Search results for "Strand"

Gene Repair of an Usher Syndrome Causing Mutation by Zinc-Finger Nuclease Mediated Homologous Recombination

2012

PURPOSE. Human Usher syndrome (USH) is the most frequent cause of inherited deaf-blindness. It is clinically and genetically heterogeneous, assigned to three clinical types of which the most severe type is USH1. No effective treatment for the ophthalmic component of USH exists. Gene augmentation is an attractive strategy for hereditary retinal diseases. However, several USH genes, like USH1C, are expressed in various isoforms, hampering gene augmentation. As an alternative treatment strategy, we applied the zinc-finger nuclease (ZFN) technology for targeted gene repair of an USH1C, causing mutation by homologous recombination. METHODS. We designed ZFNs customized for the p.R31X nonsense mut…

Yeast dsRNA viruses: replication and killer phenotypes

1991

The cytoplasmic L-A dsRNA virus of Saccharomyces cerevisiae consists of a 4.5 kb dsRNA and the two gene products it encodes; the capsid (cap) and at least one copy of the capsid-polymerase (cap-pol) fusion protein. Virion cap-pol catalyses transcription of the plus (sense)-strand; this is extruded from the virus and serves as messenger for synthesis of cap and cap-pol. Nascent cap-pol binds to a specific domain in the plus strand to initiate encapsidation and then catalyses minus-strand synthesis to complete the replication cycle. Products of at least three host genes are required for replication, and virus copy number is kept at tolerable levels by the SKI antivirus system. S. cerevisiae k…

High Diversity of the Viral Community from an Antarctic Lake

2009

Viruses are the most abundant biological entities and can control microbial communities, but their identity in terrestrial and freshwater Antarctic ecosystems is unknown. The genetic structure of an Antarctic lake viral community revealed unexpected genetic richness distributed across the highest number of viral families that have been found to date in aquatic viral metagenomes. In contrast to other known aquatic viromes, which are dominated by bacteriophage sequences, this Antarctic virus assemblage had a large proportion of sequences related to eukaryotic viruses, including phycodnaviruses and single-stranded DNA (ssDNA) viruses not previously identified in aquatic environments. We also o…

Mutations in the β-tropomyosin (TPM2) gene – a rare cause of nemaline myopathy

2002

Nemaline myopathy is a clinically and genetically heterogeneous muscle disorder. In the nebulin gene we have detected a number of autosomal recessive mutations. Both autosomal dominant and recessive mutations have been detected in the genes for alpha -actin and alpha -tropomyosin 3. A recessive mutation causing nemaline myopathy among the Old Order Amish has recently been identified in the gene for slow skeletal muscle troponin T. As linkage studies had shown that at least one further gene exists for nemaline myopathy, we investigated another tropomyosin gene expressed in skeletal muscle, the beta -tropomyosin 2 gene. Screening 66 unrelated patients, using single strand conformation polymor…

Screening for multiple hereditary hypercoagulability factors using the amplification refractory mutation system

2003

Many hereditary factors have been implicated in the development of arterial and/or venous thromboembolic diseases. A number of these risk factors can be identified by the amplification refractory mutation system (ARMS). However, the underlying technical conditions for performing ARMS are highly variable, and depend on which risk factors are being analyzed. We have now developed a novel ARMS-based system to simultaneously screen for multiple hypercoagulability factors under identical PCR conditions. This can greatly simplify the process of screening for hereditary hypercoagulability.

Two distinct amplification events of the c-myc locus in a colorectal tumour.

2008

Southern hybridisation of genomic DNA extracted from a human primary colorectal carcinoma revealed amplification of a fragment containing the wild-type c-myc locus. Two additional rearranged DNA fragments, lying upstream of c-myc, fused to distant non-contiguous sequences from the same chromosome, with an opposite configuration (head to head vs. head to tail), were also found to be amplified. Sequences analysis suggested that these rearrangements resulted from illegitimate recombination at two distinct points within the DNA sequence just upstream of the c-myc ORF and further that these events triggered two different amplification mechanisms, only one of which, involving a strand invasion ev…

Complement component C3: molecular basis of the C3*S025 variant and evidence for molecular heterogeneity of other variants.

1995

Complement component 3 (C3) is the central molecule of the complement system. It displays a number of polymorphic variants with, as yet, unclear functional consequences. We have investigated a number of rare C3 variants by PCR-SSCP (polymerase chain reaction-single strand conformation polymorphism) analysis and could identify the molecular basis of a C3*S025 variant. The decreased electrophoretic mobility of this protein is caused by the exchange of a neutral serine residue to an arginine residue (positively charged). This exchange is unlikely to have functional consequences as it maps to the C-terminus of the alpha-chain. C3 variants appear to have originated from various independent mutat…

Dejerine-Sottas neuropathy associated with De Novo S79P mutation of the peripheral myelin protein 22 (PMP22) gene

1998

Laser Pressure Catapulting (LPC): Optimization LPC-System and Genotyping of Colorectal Carcinomas

2005

Genotype analysis is becoming more and more useful in clinical practice, since specific mutations in tumors often correlate with prognosis and/or therapeutic response. Unfortunately, current molecular analytical techniques often require time-consuming and costly steps of analysis, thus making their routine clinical use difficult. Moreover, one of the most difficult problems arising during tumor research is that of their cell heterogeneity, which depends on their clear molecular heterogeneity. SSCP analysis discriminates by means of aberrant electrophoresis migration bands, mutated alleles which may represent as little as 15-20% of their total number. Nevertheless, in order to identify by se…

Molecular markers for systematic identification and population genetics of the invasive Ponto-Caspian freshwater gammarid Dikerogammarus villosus (Cr…

2006

The Ponto-Caspian amphipod, Dikerogammarus villosus, is an invasive species of many European rivers. First, we show that size difference of nrDNA ITS1 allows discriminating D. villosus from Dikerogammarus bispinosus, a closely related but morphologically hardly distinguishable species. Second, we present two types of polymorphic markers for D. villosus, three microsatellites and two single nucleotide polymorphisms (SNPs) of mtDNA COI gene, which were scored by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP). These markers will be very useful in studying population genetics of D. villosus.