Unique age-related transcriptional signature in the nervous system of the long-lived red sea urchin Mesocentrotus franciscanus

The red sea urchin, Mesocentrotus franciscanus, is one the earth's longest-lived animals, reported to live more than 100 years with indeterminate growth, life-long reproduction and no increase in mortality rate with age. To gain insight into mechanisms associated with longevity and negligible senescence, age-related transcriptional profiles were examined in tissues of the red sea urchin. Genome-wide transcriptional profiling using RNA-Seq revealed few age-related changes in gene expression in muscle and esophagus tissue. In contrast, radial nerve showed an unexpected level of complexity with the expression of 3,370 genes significantly altered more than two-fold with age, including genes involved in nerve function, signaling, metabolism, transcriptional regulation and chromatin modification. There was an age-related upregulation in expression of genes involved in synaptogenesis, axonogenesis and neuroprotection suggesting preservation of neuronal processes with age. There was also an upregulation in expression of positive regulators and key components of the AMPK pathway, autophagy, proteasome function, and the unfolded protein response. This unique age-related gene expression profile in the red sea urchin nervous system may play a role in mitigating the detrimental effects of aging in this long-lived animal.