Cloning and Characterization of Voltage-Gated Calcium Channel Alpha1 Subunits in Xenopus laevis During Development

Voltage-gated calcium channels play a critical role in regulating the Ca2+ activity that mediates many aspects of neural development, including neural induction, neurotransmitter phenotype specification, and neurite outgrowth. Using Xenopus laevis embryos, we describe the spatial and temporal expression patterns during development of the 10 pore-forming alphal subunits that define the channels' kinetic properties. In situ hybridization indicates that Ca(V)1.2, Ca(V)2.1, Ca(V)2.2, and Ca(V)3.2 are expressed during neurula stages throughout the neural tube. These, along with Ca(V)1.3 and Ca(V)2.3, beginning at early tail bud stages, and Ca(V)3.1 at late tail bud stages, are detected in complex patterns within the brain and spinal cord through swimming tadpole stages. Additional expression of various alphal subunits was observed in the cranial ganglia, retina, olfactory epithelium, pineal gland, and heart. The unique expression patterns for the different alphal subunits suggests they are under precise spatial and temporal regulation and are serving specific functions during embryonic development. Developmental Dynamics 238:2891-2902, 2009. (C) 2009 Wiley-Liss, Inc.