title: Protein synthesis rates in Drosophila associate with levels of the hsr-omega nuclear transcript.
abstract: Transcripts of the Drosophila hsr-omega gene are known to interact with RNA processing factors and ribosomes and are postulated to aid in co-ordinating nuclear and cytoplasmic activities particularly in stressed cells. However, the significance of these interactions for physiological processes and in turn for whole-organism fitness remains an open question. Because hsr-omega's cellular expression characteristics suggest it may influence protein synthesis, and because both genotypic and expression variation of hsr-omega have been associated with thermotolerance, we characterised 30 lines for variation in the rates of protein synthesis, measured in ovarian tissues, both before and after a mild heat shock, and for basal levels of the two main hsr-omega transcripts, omega-n and omega-c. As expected, the mild heat shock reduced protein synthesis rates. Large variation occurred among lines in levels of omega-n which was negatively associated with rates of basal protein synthesis--a result that supports the model for the cellular function of omega-n. Furthermore, omega-n levels were associated with hsr-omega genotype of the line parents. Little variation occurred among lines for omega-c levels and no associations were detected with protein synthesis or genotype. Since protein synthesis is a fundamental process for growth and development, we characterised the lines for several life-history traits; however, no associations with protein synthesis, omega-n or omega-c levels were detected. Our results are consistent with the idea that natural variation in hsr-omega expression influence rates of protein synthesis in this species.
authors.affiliation: Centre for Environmental Stress and Adaptation Research (CESAR), School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia.
authors.forename: Travis K
authors.initials: TK
authors.lastname: Johnson
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Carrington
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Hallas
authors.forename: Stephen W
authors.initials: SW
authors.lastname: McKechnie
mesh_terms: D000483:Alleles; D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D014644:Genetic Variation; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D018869:Heat-Shock Response / Q000502:physiology; D008297:Male; D010053:Ovary / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D014158:Transcription, Genetic
chemical_list: D029721:Drosophila Proteins; D006360:Heat-Shock Proteins