Developmental Biology 卵母细胞A一P极性的确定 Antero-posterior axis specification Fig. 5. 12 Specification of the antero- nurse cell posterior and dorso-ventral axes during Drosophila oogenesis. The oocyte moves to the posteror end of -Nucleus the egg chamber and comes into contact with the polar follicle cells, It is separated uncommitted from follicle cells at the anterior end polar follicle cells Oocyte Polar foale cei secreted locally. The binding ot the 59 (blue) by the nurse cells. gurken mRNA Is synthesized and the gurken prot microtubules protein to the torpedo receptor protein Dorso-ventral axis specification on the adjacent follicle cell initiates their specification as posterior polar follicle cells(yellow). They send a signal back to the oocyte that reorganizes the oocyte cytoskeleton(green microtubules). This directs the localization of the bicoid and anterior poster oskar proteins to the antenor and postenor ends of the oocyte, respectively. thus detining the antero-posterior axis Subsequent movement of the nucleus dorsal follicle cells toward the future dorsal side and the ∈D∈ bicoid mRNA gurken local release of gurken protein then elease specifies the adjacent follicle cells as dorsal follcle cells and that side of the oocyte as the future dorsal side. After Gonzales. Reyes, A. et al.: 1995 oskar mRNA ventral follicle ce is
Developmental Biology 卵母细胞A－P极性的确定
Developmental Biology 卵母细胞DV极性的确定 POooooool I Dorsal Tol tO protein follicle 888 在受精前腹部的卵泡细 synthesis Spatzle Activated 胞合成Pipe、 Windbeutel Nudel,定位在腹部卵外膜 Windbeutel, NudeL P 。,=上,受精后经一系列反应, Acmm最终使卵周质腹部区的 Dorsa蛋白释放进入核中, windbeutel Nudel Pipe envelope w启动腹部特异性基因的表 达 Figure 14.38 Schematic representation of a model for 1, Oocyte nucleus travels to anterior 5. Ventral follicle cells synthesize windbeutel the generation of the dorsal-ventra del, and Pipe proteins larity in Drosophila. (A)The oocyte of l5 nurse cells (which supply mater 2 frmmichte ar e ckrken ssages splitting of Easter zymogen, making active nal proteins and messages to the devel- Easter protease only on ventral side oping egg)and follicle cells.(B)The during mid-oogenesis 7, Easter splits Spatzle, which binds to will become the dorsal side. The corni. 3a. Torpedo signal causes follicle cells to loll receptor protein chon and gurken genes of the oocy syn- differentiate to a dorsal morphology 8. Toll signal causes phosphorylation and thesize a signal that is received by the 3b. Synthesis of Windbeutel, Nudel, and gradation of Cactus protein. receptor made by the torpedo gene of th roteins inhibited in dorsal follicle cells llicle cells Given the short diffusibili- 4. Conichon and Gurken proteins do not closest to the ooo hi w the follicle cel 9. Dorsal protein enters the nucleus and of the signal, only t diffuse to ventral side centralizes the cell yte nucleus (i.e, the
Developmental Biology 在受精前腹部的卵泡细 胞合成 Pipe、Windbeutel、 Nudel，定位在腹部卵外膜 上，受精后经一系列反应， 最终使卵周质腹部区的 Dorsal蛋白释放进入核中， 启动腹部特异性基因的表 达 。 卵母细胞D－V极性的确定