Figure 7
A model for the regulation of mitochondrial dynamics in spermiogenesis. (a) During normal spermiogenesis, Pld6 (MitoPLD) generates PA from CL. Gykl1 is expressed in round spermatids. Gykl1 and Gk2 physically interact with Pld6 and facilitate Pld6-mediated PA biogenesis, which further induces mitochondrial fusion. Mitochondrial PA is then converted into LysoPA by Pa-pla1, which induces mitochondrial fission. PA, LysoPA and other signaling lipids together regulate mitochondrial dynamics and contribute to mitochondrial sheath formation during spermiogenesis. (b) In spermatids lacking Gykl1 or Gk2, PA, LPA and other lipids that regulate mitochondria dynamics are reduced, which contributes to disordered mitochondrial morphology, abnormal regulation of mitochondrial dynamics and disrupted midpiece formation.
