Insect Juvenile Hormone Signaling May Shed Light On Mechanisms Of Longevity And Obesity
Carey Williams, Desiree Mills, Jamie Bozeman, Jerbrea Powell, Ta’Kiya Moore and Scoty Hearst
Department of Biology, Tougaloo College, Tougaloo MS
Today, human aging and obesity are areas of considerable health concern and the primary focus of much biomedical research. Many scientists suggest that insects may help decipher the mechanisms of aging and obesity. Here, we examine a juvenile hormone analog and its impact on the darkling beetle tenebtio molitor. Darkling beetles or commonly known as mealworms, are often used in many branches of biological research. The darkling beetle life stages include egg, larva, pupa, and adult. Juvenile hormone analogues, such as methoprene, acts like hormones present during the juvenile stage of certain insect’s development and are commonly used alongside insecticides. Methoprene does not serve to kill insects that it affects, it only acts as a hormone controlling insect growth. Based on previous studies, it has been observed that methoprene interferes with the metamorphosis of insects, such as darkling beetles, by preventing the insect’s exit of the larva stage. Previous research has indicated that methoprene also modulates insect insulin-signaling pathways in drosophila. In this study, we assessed the effect of methoprene treatment on the developmental life stages of the darkling beetle tenebtio molitor. We hypothesized that methoprene treatment would slow the progression of metamorphosis through the beetle life cycle. Interestingly, we found that methoprene treatment inhibits adult development, keeping the insects in the larval mealworm stage indefinitely. Furthermore, methoprene increased insect longevity as compared to untreated control groups. Methoprene treatment significantly increased darkling beetle larval lifespan as compared to untreated groups. Also, methoprene treatment resulted in larger and heavier darkling beetle larva as compared to untreated groups. Our preliminary data suggest that juvenile hormone signaling pathways may be important modulators of longevity, body size, and obesity. Our future studies are to determine how methoprene impacts insulin-signaling pathways in darkling beetles and to determine how those pathways contribute to longevity, increased body size and obesity, which may be translatable to humans. This work was supported by the Mississippi INBRE, funded by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103476. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of General Medical Sciences or the National Institutes of Health.