Gene evolution

[J. Carvajal]

Hi all:

I do have a general question.

Does anyone know of an example where two genes that are separated in, lets
say C. elegans or S. cerevisiae, come together in mammalian evolution?  

In other words, is any mammalian gene known to be composed by to unrelated
genes in a lower organism?

Thanks in advance,

J. Carvajal