Send to

Choose Destination
Ann N Y Acad Sci. 2012 Oct;1271:97-103. doi: 10.1111/j.1749-6632.2012.06726.x.

Diversification and conservation of the extraembryonic tissues in mediating nutrient uptake during amniote development.

Author information

Lab for Early Embryogenesis, RIKEN Center for Developmental Biology, Kobe, Hyogo, Japan.


The transfer of nutrients from the mother through the chorioallantoic placenta meets the nutritional needs of the embryo during human prenatal development. Although all amniotes start with a similar "tool kit" of extraembryonic tissues, an enormous diversity of extraembryonic tissue formation has evolved to accommodate embryological and physiological constraints unique to their developmental programs. A comparative knowledge of these extraembryonic tissues and their role in nutrient uptake during development is required to fully appreciate the adaptive changes in placental mammals. Here, we offer a comparative embryological perspective and propose that there are three conserved nutrient transfer routes among the amniotes. We highlight the importance of the yolk sac endoderm, thought to be a vestigial remnant of our amniote lineage, in mediating nutrient uptake during early human development. We also draw attention to the similarity between yolk sac endoderm-mediated and trophectoderm-mediated nutrient uptake.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center