KLC3 is involved in sperm tail midpiece formation and sperm function

► KLC3 is the only kinesin light chain known to be expressed in spermatids. ► High level expression of KLC3 in cell culture causes mitochondrial aggregate formation in a microtubule dependent manner. ► High level expression of a KLC3 mutant in transgenic mice can cause midpiece abnormalities. ► KLC3 mutant expressing transgenic mice are subfertile and produce sperm with impaired motility.