Sperm mitochondrial sheath formation — how and why?

Abstract

The sperm tail is a modified motile cilium analogous to those found in tissues including the lung and brain. They have been evolutionarily sculpted to optimize motility and, therefore, fertility, through the dynamic and challenging environment of the female reproductive tract. Sperm tails are composed of three structurally distinct regions: the midpiece, the principal piece and the end piece. The most proximal region — the midpiece — is surrounded by a mitochondrial sheath, which has been proposed to provide structural integrity and ATP as fuel for sperm tail movement. Despite the main phases of mitochondrial sheath assembly being described, the specific biological mechanisms that underpin i..