ISSN:
1432-1432
Keywords:
Mitochondrial DNA
;
Gene inversion
;
Nucleotide composition bias
;
Codon usage
;
Starfish
;
Sea urchin
;
Echinoderm
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The gene organization of starfish mitochondrial DNA is identical with that of the sea urchin counterpart except for a reported inversion of an approximately 4.6-kb segment containing two structural genes for NADH dehydrogenase subunits 1 and 2 (ND 1 and ND 2). When the codon usage of each structural gene in starfish, sea urchin, and vertebrate mitochondrial DNAs is examined, it is striking that codons ending in T and G are preferentially used more for heavy strand-encoded genes, including starfish ND 1 and ND 2, than for light strand-encoded genes, including sea urchin ND 1 and ND 2. On the contrary, codons ending in A and Care preferentially used for the light strand-encoded genes rather than for the heavy strand-encoded ones. Moreover, G-U base pairs are more frequently found in the possible secondary structures of heavy strandencoded tRNAs than in those of light strand-encoded tRNAs. These observations suggest the existence of a certain constraint operating on mitochondrial genomes from various animal phyla, which results in the accumulation of G and T on one strand, and A and C on the other.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02102653
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