Embryogenesis is a complex process during the first eight weeks after fertilization in which a fertilized egg develops into an embryo. The embryogenesis process can be described as the following:
Embryogenesis starts with a zygote, a single diploid cell. The zygote cell develops into an embryo with total 8 cells within the zona pellucida through mitotic divisions with no significant growth in volume (this period is known as cleavage) and cellular differentiation. The next stage is compactation involving the tight binding cells and forming a compact sphere. After compactation, a morula is forming which contains 16 cells. A cavity called the blastocele develops in the morula and secretes water into the morula and the amount of total cells reaches 40 to 150. With the degeneration of zona pellucida, blastocele becomes bigger and form a blastocyst. Then the blastocele moves and implants into the uterus. During the next week, most cells rapidly divides, forming a disc-shaped structure with two layers. One layer develops into the embryo and the amniotic cavity, while another layer becomes the yolk sac. The next stage is gastrulation and a streak of cells becomes apparent on the embryonic disc. Then two types of cells from the streak will transform the two-layered disc into a three-layered one with ectoderm, mesoderm and endoderm layers at the time of three weeks after ovulation. These layers will develop into kinds of organs and form systems of the body in later time.
These complex and surprising process is regulated by kinds of signal molecules and proteins. Here, Creative-Biomart provides powerful molecular tools associated with embryogenesis for research applications.