两步极体活检对小鼠卵母细胞体外受精和胚胎发育的影响

发布时间：2018-10-16 14:28

【摘要】：为避免产前诊断如绒毛活检或羊水诊断所致选择性流产,提出了植入前遗传学诊断(preimplantation genetic diagnosis, PGD)的思想,目前已广泛用于基因或染色体异常高风险夫妇的遗传学筛查。大多通过卵裂球活检进行遗传学分析和诊断,选择正常无遗传缺陷的胚胎移植入子宫以生育健康的后代。但胚胎染色体非整倍体嵌合率较高,可导致误诊。卵裂球活检是对胚胎本身进行操作,具有高度侵入性。为避免卵裂期胚胎活检可能对胚胎发育能力的影响,提出了用第一极体(the first polar body, 1PB)分析的思想以预测卵母细胞的基因型。由于减数分裂时染色体重组,约半数1PB可能为杂合子。如果不同时检测第二极体(the second polar body, 2PB),大量来自1PB检测后诊断为杂合子的卵母细胞的胚胎的基因型不能预测。为了确保第二次减数分裂后形成的半合子正常卵细胞能被检测并挑选出来,又引入了2PB分析以完善极体诊断。极体在胚胎发育和合子形成中是非必需的,它不引起胚胎成分的减少,去除极体应该不影响卵子受精和胚胎正常发育。目前PGD的安全性仍是人们广泛关注的问题,卵裂球活检的安全性和可靠性已得到认同并广泛用于PGD。极体活检特别是两步极体活检是否影响胚胎发育以及与卵裂球活检比较是否更安全,国内尚未见报道。一种新型的1.48μm红外线二极管激光仪(OCTAX-LaserShot)通过光学镜头以“非接触”的方式发生作用,近年来开始用于PGD,是一种更快捷、更简便、更安全的活检辅助工具。本研究通过动物实验比较不同极体活检方案对胚胎发育的影响以及与卵裂球活检比较评价两步极体活检的安全性,以估计对临床应用的安全性,并确定最佳活检方案为临床应用提供理论依据。
[Abstract]:In order to avoid selective abortion caused by prenatal diagnosis such as villi biopsy or amniotic fluid diagnosis, the idea of preimplantation genetic diagnosis of (preimplantation genetic diagnosis, PGD) has been put forward. It has been widely used in genetic screening of couples with high risk of gene or chromosome abnormality. Most of the embryos were genetically analyzed and diagnosed by cleavage biopsy, and the normal embryos without genetic defects were transferred into the uterus to produce healthy offspring. But the rate of chromosomal aneuploidy chimerism is high, which can lead to misdiagnosis. Blastomere biopsy is a highly invasive operation of the embryo itself. In order to avoid the possible effect of cleavage embryo biopsy on embryonic development ability, the idea of first polar body (the first polar body, 1PB) analysis was proposed to predict the genotype of oocytes. Due to chromosome recombination during meiosis, about half of 1PB may be heterozygotes. If the second polar (the second polar body, 2PB was not detected at the same time, the genotypes of a large number of embryos from oocytes diagnosed as heterozygotes after 1PB testing could not be predicted. In order to ensure that the normal egg cells formed after the second meiosis can be detected and selected, 2PB analysis was introduced to improve the diagnosis of polar bodies. Polar body is not necessary in embryo development and zygote formation, it does not cause the decrease of embryo composition, and the removal of polar body should not affect fertilization and normal development of embryo. At present, the safety of PGD is still a widespread concern. The safety and reliability of cleavage biopsy have been recognized and widely used in PGD.. Whether polar body biopsy, especially two-step polar body biopsy, affects embryo development and whether it is safer than cleavage biopsy has not been reported in China. A new type of 1.48 渭 m infrared diode laser (OCTAX-LaserShot) works through optical lens in a "contactless" manner. In recent years, it has been used in PGD, as a faster, simpler and safer biopsy aid. In this study, the effects of different polar body biopsy schemes on embryo development and the safety of two-step polar body biopsy were compared with those of blastomere biopsy in order to estimate the safety of clinical application. The optimal biopsy scheme was determined to provide theoretical basis for clinical application.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2005
【分类号】：R321

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