Definition of "blastoderm" [blas•to•derm]

• The layer of cells that develops on the surface of the yolk in an avian or reptilian egg and gives rise to the germinal disk from which the embryo develops. (noun)
• The layer of cells formed by the cleavage of a fertilized mammalian egg. It later divides into the three germ layers from which the embryo develops. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "This white mark will be perfectly round if the egg is fertile (called a blastoderm)."
• "If vesicles are then generated from this proto-ER/Golgi, a plasma membrane can be formed on an existing cytoskeleton, a process similar to the formation of the cellular blastoderm in Drosophila and similar to the addition of vesicle to the current plasma membrane."
• "The syncytial blastoderm in Drosophila show that the nuclei can independently divide and later form a multicellular embryo."