This had been impossible in the past because, unlike mammalian egg cells which are tiny and transclucent, a bird's egg cell is filled with opaque yolk and it is huge — this means that finding the nucleus is like looking for a white marble in a pool of milk. (reviverestore.org)
He believes it's possible that a similar enzyme functions in mammalian eggs, but he says that further work will be necessary to confirm this. (sciencemag.org)
«Animal experiments led to the conclusion that mammalian eggs do not have polarity, but I think that's a huge fallacy,» said David Albertini, a developmental biologist at Tufts University in Boston. (discovermagazine.com)