Genetic diversity in Rhizopus oryzae strains as revealed by the sequence of lactate dehydrogenase genes.
Twenty-seven strains of Rhizopus oryzae accumulating predominantly lactic acid were shown to possess two ldh genes, ldhA and ldhB, encoding NAD-dependent lactate dehydrogenases. Variation in nucleotide sequence was identified for each gene from different strains, and similar phylogenetic trees were obtained based on the nucleotide sequences of both genes. The other 21 strains of R. oryzae accumulating predominantly fumaric and malic acids contained a single ORF of ldhB. Compared to the strains accumulating predominantly lactic acid, a lower degree of sequence divergence was found in ldhB, resulting in a separate cluster in the phylogenetic tree. The high similarity (>90%) spanning the ORF and adjacent regions demonstrates that ldhA and ldhB are derived from the same ancestor gene. The strains accumulating predominantly fumaric and malic acids lack functional ldhA, which plays a role in lactic acid synthesis and may form a lineage separated from the strains accumulating predominantly lactic acid in the genus Rhizopus.
Department of Upland Agriculture, National Agricultural Research Center for Hokkaido Region, Memuro, Kasai, 082-0071, Hokkaido, Japan.
Katsuichi
K
Saito
Akane
A
Saito
Masao
M
Ohnishi
Yuji
Y
Oda
D004271:DNA, Fungal / Q000032:analysis; D005800:Genes, Fungal; D014644:Genetic Variation; D016681:Genome, Fungal; D007770:L-Lactate Dehydrogenase / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D019344:Lactic Acid / Q000096:biosynthesis*; D016366:Open Reading Frames; D010802:Phylogeny; D012233:Rhizopus / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development
D004271:DNA, Fungal; D019344:Lactic Acid; D007770:L-Lactate Dehydrogenase