The process of embryogenesis begins when an egg or ovum is fertilized by a sperm cell to form a zygote. This zygote then undergoes mitotic division, a process that does not result in any significant ...

While both species' blastula cells express the pou5 gene, a key stem cell regulator, the gene is not expressed in neural crest stem cells in lampreys. Losing this factor may have limited the ability ...

Reviewed by Michael Greenwood, M.Sc. Fertilization is defined as a process where gametes (an egg and sperm) join together to form a full zygote. Both the sperm and egg contain a single set of 23 ...