title: Transcript profiles of long- and short-lived adults implicate protein synthesis in evolved differences in ageing in the nematode Strongyloides ratti.
abstract: The nematode Strongyloides ratti shows remarkable phenotypic plasticity in ageing, with parasitic adults living at least 80-times longer than free-living adults. Given that long- and short-lived adults are genetically identical, this plasticity is likely to be due to differences in gene expression. To try and understand how this inter-morph difference in longevity evolved, we compared gene expression in long- and short-lived adults. DNA microarray analysis of long- and short-lived adults identified 32 genes that were up-regulated in long-lived adults, and 96 genes up-regulated in short-lived adults. Strikingly, 38.5% of the genes expressed more in the short-lived morph are predicted to encode ribosomal proteins, compared with only 9% in the long-lived morph. Among the 32 longevity-associated genes there was very little enrichment of genes linked to cellular maintenance. Overall, we have therefore observed a negative correlation between expression of ribosomal protein genes and longevity in S. ratti. Interestingly, engineered reduction of expression of ribosomal protein genes increases lifespan in the free-living nematode Caenorhabditis elegans. Our study therefore suggests that differences in levels of protein synthesis could contribute to evolved differences in animal longevity.
authors.affiliation: School of Biological Sciences, University of Bristol, Woodland Road, Bristol, BS8 1UG, UK.
authors.forename: Fiona J
authors.initials: FJ
authors.lastname: Thompson
authors.forename: Gary L A
authors.initials: GL
authors.lastname: Barker
authors.forename: Tony
authors.initials: T
authors.lastname: Nolan
authors.forename: David
authors.initials: D
authors.lastname: Gems
authors.forename: Mark E
authors.initials: ME
authors.lastname: Viney
mesh_terms: D000375:Aging / Q000235:genetics; D000818:Animals; D019143:Evolution, Molecular; D020869:Gene Expression Profiling / Q000379:methods; D005838:Genotype; D015801:Helminth Proteins / Q000096:biosynthesis / Q000235:genetics*; D008136:Longevity / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D014176:Protein Biosynthesis / Q000235:genetics*; D012269:Ribosomal Proteins / Q000235:genetics*; D017170:Strongyloides ratti / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D015801:Helminth Proteins; D012269:Ribosomal Proteins