1. Population samples of Bactrocera albistrigata from Peninsular Malaysia were analyzed for 12 to 14 gene-enzyme systems comprising 15-18 loci. 2. Three loci, aMDH, PGD and PGM, were polymorphic. 3. Anodal malate dehydrogenase and phosphogluconate dehydrogenase were represented by two alleles each, while phosphoglucomutase was represented by three alleles. 4. Phosphoglucomutase had a higher heterozygosity than anodal malate dehydrogenase and phosphogluconate dehydrogenase. 5. B. albistrigata was characterized by low genetic variability, as measured by the proportion of polymorphic loci and heterozygosity.
A biochemical genetic study of the enzyme malate dehydrogenase (MDH) was conducted in the grasshopper Oxya j. japonica. Analysis of MDH electrophoretic variation in this species of grasshopper shows that one of the two autosomal loci for MDH in grasshoppers, the Mdh-2 locus, controlling the anodal set of MDH isozymes, is duplicated. Results of breeding studies confirm this and the observed polymorphism at the Mdh-2 locus in the two populations of Oxya j. japonica studied can be attributed to three forms of linked alleles at the duplicated locus in equilibrium in both populations. In this respect, all individuals of this species possess heterozygous allelic combinations at the duplicated Mdh-2 locus, which may account for the spread of the duplicated locus in the populations of this species of grasshopper.
Mitochondrial malic enzyme (EC 1.1.1.40; MEM) was examined by starch-gel electrophoresis on post-mortem brain samples from 453 unrelated subjects of either sex comprising 161 Chinese, 150 Indians and 113 Malays and 29 from other racial groups. The estimated gene frequencies of MEM1 were found to be 0.7111, 0.6100 and 0.6769 in Chinese, Indians and Malays, respectively. No significant deviation from the Hardy-Weinberg equilibrium was observed in Chinese and Malays. However, there was a significant deviation with a deficiency of heterozygotes among Indians. MES did not show any polymorphism.
Programmed cell death (PCD) is a genetically regulated process of cell suicide essential for plant development. The 'malate valve' is a mechanism that ensures redox balance across different subcellular compartments. In broccoli, the BomMDH1 gene encodes malate dehydrogenase in mitochondria, a critical enzyme in the 'malate circulation' pathway. This study investigates the functional role of BomMDH1 in malate (MA)-induced apoptosis in bright yellow-2 (BY-2) suspension cells. Findings revealed that transgenic cells overexpressing BomMDH1 showed enhanced viability under MA-induced oxidative stress compared to wild-type (WT) cells. Overexpression of BomMDH1 also reduced levels of reactive oxygen species (ROS), hydrogen peroxide (H2O2), and malondialdehyde (MDA), while increasing the expression of antioxidant enzyme genes such as NtAPX, NtAOX1a, NtSOD, and NtMDHAR. Additionally, treatment with salicylhydroxamic acid (SHAM), a characteristic inhibitor of mitochondrial respiration, further improved the anti-apoptotic activity of BY-2 cells. Overall, these results highlighted the function of the BomMDH1 gene and the potential of SHAM treatment in mitigating oxidative stress in BY-2 suspension cells.