• Bacteria: The code is used in
Entomoplasmatales and
Mycoplasmatales (Bove
et al. 1989). The situation in the
Acholeplasmatales is unclear. Based on a study of ribosomal protein genes, it had been concluded that UGA does not code for tryptophan in plant-pathogenic
mycoplasma-like organisms (MLO) and the
Acholeplasmataceae (Lim and Sears, 1992) and there seems to be only a single
tRNA-CCA for tryptophan in
Acholeplasma laidlawii (Tanaka
et al. 1989). In contrast, in a study of codon usage in
Phytoplasmas, it was found that 30 out of 78
open reading frames analysed translated better with this code (UGA for tryptophan) than with
the bacterial, archaeal and plant plastid code while the remainder showed no differences between the two codes (Melamed
et al. 2003). In addition, the coding reassignment of UGA Stop → Trp can be found in an alpha-proteobacterial
symbiont of
cicadas:
Candidatus Hodgkinia cicadicola (McCutcheon
et al. 2009).
Mycoplasma pneumoniae also uses the
codon UGA to code for
tryptophan rather than using it as a stop codon. • Fungi:
Emericella nidulans,
Neurospora crassa,
Podospora anserina,
Acremonium (Fox, 1987),
Candida parapsilosis (Guelin
et al., 1991),
Trichophyton rubrum (de Bievre and Dujon, 1992),
Dekkera/Brettanomyces,
Eeniella (Hoeben
et al., 1993), and probably
Ascobolus immersus,
Aspergillus amstelodami,
Claviceps purpureaand
Cochliobolus heterostrophus. • Protists: the
red algae of
Gigartinales (Boyen
et al. 1994), the protozoa
Trypanosoma brucei,
Leishmania tarentolae,
Paramecium tetraurelia,
Tetrahymena pyriformis and probably
Plasmodium gallinaceum (Aldritt
et al., 1989), and the
stramenopile Cafileria marina. • Metazoa:
Coelenterata (
Ctenophora and
Cnidaria). • Other: this code is also used for the
kinetoplast DNA (
maxicircles,
minicircles). Kinetoplasts are modified
mitochondria (or their parts). ==See also==