Jansen Vera, Alvarez Luis, Balbach Melanie, Strünker Timo, Hegemann Peter, Kaupp U Benjamin, Wachten Dagmar
Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany.
Institute of Biology, Experimental Biophysics, Humboldt University of Berlin, Berlin, Germany.
Elife. 2015 Jan 20;4:e05161. doi: 10.7554/eLife.05161.
Optogenetics is a powerful technique to control cellular activity by light. The light-gated Channelrhodopsin has been widely used to study and manipulate neuronal activity in vivo, whereas optogenetic control of second messengers in vivo has not been examined in depth. In this study, we present a transgenic mouse model expressing a photoactivated adenylyl cyclase (bPAC) in sperm. In transgenic sperm, bPAC mimics the action of the endogenous soluble adenylyl cyclase (SACY) that is required for motility and fertilization: light-stimulation rapidly elevates cAMP, accelerates the flagellar beat, and, thereby, changes swimming behavior of sperm. Furthermore, bPAC replaces endogenous adenylyl cyclase activity. In mutant sperm lacking the bicarbonate-stimulated SACY activity, bPAC restored motility after light-stimulation and, thereby, enabled sperm to fertilize oocytes in vitro. We show that optogenetic control of cAMP in vivo allows to non-invasively study cAMP signaling, to control behaviors of single cells, and to restore a fundamental biological process such as fertilization.
光遗传学是一种通过光来控制细胞活动的强大技术。光门控通道视紫红质已被广泛用于研究和操纵体内神经元活动，而体内第二信使的光遗传学控制尚未得到深入研究。在本研究中，我们展示了一种在精子中表达光激活腺苷酸环化酶（bPAC）的转基因小鼠模型。在转基因精子中，bPAC模拟了运动和受精所需的内源性可溶性腺苷酸环化酶（SACY）的作用：光刺激迅速升高cAMP，加速鞭毛摆动，从而改变精子的游动行为。此外，bPAC替代了内源性腺苷酸环化酶活性。在缺乏碳酸氢盐刺激的SACY活性的突变精子中，bPAC在光刺激后恢复了运动能力，从而使精子能够在体外使卵母细胞受精。我们表明，体内cAMP的光遗传学控制允许非侵入性地研究cAMP信号传导，控制单细胞行为，并恢复诸如受精等基本生物学过程。
