in PNAS: Evolution of male pregnancy associated with remodeling of canonical vertebrate immunity in seahorses and pipefishes

A recently published paper led by Olivia Roth (GEOMAR; Kiel) together with several members of CEES uncovers a modification of the adaptive immune repertoire of seahorses and pipefish that coincide with evolution of male pregnancy.

Seahorse. Photo by Olivia Roth (GEOMAR; Kiel).

Seahorse. Photo by S. Kaehlert, GEOMAR.

Pregnancy evolution has required drastic adaptations to immunologically tolerate the non-self-embryo. As such, mammals suppress the expression of both major histocompatibility complex pathways (MHC I and II) to prevent embryo rejection.

These fishes display a gradient of “male pregnancy” – from external oviparity to internal gestation – and thus, represent an unique opportunity to investigate the coevolution of
immunological tolerance and male pregnancy.

Comparative immunogenomics revealed that the pipefish genus has completely lost the MHC II pathway accompanied with a diversified MHC I gene repertoire, whereas seahorses show a markedly diverged and non-functional MHC II pathway. The research team uncovered that on short evolutionary time scales remodelling of adaptive immunity has taken distinct routes to achieve immunological tolerance. This immunological flexibility calls for re-assessment of vertebrate immunity, and can improve our understanding of immune-deficiency diseases.

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Published Apr. 14, 2020 5:11 PM - Last modified Apr. 14, 2020 7:05 PM