Genetics and imaging to assess oocyte and preimplantation embryo health.
Genetics and imaging to assess oocyte and preimplantation embryo health.
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用于评估卵母细胞和植入前胚胎健康状况的遗传学和成像。
DOI：
10.1071/rd04088
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
DiMarzio,CA
中科院分区：
文献类型：
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作者：
Warner,CM;Newmark,JA;Comiskey,M;DeFazio,SR;O'Malley,DM;Rajadhyaksha,M;Townsend,DJ;McKnight,S;Roysam,B;Dwyer,PJ;DiMarzio,CA
目前在人类辅助生殖技术（ART）中使用两个主要标准来评估卵母细胞和植入前胚胎健康：（1）植入前胚胎发育率;和（2）总体形态。调控着床前发育速率的一个主要基因是我们实验室发现的着床前胚胎发育（Ped）基因。在小鼠中，Ped基因产物Qa-2蛋白的存在导致快速的植入前胚胎发育，相比之下，缺乏Qa-2蛋白的胚胎的植入前胚胎发育速度较慢。此外，表达Qa-2蛋白的小鼠具有超出植入前时期的整体生殖优势，包括更高的出生存活率，更高的出生体重和更高的断奶存活率。数据表明，Qa-2作为一种细胞信号分子增加早期胚胎的发育速率，磷脂酰肌醇-3 ′激酶参与细胞信号通路。Qa-2最可能的人类同源物最近被鉴定为人类白细胞抗原（HLA）-G。数据显示，HLA-G，像Qa-2，位于脂筏，这意味着HLA-G也作为一个信号分子。为了更好地评估ART中使用的第二个标准（即整体形态），已经构建了一种独特的创新成像显微镜，即Keck 3D融合显微镜（Keck 3DFM）。Keck 3DFM将五种不同的显微模式结合到一个平台中，允许对样品进行多模式成像。其中一种模式，正交层析显微镜（QTM），通过测量折射率的变化来创建未染色透明细胞的数字图像。首次报道了小鼠卵母细胞和植入前胚胎的正交断层显微镜图像。来自QTM图像的数字信息应该允许非侵入性地计数植入前胚胎中的细胞数量。Keck 3DFM也被用于通过使用k-means聚类算法评估小鼠卵母细胞和胚胎中的线粒体分布。着床前胚胎细胞数量和线粒体分布与卵母细胞和胚胎健康有关。从Keck 3DFM获得的新成像数据，结合遗传和生物化学方法，有望以非侵入性方式区分健康与不健康的卵母细胞和胚胎。我们的目标是将我们的小鼠模型系统的信息应用于临床，以识别一个且只有一个健康的胚胎，并将其移植回接受ART手术的母亲。这种方法有可能提高ART的成功率，并降低目前与ART相关的高且不受欢迎的多胎出生率。
Two major criteria are currently used in human assisted reproductive technologies (ART) to evaluate oocyte and preimplantation embryo health: (1) rate of preimplantation embryonic development; and (2) overall morphology. A major gene that regulates the rate of preimplantation development is the preimplantation embryo development (Ped) gene, discovered in our laboratory. In mice, presence of the Ped gene product, Qa-2 protein, results in a fast rate of preimplantation embryonic development, compared with a slow rate of preimplantation embryonic development for embryos that are lacking Qa-2 protein. Moreover, mice that express Qa-2 protein have an overall reproductive advantage that extends beyond the preimplantation period, including higher survival to birth, higher birthweight, and higher survival to weaning. Data are presented that suggest that Qa-2 increases the rate of development of early embryos by acting as a cell-signalling molecule and that phosphatidylinositol-3′ kinase is involved in the cell-signalling pathway. The most likely human homologue of Qa-2 has recently been identified as human leukocyte antigen (HLA)-G. Data are presented which show that HLA-G, like Qa-2, is located in lipid rafts, implying that HLA-G also acts as a signalling molecule. In order to better evaluate the second criterion used in ART (i.e. overall morphology), a unique and innovative imaging microscope has been constructed, the Keck 3-D fusion microscope (Keck 3DFM). The Keck 3DFM combines five different microscopic modes into a single platform, allowing multi-modal imaging of the specimen. One of the modes, the quadrature tomographic microscope (QTM), creates digital images of non-stained transparent cells by measuring changes in the index of refraction. Quadrature tomographic microscope images of oocytes and preimplantation mouse embryos are presented for the first time. The digital information from the QTM images should allow the number of cells in a preimplantation embryo to be counted non-invasively. The Keck 3DFM is also being used to assess mitochondrial distribution in mouse oocytes and embryos by using the k-means clustering algorithm. Both the number of cells in preimplantation embryos and mitochondrial distribution are related to oocyte and embryo health. New imaging data obtained from the Keck 3DFM, combined with genetic and biochemical approaches, have the promise of being able to distinguish healthy from unhealthy oocytes and embryos in a non-invasive manner. The goal is to apply the information from our mouse model system to the clinic in order to identify one and only one healthy embryo for transfer back to the mother undergoing an ART procedure. This approach has the potential to increase the success rate of ART and to decrease the high, and undesirable, multiple birth rate presently associated with ART.