Egg-derived tyrosine phosphatase as a Potential Biomarker for Muscle Ageing and Degeneration in Drosophila melanogaster

Ageing is associated with declined activity of behaviors, physiology and metabolic processes (Arking, 2006). Investigations in model organisms have indicated the existence of “functional senescence”, the progressive decline of biological functions with age and the decline in the activity may vary from tissue to tissue. Consequently, studies pertaining to the key organs/tissues whose functions deteriorate/fail with age have led to the development of tissue specific ageing biomarkers (Grotewiel et al., 2005 and Demontis et al., 2013). Muscle constitutes the bulk of body mass in majority of eukaryotes. Besides its contractile function, studies from model organisms have indicated muscles to play a prominent role in ageing. Major age-related changes that are apparent in muscle include alteration in gene expression pattern, accumulation of poly-ubiquitin protein aggregates, a decline in protein synthesis, increased mitochondrial and nuclear DNA damage and eventually progressive increase in apoptosis. Genetic interventions through signaling events not only showed a delay in age-related muscle deterioration but also increased stress resistance and metabolic homeostasis, which led to extended lifespan (Demontis and Perrimon, 2010). Dietary restriction also plays a role in modulating lifespan by fine tuning the muscle activities. So, there are overwhelming evidences to suggest that muscle does play significant roles during ageing (Demontis and Perrimon, 2010 and Demontis et al., 2013). Unraveling the interconnections between muscle and ageing is imperative considering the massive increase of age-related problems including sarcopenia (Sayer et al., 2013). The identification of biomarkers based on different disease conditions would greatly help in clinically assessing the etiology for accurate prognosis and treatment. Skeletal muscle specific molecular signatures that could be used as biomarkers for identification of sarcopenia and muscle ageing have been reported (Holland and Ohlendieck, 2013). However, the detailed mechanisms involved are not well understood. For such studies, accessibility of a suitable model system is indispensable.