Transgenerational, ultrastructural analysis on the antioxidative effects of tocopherol on early gametogenesis in Caenorhabditis elegans grown in 100% oxygen.
The random, free-radical-mediated oxidations of biological molecules result in membrane degradation leading to cellular deterioration (B. Halliwell, Free Radical Res. Commun. 9, 1-32, 1990). External oxygen, prooxidants, and internally produced oxygen free radicals (oxyradicals), interact and alter the nature of biomembranes. Antioxidants, e.g., tocopherol (Vitamin E), inhibit such oxidative damage of free radicals. In the present study, the nematode Caenorhabditis elegans was grown under hyperoxia (100% oxygen) with or without the addition of Vitamin E to the growth media. The nematodes were viable under such conditions for at least eight generations, although fecundity gradually decreased through successive generations, presumably due to genetic load. Vitamin E was also shown to have a protective effect against paraquat, which is a strong, intracellular, oxidizing agent. Ultrastructural observations of early meiosis showed that the formation of synaptonemal complexes was compromised and that the telomeres failed to attach to the nuclear envelope. Those nematodes grown in 100% oxygen with 200 micrograms/ml Vitamin E had normal meiotic structures and normal fecundity. Thus, the presence of enhanced levels of intracellular Vitamin E resulted in protection against oxidative stress during gametogenesis.
Goldstein
P
P
Department of Biological Sciences, University of Texas at El Paso 79968.
Modric
T
T
D000818:Animals; D017173:Caenorhabditis elegans / Q000187:drug effects* / Q000235:genetics / Q000648:ultrastructure; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure; D002478:Cells, Cultured; D005298:Fertility / Q000187:drug effects / Q000235:genetics; D005718:Gametogenesis / Q000187:drug effects*; D007928:Lethal Dose 50; D010100:Oxygen / Q000037:antagonists & inhibitors* / Q000633:toxicity; D010269:Paraquat / Q000037:antagonists & inhibitors / Q000633:toxicity; D013574:Synaptosomes / Q000187:drug effects / Q000648:ultrastructure; D014810:Vitamin E / Q000494:pharmacology*
D014810:Vitamin E; D010269:Paraquat; D010100:Oxygen