The function of sperm-associated antigen 6 in neuronal proliferation and differentiation.

Sperm-associated antigen 6 (SPAG6) is initially found in human testis and is essential for sperm motility and male fertility. Later studies indicate that it also express in the chick Central Nervous System and human embryonic stem cells. However, the function of Spag6 in cortical development is still largely unclear. Using in utero electroporation, we showed that overexpression of Spag6 induced the transfected cells excluded from the proliferation zone of the mouse cortex. Ki67 Co-labeling and BrdU incorporation experiment suggested that overexpression of Spag6 inhibited proliferation of neural progenitor cells. Furthermore, we demonstrated that Spag6-overexpressing cells preferred to differentiated into neurons, which could be labeled by Brn2, rather than GFAP positive astrocytes. Taken together, our data indicate that Spag6 plays an essential role in the process of neuronal proliferation and differentiation.