Alterations in chromatin structure dynamically occur during germline development in Drosophila and are essential for the production of functional gametes. We had previously reported that the maternal factor Mamo, which contains both a BTB/POZ domain and C2H2 zinc-finger domains and is enriched in primordial germ cells (PGCs), is required for the regulation of meiotic chromatin structure and the production of functional gametes. However, the molecular mechanisms by which Mama regulates germline development remained unclear. To evaluate the molecular function of Mamo protein, we have investigated the binding of Mama to chromatin and DNA sequences. Our data show that Mama binds to chromatin and specific DNA sequences, particularly the polytene chromosomes of salivary gland cells. Overexpression of Mama affected the organization of polytene chromosomes. Reduction in maternal Mamo levels impaired the formation of germline-specific chromatin structures in PGCs. Furthermore, we found that the zinc-finger domains of Mamo directly bind to specific DNA sequences. Our results suggest that Mama plays a role in regulating chromatin structure in PGCs. (C) 2013 Elsevier Inc. All rights reserved.