Submitted to: Invertebrate Survival Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/11/2012
Publication Date: 6/15/2012
Citation: Stanley, D.W. 2012. Aging and immunosenescence in invertebrates. Invertebrate Survival Journal. 9:102-109.
Interpretive Summary: The concept of biological control of insects is based on the idea that direct application of some pathogens and parasites can reduce pest insect populations and the economic damage due to pest insects. The problem, however, is the efficiency of these organisms in biological control programs is limited by insect immune defense reactions to challenge. Similarly, limited understanding of the age-related decline in immune functions in insects and other invertebrates is a barrier to optimizing biocontrol programs for insects and optimizing aquaculture conditions for farmed invertebrate food animals. In this paper I inject a new concept into thinking about age-related declines in immune functions by suggesting that understanding of these declining immune functions can be applied to improving biological control programs and to sustaining invertebrate food resources. This new idea will be directly useful to scientists who are working to improve the efficacy of biological control methods and those working on sustainability of invertebrate food resources. These enhancements will benefit agricultural producers and the global population who consume their products.
Technical Abstract: Most contemporary research into aging is driven by interest in the human aging process and in interventions that attenuate the normal and pathophysiological effects of aging, or senescence. Operationally, senescence is the progressive, inevitable breakdown of the organism. Among the changes associated with senescence is the diminished capacity of the immune systems and reactions to challenge, known as immunosenescence. Senescence and age-related immunosenescence has been recorded in several invertebrates, including insects. Two invertebrates, the worm, Caenorhabditis elegans, and the fruit fly, Drosophila melanogaster, are model organisms for research into mechanisms of senescence and of prolonged life spans. In this essay, I will treat some of the available information on immunosenescence in invertebrates. The purpose is to move away from trying to understand human senescence and toward generating new ideas around the application of research into invertebrate immunosenescence to contemporary and emerging problems in aquatic and terrestrial agriculture. I cover mechanisms of senescence, beginning with the original idea of increasing oxidative damage and moving to more recent views. I provide a thumb-nail sketch of insect immunity as a model for the generality of complex invertebrates, then discuss selected examples of immunosenescence in invertebrates. In some instances, changes that look like immunosenescence may be physiological resource trade-offs and I highlight a few examples. Finally, I complete the essay with a few remarks on the potential practical significance of research to understand immunosenescence in invertebrates.