Generation of Medaka Fish Haploid Embryonic Stem Cells
Meisheng Yi,
Ni Hong,
Yunhan Hong*
Haploid embryonic stem (ES) cells combine haploidy and pluripotency,
enabling direct genetic analyses of recessive phenotypes in
vertebrate cells. Haploid cells have been elusive for culture,
due to their inferior growth and genomic instability. Here,
we generated gynogenetic medaka embryos and obtained three haploid
ES cell lines that retained pluripotency and competitive growth.
Upon nuclear transfer into unfertilized oocytes, the haploid
ES cells, even after genetic engineering, generated viable offspring
capable of germline transmission. Hence, haploid medaka ES cells
stably maintain normal growth, pluripotency, and genomic integrity.
Mosaic oocytes created by combining a mitotic nucleus and a
meiotic nucleus can generate fertile fish offspring. Haploid
ES cells may offer a yeast-like system for analyzing recessive
phenotypes in numerous cell lineages of vertebrates in vitro.
* To whom correspondence should be addressed. E-mail: dbshyh{at}nus.edu.sg
