What are alternatives to Xenopus eggs? - (Nov/19/2012 )

I am reading this article about nuclear membrane and pores. They use the cellular content of Xenopus frog eggs to study chromatin binding.

http://jcb.rupress.org/content/189/7/1129.long

my question is, why don't they just use culture cells instead of growing frog eggs? I mean, it is difficult to take care of frogs and breed them to produce eggs. After all their concern is eukaryotic nucleporins. just why not use cells in the flask?

Eggs = big, and literally covered with membrane transporters, cultured cells = small and generally not so densly covered with transporters.

It actually isn't difficult to care for and produce eggs from Xenopus, and you can get a LOT of eggs from one frog.

thanks bob1, as always.