Sterols in the trophosomes of the mermithid nematodes Neomesomermis flumenalis and Romanomermis culicivorax relative to sterols in the host hemolymph

The sterols in the trophosomes of Romanomermis culicivorax and Neomesomermis flumenalis were identified and compared with the sterols in the haemolymph of their larval insect hosts, Aedes aegypti and Simulium venustum, respectively. The C26 sterol 22-trans-24-norcholesta-5, 22-dien-3 beta -ol was predominant in the free sterol and sterol ester fractions of both nematodes. 22-dehydro-cholesterol was a major component of esterified and nonesterified sterols in the trophosomes of R. culicivorax and of free sterols in the trophosomes of N. flumenalis. Cholesterol was not a major trophosomal component in either of the nematodes. The host haemolymph contained cholesterol and beta -sitosterol as the principal free sterols in A. aegypti and as the only detectable free sterols in S. venustum. The evidence suggests that the mermithids have some capacity to interconvert sterols supplied by the hosts. [AS].RE: 32 ref.; SC: ZA; CA; PE; PA; VE; 0T; 0HSource type: Electronic(1