title: Localization, structure and polymorphism of two paralogous Xenopus laevis mitochondrial malate dehydrogenase genes.
abstract: Two paralogous mitochondrial malate dehydrogenase 2 (Mdh2) genes of Xenopus laevis have been cloned and sequenced, revealing 95% identity. Fluorescence in-situ hybridization (FISH) combined with tyramide amplification discriminates both genes; Mdh2a was localized into chromosome q3 and Mdh2b into chromosome q8. One kb cDNA probes detect both genes with 85% accuracy. The remaining signals were on the paralogous counterpart. Introns interrupt coding sequences at the same nucleotide as defined for mouse. Restriction polymorphism has been detected in the first intron of Mdh2a, while the individual variability in intron 6 of Mdh2b gene is represented by an insertion of incomplete retrotransposon L1Xl. Rates of nucleotide substitutions indicate that both genes are under similar evolutionary constraints. X. laevis Mdh2 genes can be used as markers for physical mapping and linkage analysis.
authors.affiliation: Department of Animal Physiology and Developmental Biology, Faculty of Science, Charles University in Prague, Vinicna 7, Prague 2, 128 43, Czech Republic. ttlapka@natur.cuni.cz
authors.forename: Tereza
authors.initials: T
authors.lastname: Tlapakova
authors.forename: Vladimir
authors.initials: V
authors.lastname: Krylov
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Macha
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002875:Chromosomes; D003001:Cloning, Molecular; D017124:Conserved Sequence; D020224:Expressed Sequence Tags; D020131:Genes, Duplicate; D014644:Genetic Variation; D017404:In Situ Hybridization, Fluorescence; D007438:Introns; D007621:Karyotyping; D008291:Malate Dehydrogenase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques; D011110:Polymorphism, Genetic; D018626:Retroelements; D017386:Sequence Homology, Amino Acid; D014982:Xenopus laevis / Q000235:genetics*
chemical_list: D018626:Retroelements; D008291:Malate Dehydrogenase