A blastoderm (germinal disc, blastodisc) is a single layer of embryonic epithelial tissue that makes up the blastula.[1] It encloses the fluid-filled blastocoel. Gastrulation follows blastoderm formation, where the tips of the blastoderm begins the formation of the ectoderm, mesoderm, and endoderm.[2]
Formation
The blastoderm is formed when the oocyte plasma membrane begins cleaving by invagination, creating multiple cells that arrange themselves into an outer sleeve to the blastocoel.[1]
In chicken eggs, the blastoderm represents a flat disc after embryonic fertilization.[3] At the edge of the blastoderm is the site of active migration by most cells.[4]
DNA repair genes are highly expressed in chicken blastoderms.[5]
^Bellairs, Ruth; Osmond, Mark. Atlas of Chick Development (3 ed.). Atlas Press. p. 15–28.
^Rengaraj D, Won S, Jung KM, Woo SJ, Lee H, Kim YM, Kim H, Han JY. Chicken blastoderms and primordial germ cells possess a higher expression of DNA repair genes and lower expression of apoptosis genes to preserve their genome stability. Sci Rep. 2022 Jan 7;12(1):49. doi: 10.1038/s41598-021-04417-y. PMID 34997179; PMCID: PMC8741993
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