Both the mouse cytosolic malate dehydrogenase gene and its mitochondrial counterpart contain eight introns, of which two are present at identical positions between the isozyme genes. The probability that the two intron positions coincide by chance between the two genes has been shown to be significantly small (=1.3×10−3), suggesting that the conservation of the intron positions has a biological significance. On the basis of a rooted phylogenetic tree inferred from a comparison of these isozymes and lactate dehydrogenases, we have shown that the origins of the conserved introns are very old, possibly going back to a date before the divergence of eubacteria, archaebacteria, and eukaryotes. In the aspartate aminotransferase isozyme genes, five of the introns are at identical places. The origins of the five conserved introns, however, are not obvious at present. It remains possible that some or all of the conserved introns have evolved after the divergence of eubacteria and eukaryotes.
Isozyme Intron Phylogenetic tree Evolution
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Fukasawa KM, Li SS (1987) Complete nucleotide sequence of the mouse lactate dehydrogenase-A functional gene: comparison of the exon-intron organization of dehydrogenase genes. Genetics 116:99–105PubMedGoogle Scholar
Iwabe N, Kuma K, Hasegawa M, Osawa S, Miyata T (1989) Evolutionary relationship of archaebacteria, eubacteria and eukaryotes inferred from phylogenetic trees of duplicated genes. Proc Natl Acad Sci USA 86:9355–9359PubMedGoogle Scholar
McAlister-Henn L (1988) Evolutionary relationships among the malate dehydrogenases. Trends Biochem Sci 13:178–181CrossRefPubMedGoogle Scholar
Obaru K, Tsuzuki T, Setoyama C, Shimada K (1988) Structural organization of the mouse aspartate aminotransferase isozyme genes: introns antedate the divergence of cytosolic and mitochondrial isozyme genes. J Mol Biol 200:13–22CrossRefPubMedGoogle Scholar
Quigley F, Martin WF, Cerff R (1988) Intron conservation across the prokaryote-eukaryote boundary: structure of the nuclear gene for chloroplast glyceraldehyde-3-phosphate dehydrogenase from maize. Proc Natl Acad Sci USA 85:2672–2676PubMedGoogle Scholar
Saitou N, Nei M (1987) The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 4:406–425PubMedGoogle Scholar
Setoyama C, Joh T, Tsuzuki T, Shimada K (1988) Structural organization of the mouse cytosolic malate dehydrogenase gene: comparison with that of the mouse mitochondrial malate dehydrogenase gene. J Mol Biol 202:355–364CrossRefPubMedGoogle Scholar
Takeshima H, Joh T, Tsuzuki T, Shimada K, Matsukado Y (1988) Structural organization of the mouse mitochondrial malate dehydrogenase gene. J Mol Biol 200:1–11CrossRefPubMedGoogle Scholar
Woese CR, Fox GE (1977) Phylogenetic structure of the prokaryotic domain: the primary kingdoms. Proc Natl Acad Sci USA 74:5088–5090PubMedGoogle Scholar