|Baek, Hwang Soon|
Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 5/12/2005
Publication Date: 10/1/2005
Citation: Lee, E., Baek, H., Lee, J., Chitwood, D.J., Paik, Y. 2005. Elevated cholesterol level in a caenorhabditis elegans line is correlated with increased longevity and stress resistance. Journal of Nematology. 37:379. Interpretive Summary:
Technical Abstract: Like all nematodes, Caenorhabditis elegans possesses a nutritional requirement for sterol because of lack of several enzymes in the de novo sterol biosynthesis pathway. Similar to most plant-parasitic nematodes, C. elegans converts plant sterols to cholesterol. Unlike phytoparasitic nematodes, C. elegans introduces an additional double bond at carbon 7 to form 7-dehydrocholesterol. In animals that biosynthesize cholesterol de novo, the enzyme 7-dehydrocholesterol reductase (DHCR) catalyzes the reverse of this reaction, i.e., the reduction of 7-dehydrocholesterol to cholesterol. Analysis of sterols from C. elegans fed 7-dehydrocholesterol indicates that the DHCR-catalyzed reaction does not occur in C. elegans. In order to determine the effects of alterations in sterol composition on C. elegans, a mammalian DHCR expression vector was injected and then chromosomally incorporated. The transgenic C. elegans contained 80% more cholesterol than wild-type nematodes. The transgenic strain produced 40% fewer offspring than the wild type; the mean life span of the transgenic strain was 31% longer in sterol-deficient medium than the wild type. Survival of the transgenic C. elegans was longer than that of the wild type after exposure to ultraviolet irradiation or temperature stress (35 degrees C).