Endocrine disruption in the context of life cycles: perception and transduction of environmental cues

Environmental and social stresses have major impacts on the life cycles of organisms. Furthermore, habitat disturbance/destruction, global climate change, and existence of endocrine disrupting chemicals (EDCs) due to human activities are increasingly likely to pose additive and synergistic stresses that could have potential deleterious effects on physiological function in vertebrates. Central to an organism's life cycle is the ability to respond to environmental cues, physical and social. Environmental signals may act directly on endocrine tissues, but most act through neural pathways, and neuroendocrine and endocrine secretions that affect changes in morphology, physiology and behavior. While most investigations focus on endocrine secretions and their effects, we know much less about perception and transduction of environmental signals. Additionally, some populations of vertebrates, from fish to mammals, temporarily resist environmental and social stresses, and breed successfully. However, many show varying degrees of failure, sometimes resulting in marked population decline. There is potential for EDCs to act at all levels of the response systems to environmental cues. Because animals live in diverse habitats, there is variation in susceptibility to disruption of response systems to environmental cues. Although this may be partly due to genetic differences at a level of receptors and/or metabolism, fundamental differences in how species perceive environmental cues and respond to them may also be major factors. Here we discuss how EDCs may interact with the perception and transduction of environmental cues that are important for all organisms in their natural world. This may introduce a new perspective on the effects of environmental endocrine disruptors.