Three levels of regulation lead to protamine and Mst77F expression in Drosophila

► Regulation of expression of sperm chromatin components at multiple levels. ► Testis specific TAF Sa binds to the protamine B gene. ► The open reading frame is required for strict translational repression of protamine B and Mst77F mRNA. ► Spermatocytes contain the transregulatory mechanisms to hinder Protamine B and Mst77F protein accumulation. ► Late spermatids contain the machinery to allow Protamine B and Mst77F protein accumulation.