title: Clonorchis sinensis: codon usage in nuclear genes.
abstract: Codon usage in Clonorchis sinensis was analyzed using 12,515 codons from 38 coding sequences. Total GC content was 49.83%, and GC1, GC2 and GC3 contents were 56.32%, 43.15% and 50.00%, respectively. The effective number of codons converged at 51-53 codons. When plotted against total GC content or GC3, codon usage was distributed in relation to GC3 biases. Relative synonymous codon usage for each codon revealed a single major trend, which was highly correlated with GC content at the third position when codons began with A or U at the first two positions. In codons beginning with G or C base at the first two positions, the G or C base rarely occurred at the third position. These results suggest that codon usage is shaped by a bias towards G or C at the third base, and that this is affected by the first and second bases.
authors.affiliation: Department of Parasitology, Chung-Ang University College of Medicine, Tongjak-gu, Seoul 156-756, Republic of Korea.
authors.forename: Yi
authors.initials: Y
authors.lastname: Tang
authors.forename: Pyo Yun
authors.initials: PY
authors.lastname: Cho
authors.forename: Tae Im
authors.initials: TI
authors.lastname: Kim
authors.forename: Sung-Jong
authors.initials: SJ
authors.lastname: Hong
mesh_terms: D000596:Amino Acids / Q000235:genetics; D000818:Animals; D001482:Base Composition / Q000502:physiology; D002467:Cell Nucleus / Q000235:genetics; D003004:Clonorchis sinensis / Q000737:chemistry / Q000235:genetics*; D003062:Codon / Q000737:chemistry / Q000502:physiology*
chemical_list: D000596:Amino Acids; D003062:Codon