ABSTRACT
The ancestral gene appears to have arisen in a group o f bacteria, and possibly was inherited by eukaryotes as a result o f genome fusion (see Chapter 4). Given this hypothetical beginning, lipocalins are expected to be found in all descendants of the eukaryotic common ancestor. Currendy, and aside of prokaryotes, bona fide lipocalins have been recovered from a protoctist, a fungus, several plants, a nematode, several arthropods, a tunicate, a cephalochordate, and many examples o f chordates.
