Hypoblast (from the Greek hypó - “below, below” and blastós - “embryo, sprout”) - the inner layer of the cell wall of the diskoblastula and blastodisc in amniotes (higher vertebrates).
The hypoblast is not homologous to the endoderm, since it contains the material mainly from the extra-germinal endoderm , and the endoderm of the embryo is formed during gastrulation by the inclusion of epiblast cells that migrate inside the embryo into the hypoblast.
In some animals, the hypoblast is separated from the outer layer ( epiblast ) by a special cavity - blastocele .
Sources
- Hypoblast - an article from the Biological Encyclopedic Dictionary.
- Hypoblast // Great Soviet Encyclopedia : [in 30 vol.] / Ch. ed. A.M. Prokhorov . - 3rd ed. - M .: Soviet Encyclopedia, 1969-1978. .