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The Adventures of Lion Man™ and Eaglewoman™

Go into any comic shop and you will see a plethora of human-animal hybrid heroes and heroines: Batman, Spiderman, Catwoman, et al.

Out in the real world, fusing human and animal characteristics took a major knock this week.

Stem cell scientists have long sought ways to create patient-specific cells with the potency and growth characteristics of embryonic stem cells. One method (in theory at least) to achieve that would be to introduce the nucleus from a patient’s cell into an enucleated human egg. These hybrid cells could be used to develop large numbers of whatever cell type the patient needs replaced.

Due to a boatload of ethical and practical issues, gaining access to a supply of human eggs for this purpose is almost impossible, so scientists have turned to non-human species as egg donors.

With the possible exception of science fiction devotees, many people react to the prospect of human-animal hybrids with squeamishness or frank outrage. It’s a challenge to find anyone who has a rosy feeling about human-bovine hybrids, even if they are a stepping-stone to cures for serious diseases (as their promoters assert).

Well worry no more! Robert Lanza and colleagues have recently proven what many intuitively know: that human nuclei and non-human eggs just don’t get along. The problem appears to be a lack of communication between the animal egg and human donor nucleus. The lack of crosstalk leads to down-regulation of the genes needed for pluripotency and blocks development.

As a scientist myself, I know that one thing we excel at is unleashing mysterious forces we cannot control. Luckily this one didn’t make it out of the starting gate.