primitive streaks การใช้

• This separation is crucial in the formation of the primitive streak.
• At the end of the second week, a primitive streak appears.
• The absence of hypoblast results in multiple primitive streaks in chicken embryos.
• Avian gastrulation occurs as cells move though the primitive streak.
• Hence, primitive streak is analogous to the blastopore lip in amphibian gastrulation.
• The primitive streak is key in the development of the major body axes.
• The primitive streak develops from Koller s sickle and the epiblast of the avian embryo.
• They are derived from the posterior primitive streak region of the mesoderm in the gastrulating embryo.
• The tissue undergoes convergent extension as the primitive streak regresses, or as the embryo gastrulates.
• When the primitive streak forms, these cells expand out to become Hensen's node.
• In chicken and mouse, Vg1 and Nodal respectively promote primitive streak formation in the epiblast.
• Similarly, the posterior cells of Koller s sickle form the posterior region of the primitive streak.
• Within birds and mammals, epiblast cells converge at the midline and ingress at the primitive streak.
• The formation of the primitive streak, through which gastrulation occurs, is induced by Koller's sickle.
• As the cells of Koller s sickle migrate during gastrulation, they form different portions of the primitive streak.
• Callebaut and Van Nueten observed the formation of a normal secondary primitive streak, mesoderm, and definitive endoderm.
• Amphioxus forms an epithelial neural tube and dorsal notochord but does not have the EMT potential of the primitive streak.
• Even after implantation begins, a preembryo ( and proembryo ) may exist up until formation of the primitive streak.
• Research can only be performed on an embryo for a maximum of fourteen days or until the primitive streak appears.
• The neural plate will form opposite the primitive streak from ectodermal tissue which thickens and flattens into the neural plate.