Blepharophimosis-ptosis-epicanthus inversus syndrome type I is an autosomal disorder caused by mutations in FOXL2 gene and associated with premature ovarian failure in women by a dominant inheritance. FOXL2 is a recently identified protein that belongs to forkhead family transcription factor, of which signaling pathways are still unknown. Here, we show that FOXL2 induces apoptosis in both Chinese hamster ovary cells and rat granulosa cells, and it interacts with DP103, a DEAD box-containing protein. Overexpression of DP103 itself did not affect cell viability while its coexpression with FOXL2 led to the potentiation of cell death. Our results present previously undiscovered functions of these proteins, an apoptotic activity of FOXL2 in the ovary and a modulating activity of DP103 by interacting with FOXL2. (c) 2005 Elsevier Inc. All rights reserved.