RESUMO
We investigated saccades, eyelid blinks, and their interaction in symptomatic (n = 22) and asymptomatic (n = 31) subjects with (n = 19) and without (n = 34) Parkin mutations. Saccadic hypometria was correlated with clinical symptoms of Parkinson's disease, irrespective of mutational status. By contrast, blink amplitude was increased in carriers of Parkin mutations independent of their clinical status. Saccade main sequence and blink effects on saccades were normal. We propose that increased blink amplitude may serve as an endophenotype in carriers of Parkin mutations.
Assuntos
Piscadela , Triagem de Portadores Genéticos/métodos , Mutação , Doença de Parkinson/genética , Movimentos Sacádicos , Ubiquitina-Proteína Ligases/genética , Adulto , Movimentos Oculares , Pálpebras , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/diagnóstico , FenótipoRESUMO
An efficient procedure for direct organogenesis and regeneration of hop (Humulus lupulus L.) was established. For the first time Agrobacterium-mediated genetic transformation of hop (cv. "Tettnanger") was achieved. Shoot internodes from in vitro cultures were identified as the most suitable type of explant for regeneration. Using this type of explant, a shoot-inducing medium was developed that supported direct organogenesis of approximately 50% of the explants. Plantlets were successfully rooted and transferred to the greenhouse. Overall, in less than 6 months hop cultures propagated in vitro were regenerated to plants in the greenhouse. Agrobacterium-mediated genetic transformation was performed with the reporter gene GUS (beta-glucuronidase). The presence and function of transgenes in plants growing in the greenhouse was verified by PCR (polymerase chain reaction) and enzyme assay for GUS activity, respectively. We have obtained 21 transgenic plants from 1,440 explants initially transformed, yielding an overall transformation efficiency of 1.5%.
Assuntos
Humulus/genética , Transformação Genética , Sequência de Bases , Quitinases/genética , Primers do DNA , Genótipo , Glucuronidase/genética , Humulus/microbiologia , Humulus/fisiologia , Canamicina/farmacologia , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase , RegeneraçãoRESUMO
Young pine seedlings respond to environmental stress by induced synthesis of pinosylvin, a stilbene phytoalexin. Heartwood of pine trees is characterized by a high content of pinosylvin. The formation of pinosylvin from cinnamoyl-CoA and three molecules malonyl-CoA catalysed by pinosylvin synthase is typical of the genus Pinus. Its enzyme activity not detectable in unstressed seedlings is substantially increased upon application of stimuli like UV-light or infection with the phytopathogenic fungus Botrytis cinerea. A genomic DNA library was screened with pinosylvin synthase cDNA pSP-54 as a probe. Ten clones were isolated and grouped into five subclasses according to the size of their introns. After subcloning into plasmid T7T3, four different members of the five gene subclasses were characterized by sequencing. Emphasis was put on isolating various promoters and analyzing and comparing their responsiveness. The amino acid sequences deduced from genes PST-1, PST-2, PST-3 and PST-5 shared an overall identity of more than 95%. In gene PST-5, the putative translation start site ATG was replaced by CTG. While promoter regions near the TATAA box were almost identical PST-1, PST-2 and PST-3, further upstream sequences differed substantially. Differences in promoter strength were analysed both in transgenic tobacco plants and by transient expression in tobacco protoplasts. Constructs used contained the bacterial beta-glucuronidase under the control of the promoters of pine genes PST-1, PST-2 and PST-3. Upon treatment with UV light or fungal elicitor, the promoter of PST-1 showed highest responsiveness and led to tissue-specific expression in vascular bundles. The data suggest that in pine the gene product of PST-1 is responsible for both the stress response in seedlings and pinosylvin formation in the heartwood.
Assuntos
Aciltransferases/genética , Família Multigênica , Árvores/enzimologia , Árvores/genética , Aciltransferases/metabolismo , Agrobacterium tumefaciens , Botrytis , Doenças das Plantas , Plantas Tóxicas , Regiões Promotoras Genéticas/efeitos da radiação , RNA Mensageiro/metabolismo , RNA de Plantas/metabolismo , Sementes/enzimologia , Sementes/genética , Sementes/microbiologia , Estilbenos/metabolismo , Nicotiana , Transfecção , Árvores/microbiologia , Raios UltravioletaRESUMO
Stilbene synthase cDNAs were isolated from a pine (Pinus sylvestris) cDNA library. Poly(A)+RNA required for the preparation was obtained from young seedlings challenged with Botrytis cinerea. A full-length cDNA encoding pinosylvin-forming stilbene synthase was sequenced, and the deduced amino acid sequence was compared with sequences of resveratrol-forming stilbene synthases. The cDNA coding for the key enzyme of pinosylvin formation is a valuable tool for detecting early effects of environmental stress in pine needles.
