【摘要】 卵母细胞胞质中存在着大量的母源性信息,正常受精卵的发育启动和早期卵裂主要由这些母源性信息所控制。为了评估卵胞质含量对早期胚胎发育的影响,以假显微注射兔原核胚为对照,采用显微注射技术将兔原核期胚胎去除或增加一定量的细胞质:试验一,增加5%和20%的细胞质;试验二,移入5%小鼠MⅡ期卵母细胞胞质。胚胎经显微操作后进行R1/R2序贯培养。结果显示,(1)增量5%组胚胎的2细胞胚(72.00%)、8细胞胚(60.00%)、桑椹胚(58.00%)和囊胚(54.00%)的发育率均显著(P<0.05)高于增量20%组胚胎(分别为47.62%、35.71%、33.33%和30.95%),但与对照组之间无显著差异(P>0.05);囊胚细胞数在2个增量组和对照组3者之间也无显著差异(P>0.05)。(2)将5%小鼠M期卵胞质移入兔原核胚后,各阶段胚胎发育率和囊胚细胞数与增量5%组、对照组相比均无显著差异;早期胚胎经PCR检测,在2细胞胚(5/5)、8细胞胚(5/5)和桑椹胚(5/5)均全部检测到了供体小鼠mtDNA的D-loop区3′端片段,而在囊胚却仅有1枚(1/5)能够检测到。结果表明,增加少量细胞质不会对兔原核胚的体外发育造成显著影响,但胚胎发育率随着细胞质体积的增加有下降趋势,而异种卵胞质对兔原核胚的发育没有明显影响,在囊胚期虽仍能检测到异种卵胞质中mtDNA的存在,但异种mtDNA会随胚胎发育而逐渐减少。更多还原

【Abstract】 A great deal of maternal information in oocyte cytoplasm, the start of zygote development and early cleavage are mainly controlled by these information. In order to evaluate the effects of quantity of ooplasm on early embryo development, microinjection was performed to transfer a small amount of ooplasm from or to the embryo in pronuclear stage. In test 1(homogeneous ooplasmic transfer),5% or 20% of rabbit ooplasm were transferred to the rabbit pronuclear embryos, in test 2(heterogeneous ooplasmic transfer), 5% cytoplasm of mouse oocyte at meaphase Ⅱ (MⅡ) stage were transferred to the rabbit embryos; then, sequential cultured the embryo with R1/R2 . The results were as follows: Significant difference (P<0.05) was examined in the ratio of embryo developed to 2-cell stage (72.00% VS 47.62%), 8-cell stage(60.00% VS 35.71%), morula stage (58.00% VS 33.33%) and blastocyst stage (54.00% VS 30.95%) between the group increased 5% ooplasm and group increased 20% ooplasm, but no difference (P>0.05) was observed between group 5%(+) and the control group and no difference (P>0.05)was observed in cell number of morula among 5%(+) and 20%(+) and the control group. In test 2, no significant difference (P>0.05) was obversed in embryo development to each stage and the cell number of blastocyst between the group increased 5% cytoblast from mouse MⅡ oocyte and the control group. The segment of 3′ of D-loop of mouse mtDNA was tested in rabbit embryo at 2-cell stage(5/5), 8-cell stage(5/5) and morula stage(5/5),but only one was tested in blastocyst (1/5).These results suggested that, although increasing a little ooplasm has no effect on the development of the pronuclear embryo, with the volume of cytoplasm transferred increased, the ratio of the embryo development presented a decreasing tendency. Heterogeneous ooplasmic transfer has no effect on the development of the pronuclear embryo, in spite of the heterogenic mtDNA existed in blastocyst stage, but the heterogenic mtDNA would decrease gradually with the development of embryos.更多还原