title: Mitochondrial DNA integrity changes with age but does not correlate with learning performance in honey bees.
abstract: The honey bee is a well-established model organism to study aging, learning and memory. Here, we used young and old forager honey bees to investigate whether age-related learning capacity correlates with mitochondrial function. The bees were selected for age and learning performance and mitochondrial function was evaluated by measuring mtDNA integrity, mtDNA copy number and mitochondrial gene expression. Quite unexpectedly, mtDNA from young bees showed more damage than mtDNA from older bees, but neither mtDNA integrity, nor mtDNA copy number nor mitochondrial gene expression correlated with learning performance. Although not statistically significant (p=0.07) the level of L-rRNA increased with age in good learners whereas it decreased in poor learners. Our results show that learning performance in honey bee does not correlate with absolute mitochondrial parameters like mtDNA damage, copy number or expression of mitochondrial genes, but may be associated with the ability to regulate mitochondrial activity.
authors.affiliation: Department of Medical Biochemistry, KDI, University of Oslo, Norway; Norwegian University of Life Sciences, Department of Chemistry, Biotechnology and Food Science, N-1432, Aas, Norway.
authors.forename: E M
authors.initials: EM
authors.lastname: Hystad
authors.affiliation: Norwegian University of Life Sciences, Department of Chemistry, Biotechnology and Food Science, N-1432, Aas, Norway; School of Life Sciences, Arizona State University, Tempe, AZ, USA.
authors.forename: G V
authors.initials: GV
authors.lastname: Amdam
authors.affiliation: Department of Medical Biochemistry, KDI, University of Oslo, Norway. Electronic address: lars.eide@medisin.uio.no.
authors.forename: L
authors.initials: L
authors.lastname: Eide
mesh_terms: D000375:Aging / Q000235:genetics* / Q000523:psychology; D000818:Animals; D001245:Association Learning / Q000502:physiology; D001516:Bees / Q000235:genetics* / Q000502:physiology; D004249:DNA Damage; D004272:DNA, Mitochondrial / Q000235:genetics*; D018628:Gene Dosage; D005786:Gene Expression Regulation / Q000502:physiology; D050259:Genes, Mitochondrial / Q000502:physiology; D020459:Genes, rRNA; D007858:Learning / Q000502:physiology*; D008297:Male; D023421:Models, Animal; D018384:Oxidative Stress / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial
keywords: Aging; DNA damage; Honey bee; Learning; mtDNA; rRNA