Ldha Knockout mouse models

Ldha encodes the mouse ortholog of human LDHA, the M subunit of lactate dehydrogenase, which assembles into homotetramers and hybrid tetramers with LDHB and preferentially reduces pyruvate to lactate while regenerating cytosolic NAD+, sustaining glycolysis when oxidative capacity or oxygen delivery is limiting. Transcription is driven by HIF1A and MYC, making the gene a canonical Warburg effector, and human LDHA deficiency causes glycogen storage disease type XI with exertional myoglobinuria and a blunted rise in blood lactate during ischemic exercise testing. Allele options map to distinct questions: a conditional null with Ckmm-Cre or a tumor-restricted Cre tests glycolytic dependence and lactate export, patient missense knockins reproduce partial deficiency and exercise-triggered rhabdomyolysis, and humanization supports LDHA inhibitor pharmacology. Because Ldhb is co-expressed and forms hybrid tetramers retaining activity, isoform-resolved zymography is required before attributing changes to LDHA. Match allele to endpoint, whether lactate flux and NAD+ to NADH ratio, tumor growth, or ischemic exercise physiology.

Whole body loss of Ldha gives the clearest readout when the question is whether the gene is required at all. Follow up tissue work can still move to a conditional allele if lethality or compensation appears.