Understanding somatic cell characteristics to improve embryo developmental potential in vitro

经过20多年的研究，非家养物种体外胚胎技术的实施进展有限。用于研究目的的材料供应不足是进展缓慢的主要原因;然而，物种特异性差异（例如季节性，发育速度）导致了产生后代的挑战。此外，目前储存在世界各地生物库中的遗传物质主要由冷冻精子组成。获得和冷冻保存卵母细胞和胚胎的困难限制了这些生物库中女性遗传学的比例。我们对野牛（野牛野牛）的研究证实了该物种卵母细胞处理和培养的复杂性，卵母细胞成熟率低，使用标准的国内牛方案进行体外胚胎发育。国际自然保护联盟（自然保护联盟）最近呼吁采取行动，储存所有受威胁物种的细胞，以便在遗传物质丧失之前加以保存，这使人们对体细胞库的兴趣增加，并在世界各地开始建立体细胞库。主要原因之一是体细胞的重编程能力及其对未来后代生产的潜在用途。我们的研究表明，样本收集和培养建立技术影响成纤维细胞培养的特点，包括染色体数目和端粒长度。此外，成纤维细胞培养物中的个体差异在体细胞核移植（SCNT）后的植入前胚胎发育中发挥了重要作用，尽管这些差异的原因尚未阐明。为了使用基于体细胞的技术（如SCNT）来改善胚胎生产，需要更好地理解供体细胞的遗传和表观遗传组成，以识别并潜在地修改调节胚胎存活的因素。我们的研究兴趣在于了解细胞因子对种间SCNT胚胎早期发育的影响，以提高其在生产具有遗传价值的动物中的潜在用途。这项拟议的研究将确定成年体细胞中可能表明SCNT成功的因素，并检查供体细胞的修饰是否可以促进适当的重编程并提高早期胚胎的生存力和质量。在研究的第一阶段，木材野牛供体细胞的特性将被用来关联细胞参数与种间SCNT的成功。在第二阶段，在SCNT之前将对野牛供体细胞进行修饰，以评估它们对囊胚发育的影响。这项研究将增加我们对胚胎活力和质量的细胞决定因素的理解，并为我们提供改善国内和非国内物种SCNT结果的潜在方法。

After more than 20 years of research, there has been limited progress in the implementation of in vitro embryo technologies for non-domestic species. Insufficient supply of materials for research purposes plays a major role in the slow progress; however, species-specific differences (e.g. seasonality, rates of development) contribute to the challenges of producing offspring. In addition, genetic material currently stored in biobanks around the world consists primarily of frozen sperm. Difficulties in obtaining and cryopreserving oocytes and embryos have limited the proportion of female genetics represented in these biobanks. Our studies in bison (Bison bison) have confirmed the complexities of oocyte handling and culture in this species with low oocyte maturation and in vitro embryo development rates using standard domestic cattle protocols. A recent call to action from the International Union for the Conservation of Nature (IUCN) for the banking of cells from all threatened species to preserve genetic material before it is lost has resulted in an increased interest in somatic cell banking and the initiation of somatic cell banks around the world. One of the primary reasons is the reprogramming capability of somatic cells and their potential use for future offspring production. Our studies have shown that sample collection and culture establishment techniques influenced fibroblast culture characteristics, including chromosome number and telomere length. Furthermore, individual variability in the fibroblast cultures played a significant role in pre-implantation embryo development following somatic cell nuclear transfer (SCNT), although the reason for these differences was not elucidated. In order to improve embryo production using somatic cell-based techniques, such as SCNT, a better understanding of the genetic and epigenetic make-up of the donor cells is necessary to identify, and potentially modify, factors regulating embryo survival. Our research interest lies in understanding the influence of cellular factors on early development of interspecies SCNT embryos to improve its potential use in the production of genetically valuable animals. The proposed research will identify factors in adult somatic cells that may be indicative of SCNT success and examine whether modification of the donor cells can promote proper reprogramming and enhance early embryo viability and quality. In the first phase of the study, characterization of wood bison donor cells will be used to correlate cell parameters with interspecies SCNT success. In the second phase, modification of bison donor cells will be carried out prior to SCNT to evaluate their influence on blastocyst development. This study will increase our understanding of cellular determinants of embryo viability and quality and provide us with potential methods for improving SCNT outcomes in both domestic and non-domestic species.