Biparental haploid cells to generate genomically designed offspring

在自然选择中，差异适合度依赖于减数分裂过程中的染色体洗牌，这使得遗传上不同的单倍体配子的产生成为可能。然而，减数分裂引起的遗传变异可能会给动物养殖业带来经济负担，因为后代往往不会从父母那里继承最可取的基因。尽管基因组标记目前被用来在出生时甚至更早识别出更好的后代，但动物或胚胎经常因为没有继承父母最好的基因而被淘汰。该项目旨在通过在受精前确定双亲配子的基因组值来消除牛育种项目中减数分裂的不确定性。将产生卵母细胞和精子来源的单倍体细胞，并对其进行分析，以识别那些携带优势基因组的细胞，以产生后代。该项目建议分为三个目标：(1)优化用于二倍化的具有基因组特征的牛单倍体孤雌生殖(卵母细胞来源)胚胎细胞的生产；(2)制定胚胎细胞系倍增方案，以获得用于二倍化的无限数量的单倍体细胞；(3)使用具有基因组特征的雄核和孤雌生殖单倍体细胞来获得二倍体胚胎和具有双亲预定基因组的可存活后代。这项提议得到了加拿大和国际上牛遗传学的主要行业参与者Semex的资金和科学支持。预先确定来自遗传优势父母的后代基因组的能力将为Semex提供一个独特的技术平台，将其纳入他们的选择计划，并在全球范围内提供相当大的竞争优势。此外，一名博士后、一名博士后和Semex研究团队之间最先进的科学和技术交流预计将对加拿大需求较高地区的HQP培训做出重大贡献。

In natural selection, differential fitness relies on the chromosomal shuffling during meiosis that enables the production of haploid gametes that are genetically different. However, meiotic-induced genetic variability can be an economic burden to the animal breeding industry since offspring often do not inherit the most desirable genes from their parents. Although genomic markers are currently being used to identify superior offspring at birth or even sooner, animals or embryos are frequently culled for not inheriting the best genes from their parents. This project is aimed at eliminating meiotic uncertainty from cattle breeding programs by determining the genomic value of both parental gametes before fertilization. Oocyte and sperm-derived haploid cells will be produced and analyzed to identify those carrying a superior genome to generate offspring. The project proposal is divided into 3 objectives: (1) Optimize the production of genomically characterized bovine haploid parthenogenetic (oocyte-derived) embryonic cells for use in diploidizations; (2) Develop protocols to multiply embryonic cell lines for obtaining unlimited quantities of haploid cells for diploidization; (3) Use genomically characterized andro- and parthenogenetic haploid cells to derive diploid embryos and viable offspring with biparental predetermined genomes. The proposal is financially and scientifically supported by SEMEX, a major industrial player in cattle genetics in Canada and internationally. The ability to predetermine the genome of offspring derived from genetically superior parents will provide SEMEX with a unique technical platform to incorporate into their selection programs and provide a considerable competitive advantage worldwide. Moreover, state-of-the-art scientific and technical exchanges between a postdoctoral fellow, a PhD student and SEMEX's research team is expected to contribute significantly to training of HQP in areas in high demand for Canada.