You are currently viewing the abstract.View Full Text
Scents and Sperm
Once sperm enter the female reproductive tract, they have an arduous task to find an egg at a distant, often concealed, location. McKnight et al. (p. 754) show that Caenorhabditis elegans make this task more or less difficult, depending on pheromones in the external environment. Pheromones perceived by female sensory neurons modulate the synthesis of ovarian prostaglandins, which provide sperm positional information. Thus, environmental cues can indirectly impact sperm function even when the sperm themselves are not directly exposed.
Environmental exposures affect gamete function and fertility, but the mechanisms are poorly understood. Here, we show that pheromones sensed by ciliated neurons in the Caenorhabditis elegans nose alter the lipid microenvironment within the oviduct, thereby affecting sperm motility. In favorable environments, pheromone-responsive sensory neurons secrete a transforming growth factor–β ligand called DAF-7, which acts as a neuroendocrine factor that stimulates prostaglandin-endoperoxide synthase [cyclooxygenase (Cox)]–independent prostaglandin synthesis in the ovary. Oocytes secrete F-class prostaglandins that guide sperm toward them. These prostaglandins are also synthesized in Cox knockout mice, raising the possibility that similar mechanisms exist in other animals. Our data indicate that environmental cues perceived by the female nervous system affect sperm function.