Table 2.

Estimated genome characteristics

	Kudoa	Polypodium	Hydra (39)	Nematostella (38)
Genome size (Mb)	22.5	561	1,005	450
No. protein genes	5,533	17,440	16,839	18,000
GC content, %	28	47	29	41
Mean intron size, bp	82	1,163	2,673	799
Mean exon size, bp	102	216	218	208