Researchers at Cornell reported the ability to generate new pluripotent stem cell lines from embryos which began not as a union of sperm and egg, but rather of an egg and an embryonic stem cell. The investigators found that the stem cells placed in the ooplasm of the egg underwent haploidization (lost half of their chromosomes) and acted as the male germ cell. The embryos that developed from that process were then used to develop a 2nd generation stem cell line.

A team of scientists from the University of Pennsylvania also used mouse embryonic stem cells, this time to explore their ability to differentiate into egg-like cells. The investigators used a set of specially colored proteins to help them assess if the cell had taken on egg-like qualities. Based upon the expression of several key genes found in oocytes, the team concluded that mouse embryonic stem cells were capable of being cultured in a laboratory to develop into gametes.

?This is the kind of exciting work that shows the huge potential of embryonic stem cells. We look forward to the next advances from these outstanding scientists,? said Robert Schenken, MD, President of the ASRM.

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