Binds the poly(A) tail of mRNA. Unable to interact with the cap-binding complex and is therefore unlikely to be involved in translation initiation. Expressed both maternally and zygotically. Restricted to oogenesis and early embryogenesis. During oogenesis, levels increase between stage I and II and then remain constant through oocyte growth to stage VI. During early embryogenesis, levels remain approximately constant up to 5 days after fertilization. In older embryos levels decrease, being totally absent at 15 days post-fertilization (at protein level).