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Veitinger S.,RWTH Aachen | Veitinger S.,Ruhr University Bochum | Veitinger T.,RWTH Aachen | Cainarca S.,Axxam SpA | And 9 more authors.
Journal of Physiology | Year: 2011

Intimate bidirectional communication between Sertoli cells and developing germ cells ensures the integrity and efficiency of spermatogenesis. Yet, a conceptual mechanistic understanding of the physiological principles that underlie Sertoli cell autocrine and paracrine signalling is lacking. Here, we characterize a purinergic Ca 2+ signalling network in immature mouse Sertoli cells that consists of both P2X2 and P2Y2 purinoceptor subtypes, the endoplasmic reticulum and, notably, mitochondria. By combining a transgenic mouse model with a dedicated bioluminescence imaging device, we describe a novel method to monitor mitochondrial Ca 2+ mobilization in Sertoli cells at subcellular spatial and millisecond temporal resolution. Our data identify mitochondria as essential components of the Sertoli cell signalling 'toolkit' that control the shape of purinergic Ca 2+ responses, and probably several other paracrine Ca 2+-dependent signals. © 2011 The Authors. Journal compilation © 2011 The Physiological Society.

Veitinger T.,RWTH Aachen | Veitinger T.,Ruhr University Bochum | Riffell J.R.,University of Arizona | Veitinger S.,RWTH Aachen | And 13 more authors.
Journal of Biological Chemistry | Year: 2011

In the female reproductive tract, mammalian sperm undergo a regulated sequence of prefusion changes that "prime" sperm for fertilization. Among the least understood of these complex processes are the molecular mechanisms that underlie sperm guidance by environmental chemical cues. A "hard-wired" Ca2+ signaling strategy that orchestrates specific motility patterns according to given functional requirements is an emerging concept for regulation of sperm swimming behavior. The molecular players involved, the spatiotemporal characteristics of such motility-associated Ca2+ dynamics, and the relation between a distinct Ca2+ signaling pattern and a behavioral sperm phenotype, however, remain largely unclear. Here, we report the functional characterization of two human sperm chemoreceptors. Using complementary molecular, physiological, and behavioral approaches, we comparatively describe sperm Ca2+ responses to specific agonists of these novel receptors and bourgeonal, a known sperm chemoattractant. We further show that individual receptor activation induces specific Ca2+ signaling patterns with unique spatiotemporal dynamics. These distinct Ca2+ dynamics are correlated to a set of stimulus-specific stereotyped behavioral responses that could play vital roles during various stages of prefusion sperm-egg chemical communication. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc.

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