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。由于来自稀有或外来动物的卵母细胞不足以作为外来供体细胞核的受体，因此在非家养物种中使用种间SCNT进行胚胎生产是必要的。这些胚胎发育不良到足月妊娠表明它们发育受损。供体细胞核和受体细胞质之间的不相容性被认为在发育下降中起重要作用。我们的研究兴趣在于阐明在种间核细胞质相互作用中被破坏的机制，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。线粒体在细胞通路（能量产生、细胞凋亡）中发挥核心作用，这是细胞正常功能所必需的。线粒体生物发生、功能和分布的失调导致mtDNA拷贝数、ATP水平和细胞凋亡率的改变，所有这些都与早期胚胎骤停和死亡有关。细胞质与核基因组和中心体之间的相互作用是维持正常线粒体活性的关键，中心体是遗传自不相关的供体细胞的组成部分。该研究将研究在进化相似的牛种SCNT胚胎中，涉及线粒体分布和功能的核-胞质相互作用是否被破坏。美国野牛（Bison Bison）和家牛（Bos taurus）配子和体细胞将通过体外受精（IVF）和SCNT技术产生杂交胚胎。对这些独特杂交种的分析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。这对于非家养物种体外胚胎生产方案的开发和优化至关重要。

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.