Three isoforms of Brugia malayi daf-16 activate a reporter gene in cultured HepG2 cells

We hypothesize that infective stage molting in the parasitic nematode <i>Brugia malayi</i> is regulated by an ortholog of the <i>Caenorhabditis elegansdaf-16</i> gene, similar to the role of <i>daf-16</i> in dauer formation and recovery. We confirmed the gene structure of three isoforms of <i>B. malayi daf-16 (Bma-daf-16)</i> and generated cell culture expression constructs for each. In luciferase assays using transfected HepG2 cells, all three isoforms activated a luciferase reporter gene regulated by six DAF-16 binding sites, although <i>Bma-</i> DAF-16a showed lower activation ability than <i>Bma-</i> DAF-16b and <i>Bma-</i> DAF-16c. These results support our hypothesis that <i>Bma-daf-16</i> functions similarly to <i>C. elegansdaf-16</i> .