SPAG4--has been identified as nuclear envelope (NE) proteins. Using bioinformatic analysis indicated that SPAG4L contained a conserved SUN domain in the C-terminal. Subcellular localization analysis indicated that the expression of green fluorescent protein-labeled full-length SPAG4L was localized to the NE and the endoplasmic reticulum (ER). Spag4L express in meiosis I and II stages, possibly£¬suggesting that Spag4L is involved in NE reconstitution and nuclear migration occurring during the process of spermatocyte division.