Brugia malayi: Localization of nitric oxide synthase in a lymphatic filariid

Nitric oxide synthase converts L-arginine to citrulline and nitric oxide, a gaseous signaling molecule critical to multiple physiological responses. N itric oxide synthase was detected by Western blot analysis of Brugia malayi extracts using an antibody raised against a peptide from murine brain nitr ic oxide synthase. Using NADPH diaphorase staining and immunohistochemistry , nitric oxide synthase was localized in the parasitic nematode B. malayi. As in Ascaris suum, nitric oxide synthase was detected in the body wall mus cles of adult B. malayi. This localization pattern is in agreement with the role of nitric oxide in the control of muscle tone in other invertebrates and in vertebrates. A novel finding was the localization of nitric oxide sy nthase in the oocytes, in developing embryos, and in spermatozoa. B. malayi nitric oxide synthase may play a role in developmental signaling, as has b een suggested for Drosophila and Ilyanassa, a marine mud snail. (C) 2000 Ac ademic Press.