vegetal pole การใช้

• This polar lobe forms at the vegetal pole during cleavage, and then gets shunted to the D blastomere.
• The animal pole consists of small cells that divide rapidly, in contrast with the vegetal pole below it.
• It is thought that these contacts allow the YSL to " tow " the EVL towards the vegetal pole.
• The vegetal pole contains large yolky cells that divide very slowly, in contrast with the animal pole above it.
• The cytoplasm in the vegetal pole specifies this axis and removing this cytoplasm leads to a loss of axis information.
• This layer forms when the cells at the vegetal pole of the blastoderm combine with the yolk cell underneath it.
• The axis of symmetry passes through on one side the animal pole, and on the other side the vegetal pole.
• The blastoderm begins to thin as it spreads toward the vegetal pole of the embryo until it has completely engulfed the yolk cell.
• The YSL also moves towards the vegetal pole, spreading along the surface of the yolk and migrating slightly ahead of the blastomeres.
• The anterior / posterior axis lies along the animal / vegetal axis set up during nuclei at the vegetal pole of the blastula.
• The pole of the egg with the highest concentration of yolk is referred to as the vegetal pole while the opposite is referred to as the animal pole.
• The egg cell is generally asymmetric, having an " animal pole " ( future ectoderm and mesoderm ) and a " vegetal pole " ( future endoderm ).
• To identify these elements, researchers looked for mRNA and protein that demonstrated localization to either the vegetal pole or the dorsal side of the embryo to find candidates.
• All bilaterian animals at an early stage of development form a gastrula, which is polarized, with one end called the animal pole and the other the vegetal pole.
• Wnt 11 was found to be located specifically at the vegetal pole prior to cortical rotation and is moved to the dorsal side where it activates the wnt signaling pathway.
• Because cleavage is impeded in the vegetal pole, there is a very uneven distribution and size of cells, being more numerous and smaller at the animal pole of the zygote.
• As in Xenopus, mesoderm induction involves two signals : one from the vegetal pole to induce ventral mesoderm and one from the Nieuwkoop center equivalent dorsal vegetal cells to induce dorsal mesoderm.
• However, in cnidarians the depression forms at the end further from the yolk ( at the animal pole ), while in bilaterians it forms at the other end ( vegetal pole ).
• In some cases, the vegetal pole is thought to differentiate into the extraembryonic membranes that protect and nourish the developing embryo, such as the placenta in mammals and the chorion in birds.
• The high nuclear levels of b-catenin results from the high accumulation of the "'disheveled protein "'at the vegetal pole of the egg . disheveled inactivates GSK-3 and prevents the phosphorylation of ?-catenin.