miR-335 is involved in the rat epididymal development by targeting the mRNA of RASA1

► The expression of miR-335 decreases from postnatal day 7 to 49 in the rat epididymis. ► The expression of RASA1 is inversely related to that of miR-335 during the rat epididymal development. ► miR-335 targets the mRNA of RASA1 and inhibits its expression, indicating that the downregulation of miR-335 at least in part causes the upregulation of RASA1 in the rat epididymis.