A malic enzyme probe detects cross-hybridizing sequences closely linked to loci encoding other metabolic enzymes.
The cytoplasmic malic enzyme (Mod-1) catalyzes the oxidative decarboxylation of malate: malate + NADP+----pyruvate + CO2 + NADPH + H+. Using a cDNA clone of Mod-1 as a probe, two new DNA markers not at the Mod-1 locus (restriction fragment length polymorphisms, RFLP) were detected by Southern blot analysis that showed extensive homology to Mod-1 sequences. Linkage of each restriction fragment length polymorphism to loci other than Mod-1 was assessed using the BXD (C57BL/6J x DBA/2J) recombinant inbred strains and confirmed by backcrosses. One polymorphic site, designated D9Rti1, was found to be closely linked to the phosphoglucomutase (Pgm-3) locus on Chromosome 9. The other hybridization site, designated D1Rti2, was closely linked to the isocitrate dehydrogenase (Idh-1) locus on Chromosome 1. The data presented imply that Mod-1 homologous sequences are tightly linked to three different metabolic enzymes.
Cobb
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RR
Chemistry and Life Sciences Group, Research Triangle Institute, Research Triangle Park, North Carolina 27709.
Rinchik
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E
Barnett
L B
LB
Burkhart
J G
JG
Lewis
S E
SE
D000818:Animals; D003433:Crosses, Genetic; D015342:DNA Probes; D008040:Genetic Linkage; D005819:Genetic Markers; D007521:Isocitrate Dehydrogenase / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009693:Nucleic Acid Hybridization; D010733:Phosphoglucomutase / Q000378:metabolism; D012150:Polymorphism, Restriction Fragment Length
D015342:DNA Probes; D005819:Genetic Markers; D008291:Malate Dehydrogenase; D007521:Isocitrate Dehydrogenase; D010733:Phosphoglucomutase