Cyclic Nucleotide-Specific Optogenetics Highlights Compartmentalization of the Sperm Flagellum into cAMP Microdomains.
                            
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                                bPAC (BlaC)
                            
                                LAPD
                            
                            
                                
                                    HEK293
                                
                            
                                
                                    mouse sperm cells
                                
                            
                            
                                Signaling cascade control
                            
                                Control of cytoskeleton / cell motility / cell shape
                            
                                Immediate control of second messengers
                            
                            
                            
                            
                            
                        
                        
                        
                        
                            Abstract:
                            Inside the female genital tract, mammalian sperm undergo a maturation process called capacitation, which primes the sperm to navigate across the oviduct and fertilize the egg. Sperm capacitation and motility are controlled by 3',5'-cyclic adenosine monophosphate (cAMP). Here, we show that optogenetics, the control of cellular signaling by genetically encoded light-activated proteins, allows to manipulate cAMP dynamics in sperm flagella and, thereby, sperm capacitation and motility by light. To this end, we used sperm that express the light-activated phosphodiesterase LAPD or the photo-activated adenylate cyclase bPAC. The control of cAMP by LAPD or bPAC combined with pharmacological interventions provides spatiotemporal precision and allows to probe the physiological function of cAMP compartmentalization in mammalian sperm.