The nuclear genes of ciliates also have a non-standard genetic
code where two stop codons encode glutamine if I remember correctly.
There is a very recent paper by Baroin Tourancheau et al (1995)
EMBO J. 14 (13): 3262-3267 where the authors show that there were
multiple independent origins of this usage in ciliates.
Graham
___________________________
C. Graham Clark, Ph.D.
Laboratory of Parasitic Diseases,
National Institutes of Health,
Bethesda, MD 20892-0425, USA
Tel: 301-496-4740
FAX: 301-402-4941
e-mail: gclark at nih.gov
