Evolution. In the article “The role of robustness and changeability on the origin and evolution of genetic codes” by Tetsuya Maeshiro and Masayuki Kumura, which appeared in number 9, April 28, 1998, of Proc. Natl. Acad. Sci. USA (95, 5088–5093), the authors wish to note the following error in Table 2 related to the initiation codons of nuclear mycoplasma. They should read: AUG, GUG, and UUG [Dybvig, K. & Voelker, L. L. (1996) Annu. Rev. Microbiol. 50, 25–57]. Consequently, CMy (page 5091, last paragraph, right column) should be deleted in the text. These corrections do not change the results of the paper. A corrected Table 2 is shown below.

Table 2.

Assignments of deviant codons

Representative genetic system	Code	Changes from SGC		Initiation codons
		Codon	Phenotype
Mitochondrial yeasts	MYe	UGA	stop  ⇒ Trp	AUG	1
		AUA	Ile  ⇒ Met
		CUN	Leu  ⇒ Thr
Mitochondrial platyhelminths	MPl	UGA	stop  ⇒ Trp	AUG	1
		AAA	Lys  ⇒ Asn
		AGR	Arg  ⇒ Ser
		UAA	stop  ⇒ Tyr
Mitochondrialnematoda	MNe	UGA	stop  ⇒ Trp	AUN UUG GUG	6
arthropoda		AGR	Arg  ⇒ Ser
mollusca		AUA	Ile  ⇒ Met
Mitochondrial echinodermata	MEc	UGA	stop  ⇒ Trp	AUG	1
		AAA	Lys  ⇒ Asn
		AGR	Arg  ⇒ Ser
Mitochondrial tunicata	MTu	UGA	stop  ⇒ Trp	AUG	1
		AUA	Ile  ⇒ Met
		AGR	Arg  ⇒ Gly
Mitochondrial vertebrata	MVe	UGA	stop  ⇒ Trp	AUN GUG	5
		AUA	Ile  ⇒ Met
		AGR	Arg  ⇒ stop
Mitochondrial euascomycetes	MEu	UGA	stop  ⇒ Trp	AUN NUG UUA	8
Nuclear mycoplasma	CMy	UGA	stop  ⇒ Trp	AUG GUG UUG	3
Nuclear euplotes	CEu	UGA	stop  ⇒ Cys	AUG	1
Nuclear acetabularia	CAc	UAR	stop  ⇒ Gln	AUG	1
Nuclear blepharisma	CBl	UAG	stop  ⇒ Gln	AUG	1
Nuclear candida	CCa	CUG	Leu  ⇒ Ser	AUG CUG	2
Nuclear bacterial	CBa	—	—	AUN NUG	7

N denotes any of A, U, G, and C, and R denotes A and G. The values in the initiation codons indicate the number of known initiation codons. The codon reassignments of each deviant code are arranged from top to bottom in the estimated order of reassignments. Compiled from http://www3.ncbi.nlm.nih.gov/htbin-post/Taxonomy/wprintgc?mode=c.