Biparental haploid cells to generate genomically designed offspring

在自然选择中，差异适应度依赖于减数分裂期间的染色体洗牌，从而产生遗传上不同的单倍体配子。然而，减数分裂引起的遗传变异对动物养殖业来说是一个经济负担，因为后代往往不能从父母那里继承最理想的基因。虽然基因组标记目前被用于在出生时甚至更早的时候识别优秀的后代，但动物或胚胎经常因为没有从父母那里继承最好的基因而被淘汰。该项目旨在通过在受精前确定亲本配子的基因组价值来消除牛育种计划中的减数分裂不确定性。将产生卵子和精子来源的单倍体细胞，并对其进行分析，以识别携带优越基因组的细胞以产生后代。该项目提案分为三个目标：(1)优化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，用于二倍体化；(2)制定胚胎细胞系增殖方案，获得无限量的单倍体细胞进行二倍体化；(3)利用基因组特征的单性和孤雌单倍体细胞获得具有双亲预定基因组的二倍体胚胎和可存活的后代。该提案得到了SEMEX的财政和科学支持，SEMEX是加拿大和国际上牛遗传学的主要工业参与者。预先确定遗传优势父母后代基因组的能力将为SEMEX提供一个独特的技术平台，将其纳入其选择计划，并在全球范围内提供相当大的竞争优势。此外，一名博士后、一名博士生和SEMEX的研究团队之间最先进的科技交流，有望为培养加拿大高需求领域的HQP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.