Reproduction Abstracts

Haploid cells are amenable for genetic analysis because they contain only one set of chromosomes. Haploid cells usually exist in simple organisms, such as the budding yeast and fern, leaving an intriguing question of whether haploid cell lines in be established in mammalian systems. Here, we report that the generation of mouse haploid embryonic stem cells (haESCs) via androgenetic blastocysts and monkey haESCs via parthenogenetic blastocysts.

Mouse and rogenetic blastocyst-derived haESCs, designated as AG-haESCs, partially maintain paternalimprints, express classical ESC pluripotencymarkers, and contribute to various tissues, including the germline, upon injection into diploid blastocysts. Strikingly, live mice can be obtained upon injection of AG-haESCs into MII oocytes, and these mice bearhaESC-carried genetic traits and develop into fertile adults. Furthermore, gene targeting via homologousre combination is feasible in the AG-haESCs. These results demonstrate that AG-haESCs can be used as a genetically tractable fertilization agent for the production of live animals via injection into oocytes¹.

We then derive haESCs from parthenogenetic blastocysts of Macaca fascicularis monkeys. These cells, termed as PG-haESCs, are pluripotent and can differentiate to cells of three embryonic germ layers in vitro or in vivo. Interestingly, the haploidy of one monkey PG-haESC line (MPH1) is more stable compared with that of the other one (MPH2), as shown by the existence of haploid cells for more than 140 days without fluorescence-activated cell sorting (FACS) enrichment of haploid cells.

Importantly, transgenic monkey PG-haESC lines can be generated by lentivirus- and piggyBac transposon-mediatedgene transfer. Moreover, genetic screening is feasible in monkey PG-haESCs. Our results demonstrate that PGhaESCscan be generated from monkeys, providing an ideal tool for genetic analyses in primates².

References: 1. Yang H, et al. Generation of genetically modified mice by oocyte injection of androgenetic haploid embryonic stem cells. Cell 2012 149 (3) 605–617.

2. Yang H, et al. Generation of haploid embryonic stem cells from Macaca fascicularis monkey parthenotes. Cell Res 2013 23 1187–1200.