Yali Liu, Meng Qu, Han Jiang, Ralf Schneider, Geng Qin, Wei Luo, Haiyan Yu, Bo Zhang, Xin Wang, Yanhong Zhang, Huixian Zhang, Zhixin Zhang, Yongli Wu, Yingyi Zhang, Jianping Yin, Si Zhang, Byrappa Venkatesh, Olivia Roth, Axel Meyer, Qiang Lin
In the highly derived syngnathid fishes (pipefishes, seadragons & seahorses), the evolution of sex-role reversed brooding behavior culminated in the seahorse lineage's male pregnancy, whose males feature a specialized brood pouch into which females deposit eggs during mating. Then, eggs are intimately engulfed by a placenta-like tissue that facilitates gas and nutrient exchange. As fathers immunologically tolerate allogenic embryos, it was suggested that male pregnancy co-evolved with specific immunological adaptations...
December 9, 2022: Nature Communications