【摘 要】
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The yolk sac is a membranous sac attached to an embryo, providing early nourishment in the form of yolk in bony fishes, sharks, reptiles, birds, and primitive mammals.It functions as the developmental
【机 构】
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Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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The yolk sac is a membranous sac attached to an embryo, providing early nourishment in the form of yolk in bony fishes, sharks, reptiles, birds, and primitive mammals.It functions as the developmental circulatory system of the human embryo, before internal circulation begins.It was known that the yolk sac is the first site of hematopoiesis during mammalian development.
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