Gender-specific gene expression in Brugia malayi

Brugia malayi is a mosquito-borne filarial nematode that causes lymphatic f ilariasis and elephantiasis in humans. The purpose of this study was to ide ntify and characterize genes that are expressed differentially in male and female B. malayi in hopes of gaining new insight into the reproductive biol ogy of the parasite. Two approaches were used. A 5' differential display PC R (splice leader differential display PCR, SL DD-PCR) was performed by PCR with splice leader and random primers on cDNA templates, and electronic sub traction was performed on expressed sequence tag (EST) cluster databases de veloped by the Filarial Genome Project (FGP). Gender-specific expression of candidate clones was confirmed by RT-PCR for six of 22 (27%) clones identi fied by DD and in seven of 15 (47%) clones identified by electronic subtrac tion. One clone was identified by both methods. Several female-specific clo nes had homology to known nematode genes that encode a fatty acid binding p rotein, a high mobility group protein, an eggshell protein, a glutamate-gat ed ion channel, and a collagen. However, most of the clones have no signifi cant homology to known genes or proteins in computer databases. This projec t has confirmed the value of SL DD-PCR and electronic subtraction for analy sis of gene expression in filariae. These two complimentary techniques may be generally applicable to the study of gender-specific (and by analogy sta ge specific) gene expression in other nematodes. (C) 1999 Elsevier Science B.V. All rights reserved.