Ascidians, such asCiona, are invertebrate chordates with simple embryonic body plans and small, relatively non-redundant genomes.Cionagenetics is in its infancy compared to many other model systems, but it provides a powerful method for studying this important vertebrate outgroup. Here we give basic methods for genetic analysis ofCiona, including protocols for controlled crosses both by natural spawning and by the surgical isolation of gametes; the identification and propagation of mutant lines; and strategies for positional cloning.
