title: Drosophila parkin mutants have decreased mass and cell size and increased sensitivity to oxygen radical stress.
abstract: Mutations in the gene parkin in humans (PARK2) are responsible for a large number of familial cases of autosomal-recessive Parkinson disease. We have isolated a Drosophila homolog of human PARK2 and characterized its expression and null phenotype. parkin null flies have 30% lower mass than wild-type controls which is in part accounted for by a reduced cell size and number. In addition, these flies are infertile, show significantly reduced longevity, and are unable to jump or fly. Rearing mutants on paraquat, which generates toxic free radicals in vivo, causes a further reduction in longevity. Furthermore, loss of parkin results in progressive degeneration of most indirect flight muscle (IFM) groups soon after eclosion, accompanied by apoptosis. However, parkin mutants have normal neuromuscular junction recordings during the third larval instar stage, suggesting that larval musculature is intact and that parkin is required only in pupal and adult muscle. parkin flies do not show an age-dependent dopaminergic neuron loss in the brain, even after aging adults for 3 weeks. Nevertheless, degeneration of IFMs demonstrates the importance of parkin in maintaining specific cell groups, perhaps those with a high-energy demand and the concomitant production of high levels of free radicals. parkin mutants will be a valuable model for future analysis of the mechanisms of cell and tissue degeneration.
authors.affiliation: Division of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Yakov
authors.initials: Y
authors.lastname: Pesah
authors.forename: Tuan
authors.initials: T
authors.lastname: Pham
authors.forename: Heather
authors.initials: H
authors.lastname: Burgess
authors.forename: Brooke
authors.initials: B
authors.lastname: Middlebrooks
authors.forename: Patrik
authors.initials: P
authors.lastname: Verstreken
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhou
authors.forename: Mark
authors.initials: M
authors.lastname: Harding
authors.forename: Hugo
authors.initials: H
authors.lastname: Bellen
authors.forename: Graeme
authors.initials: G
authors.lastname: Mardon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D048429:Cell Size; D003080:Cold Temperature; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000235:genetics / Q000502:physiology*; D006801:Humans; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D008969:Molecular Sequence Data; D009043:Motor Activity / Q000502:physiology; D009132:Muscles / Q000473:pathology / Q000502:physiology / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D018384:Oxidative Stress; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism*; D010300:Parkinson Disease / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D016415:Sequence Alignment; D012726:Sexual Behavior, Animal / Q000502:physiology; D044767:Ubiquitin-Protein Ligases; D014921:Wings, Animal / Q000166:cytology / Q000502:physiology
chemical_list: D029721:Drosophila Proteins; D017382:Reactive Oxygen Species; D044767:Ubiquitin-Protein Ligases; C487430:park protein, Drosophila; D010100:Oxygen