Specific expression of Olpiwi1 and Olpiwi2 in medaka (Oryzias latipes) germ cells

► Two piwi homologues, Olpiwi1 and Olpiwi2, were identified in medaka. ► Olpiwi2 mRNA is produced from two chromosomes. ► Olpiwi1 is expressed specifically in adult and primordial germ cells. ► Olpiwi2 is expressed specifically in adult and primordial germ cells. ► Both Olpiwi1 and Olpiwi2 are maternal deposited into zygotes.