Species-specific determinants of bison somatic cell nuclear transfer embryo development

体细胞核移植（SCNT）技术为保存有价值的个体和物种的遗传物质提供了一种独特的选择。由于稀有或外来动物的卵母细胞数量不足，无法作为外来供体核的受体，因此必须使用种间SCNT生产非家养物种的胚胎。这些胚胎到足月妊娠的发育不良表明它们在发育上受到了损害。供体细胞核和受体细胞质之间的不相容性被认为在发育迟缓中起重要作用。我们的研究兴趣在于阐明在种间核质相互作用过程中被破坏的机制，以确定在没有技术相关问题的情况下发育能力下降的原因。迄今为止的研究已经证明了细胞质组成和组织在SCNT胚胎成功中的重要性。线粒体在正常细胞功能所必需的细胞途径（能量产生、凋亡）中发挥核心作用。线粒体生物发生、功能和分布的失调导致mtDNA拷贝数、ATP水平和凋亡率的改变，所有这些都与早期胚胎停滞和死亡有关。细胞质与核基因组和中心体（从无关供体细胞遗传的组分）之间的相互作用对于维持正常的线粒体活性至关重要。拟议的研究将检查是否参与线粒体分布和功能的核质相互作用在进化相似的牛种的种间SCNT胚胎中被破坏。将使用野牛（野牛野牛）和家养牛（Bos taurus）的配子和体细胞，通过体外受精（IVF）和SCNT技术生产杂交胚胎。分析这些独特的杂种将使我们更好地了解细胞核和细胞质对胚胎发育的贡献的基本差异。这对于开发和优化非家养物种的体外胚胎生产方案至关重要。

Somatic cell nuclear transfer (SCNT) technology provides a unique alternative for the preservation of genetic material from valuable individuals and species. The use of interspecies SCNT for the production of embryos in non-domestic species is necessary due to insufficient quantities of oocytes from rare or exotic animals as recipients for the exotic donor nucleus. Poor development of these embryos to term-gestation suggests that they are developmentally compromised. Incompatibility between the donor nucleus and recipient cytoplasm is thought to play an important role in the decreased development. Our research interest lies in elucidating the mechanisms that are disrupted during interspecific nuclear-cytoplasmic interactions to identify the reasons for decreased developmental competence in the absence of technique-related problems. Studies to date have documented the importance of cytoplasmic composition and organization in SCNT embryo success. Mitochondria play a central role in cellular pathways (energy production, apoptosis) that are necessary for proper cell function. Dysregulation of mitochondrial biogenesis, function and distribution results in alterations in mtDNA copy number, ATP levels and rates of apoptosis, all of which have been associated with early embryo arrest and death. Interactions between the cytoplasm and the nuclear genome and centrosomes, components inherited from the unrelated donor cell, are critical for maintaining normal mitochondrial activity. The proposed research will examine whether nuclear-cytoplasmic interactions involved in mitochondrial distribution and function are disrupted in interspecific SCNT embryos from evolutionarily similar cattle species. Bison (Bison bison) and domestic cattle (Bos taurus) gametes and somatic cells will be used to produce hybrid embryos using in vitro fertilization (IVF) and SCNT techniques. Analysis of these unique hybrids will give us a better understanding of the basic differences in nuclear and cytoplasmic contribution to embryo development. This is essential for the development and optimization of in vitro embryo production protocols for non-domestic species.