Search results for "Amy"
showing 10 items of 1486 documents
Structural and functional characterization of a transcription-enhancing sequence element in the rbcL gene of the Chlamydomonas chloroplast genome.
2002
The structure and function of a transcription-enhancing sequence element in the coding region of the Chlamydomonas reinhardtii rbcL gene was analyzed in Chlamydomonas chloroplast transformants in vivo. The enhancer sequence is contained within a DNA segment extending from position +108 to position +143, relative to the start site of rbcL gene transcription. The sequence remains functional when inverted or when placed 34 bp closer to or 87 bp further downstream of the basic rbcL promoter. However, it does not function from a site about 250 bp downstream of its original location. Besides promoting transcription initiation from the rbcL promoter, the element is able to augment transcription fr…
Specific roles of 5′ RNA secondary structures in stabilizing transcripts in chloroplasts
2005
RNA secondary structures, e.g. stem-loops that are often found at the 5' and 3' ends of mRNAs, are in many cases known to be crucial for transcript stability but their role in prolonging the lifetime of transcripts remains elusive. In this study we show for an essential RNA-stabilizing stem-loop at the 5' end of rbcL gene transcripts in Chlamydomonas that it neither prevents ribonucleases from binding to the RNA nor impedes their movement along the RNA strand. The stem-loop has a formative function in that it mediates folding of a short sequence around its base into a specific RNA conformation, consisting of a helical and single-stranded region, i.e. the real structure required for longevit…
Mutational analysis of eggplant latent viroid RNA processing in Chlamydomonas reinhardtii chloroplast.
2009
Viroids of the family Avsunviroidae, such as eggplant latent viroid (ELVd), contain hammerhead ribozymes and replicate in the chloroplasts of the host plant through an RNA-based symmetrical rolling-circle mechanism in which oligomeric RNAs of both polarity are processed to monomeric linear RNAs (by cleavage) and to monomeric circular RNAs (by ligation). Using an experimental system consisting of transplastomic lines of the alga Chlamydomonas reinhardtii, a mutational analysis of sequence and structural elements in the ELVd molecule that are involved in transcript processing in vivo in a chloroplastic context was carried out. A collection of six insertion and three deletion ELVd mutants was …
Self-diploidization in Saccharomyces cerevisiae kar2 heterokaryons
1993
Zygotes isolated by micromanipulation from crosses of Saccharomyces cerevisiae strains, one of which carries a kar mutation, give rise most frequently to cytoductant colonies showing the nuclear constitution of either one of the two haploid parental strains. In crosses of kar2-1 strains to wild-type, about 10% of the cytoductants of both mating types are homozygous autodiploids. There is evidence indicating that self-diploidization occurs by fusion between sibling nuclei in the heterokaryotic zygote. Here we describe this phenomenon and propose to take advantage of it for the construction of genotypically-defined diploids able to mate, and of polyploid strains, which are useful tools in gen…
Characterization of R-plasmids in environmental isolates ofsalmonella: Host range and stability
1988
Four environmental isolates ofSalmonella, resistant to several drugs, were examined for plasmid carriage with four different plasmid DNA isolation procedures. The method of Birnboim and Doly gave the best results. Three of the strains possessed a single plasmid with molecular weights of 60 (kanamycin resistant), 44.5 (kanamcin resistant), and 23.4 Md (ampicillin and amoxicillin resistant); the other strain (resistant to tetracycline) harbored two plasmids of 69.8 and 2.2 Md. The 69.8 Md was the one responsible for resistance. All plasmids were fi−, and the 44.5 Md Kcr plasmid synthesized a sex pilus type F. Some properties related to the dissemination of R-plasmids, such as host range, tran…
Genome-Based Examination of Chlorophyll and Carotenoid Biosynthesis in Chlamydomonas reinhardtii
2005
Abstract The unicellular green alga Chlamydomonas reinhardtii is a particularly important model organism for the study of photosynthesis since this alga can grow heterotrophically, and mutants in photosynthesis are therefore conditional rather than lethal. The recently developed tools for genomic analyses of this organism have allowed us to identify most of the genes required for chlorophyll and carotenoid biosynthesis and to examine their phylogenetic relationships with homologous genes from vascular plants, other algae, and cyanobacteria. Comparative genome analyses revealed some intriguing features associated with pigment biosynthesis in C. reinhardtii; in some cases, there are additiona…
Indication of a common origin of German and American Families with Familial Amyloidneuropathy Typ II
1999
Abstract The classification of familial amyloid neuropathies (FAP) is traditionally based on clinical and regional aspects. In the last 10 years more than 40 mutations of the transthyretin gene have been found to be responsible for different clinical forms of amyloidosis including familial FAP.FAP II is caused by a mutation on the codon 58 of the transthyretin gene. Only two american kindreds (the Maryland/German and the Ohio family) have previously been reported with FAP II starting in the 3rd or 4th decade by sensory disturbances of the hands typically as a carpal tunnel syndrome. We report on a german family with FAP II from the rhine river area south of Mainz. Four members with typical …
INDIVIDUAL AND HEALTH-RELATED QUALITY OF LIFE ASSESSMENT IN AMYOTROPHIC LATERAL SCLEROSIS PATIENTS AND THEIR CAREGIVERS
2004
Abstract: We performed a cross-sectional study aimed to address the quality of life (QoL) and putative associated variables in amyotrophic lateral sclerosis (ALS) patients and their respective caregivers, using both health-related (WHOQOL-BREF) and individual (SEIQoL-DW) QoL instruments. Further, we sought to investigate concordance within patient-caregiver pairs for ratings of respective QoL. Thirty-seven patient-caregiver pairs were included in the study. QoL was rated low by both patients and caregivers, and there was no significant difference between them on scores of overall QoL, even if caregivers showed higher scores on the physical and psychological WHOQOL-BREF domains compared to p…
Physical exercise in the prevention and treatment of Alzheimer's disease
2020
Highlights • Low levels of physical activity are a risk factor associated with Alzheimer's disease. • Older adults who exercise are more likely to maintain cognition. • Exercise modulates amyloid β turnover, inflammation, synthesis, and release of neurotrophins, and cerebral blood flow.
Effects of Different Chair-Based Exercises on Salivary Biomarkers and Functional Autonomy in Institutionalized Older Women
2019
The aim of this study was to test the effects of chair-based exercise programs on salivary stress hormones, physical fitness, and functional autonomy of institutionalized older women.In total, 47 participants (80 ± 8.04 years old) were recruited and allocated into three groups: chair-based aerobic exercises (CAE, n = 19), chair-based elastic-band strength exercises (CSE, n = 15), and a control group (CG, n = 13). A 14-week exercise intervention was done for the CAE and CSE groups, two times per week, in no consecutive days. Members of the CG did not participate in any type of exercise but kept their regular lifestyle. Fear of falling, autonomy, physical fitness, salivary cortisol, and alpha…