论文代写:胚胎发育

论文代写:胚胎发育

秀丽隐杆线虫胚胎在第一个细胞分裂前表现出不同的胚胎前后不对称性。包括调控蛋白质定位的胚胎极化与整个第一细胞周期中的细胞质重排有关。卵母细胞受精后,皮层细胞质向前极移动,中心物质向相反方向移动。正常情况下,线虫卵母细胞的受精发生在其前缘,并从输卵管进入受精囊(Gönczy,2005)。精子进入卵核所在的极处的卵母细胞。

论文代写:胚胎发育
后部成为精子进入的部位,在受精时含有核卵的部位形成前极。当精子从正常进入反极时,AP轴被逆转,但通常胚胎在所有其他方面发育。精子原核指导细胞质的重排,负责建立不对称性(Green,Whitener,Mohanty&Lekven,2014)。线虫精子也可以横向进入鸡蛋而不是操纵条件下的杆子。在这种情况下,精子原核运行到最后一个后极。精子的进入是建立AP轴的关键。

论文代写:胚胎发育

The C. elegans embryo demonstrates different embryonic anteroposterior asymmetries before the division of the first cell. The embryonic polarization which includes localization of the regulatory proteins is linked with the cytoplasmic rearrangement throughout the cycle of first cell. After the oocyte is fertilized, the cortical cytoplasm moves towards the anterior pole and the central materials moves in the opposite directions. Normally, the fertilization of elegans oocytes takes place at their leading edges, and they go into spermatheca from oviduct (Gönczy, 2005). The sperm enters into the oocyte at the pole where the nucleus egg is located.

论文代写:胚胎发育
The posterior becomes the site of the sperm entry, and anterior pole is formed in the region which contains nucleus egg at the fertilization time. When the sperm enters from normal to opposite pole, then the AP axis is reversed, but normally the embryo develops in all other aspects. The sperm pronucleus directs the rearrangements of cytoplasm responsible for the establishment of the asymmetries (Green, Whitener, Mohanty & Lekven, 2014). The C. elegans sperms can also enter laterally into the egg rather than at the pole in manipulated conditions. In this situation, the sperm pronucleus travels to the closest pole which becomes posterior. The entry of sperm is the key to establishing the AP axis.