New Biol 1989 Oct 01;11:93-100.

Shifting constraints on tRNA genes during mitochondrial DNA evolution in animals.

???displayArticle.abstract???
During the evolution of echinoderm mitochondrial (mt) DNA, a transfer RNA gene lost its tRNA function and became part of a protein-coding gene. To examine the evolutionary consequences of this event, we sequenced 961 bp of mtDNA in five sea urchin species. This enabled us to build a tree relating the mtDNAs and use it for analyzing the pattern and process of evolutionary substitutions in the former leucine tRNA gene, which now is a 5'' extension of the gene for NADH dehydrogenase subunit 5 (ND5). This 5'' extension is now evolving at the same rate and under the same protein-coding constraints as the rest of ND5. The adjacent (upstream) serine tRNA gene, however, has been evolving at a reduced rate, consistent with the possibility that it has assumed a punctuation role in processing of the primary transcript that was once fulfilled by the former leucine tRNA gene.

???displayArticle.pubmedLink??? 2488275



Genes referenced: cct5 LOC100887844 LOC105436960 LOC576114 LOC587800 mt-nd5