Trinucleotide repeat expansions are responsible for more than two dozens severe neurological disorders in humans. A double-strand break between two short CAG/CTG trinucleotide repeats was formerly shown to induce a high frequency of repeat contractions in yeast. Here, using a dedicated TALEN, we show that induction of a double-strand break into a CAG/CTG trinucleotide repeat in heterozygous yea...

BACKGROUND Amino acid sequence diversity is introduced into a phage-displayed peptide library by randomizing library oligonucleotide DNA. We recently evaluated the diversity of peptide libraries displayed on T7 lytic phage and M13 filamentous phage and showed that T7 phage can display a more diverse amino acid sequence repertoire due to differing processes of viral morphogenesis. METHODS In t...

The placement of the extreme thermophile Aquifex aeolicus in the bacterial phylogenetic tree has evoked much controversy. We investigated whether adaptations for growth at high temperatures would alter a key functional component of the replication machinery, specifically DnaG primase. Although the structure of bacterial primases is conserved, the trinucleotide initiation specificity for A. aeol...

Tandem repeats, that is simple sequence repeats, occur commonly in the human genome, and they have long been used as markers in linkage studies. In this decade, it has also been found that tandem repeats underlie an entirely new class of human mutations. The expansion of a group of trinucleotide repeats is now known to cause several inherited diseases, all of which are neurological disorders. T...

Major insights have been attained into the molecular pathology of the trinucleotide repeat neurodegenerative diseases over the past decade. Genetic definition has allowed subclassification into translated polyglutamine diseases, which are due to CAG repeat expansions, and a more heterogeneous group in which the trinucleotide repeat remains untranslated. The polyglutamine disorders are due to a ...

Background Androgen receptor (AR) mediates androgen actions such as initiation and promotion of spermatogenesis and growth of accessory sex organs. There are two trinucleotide polymorphisms (CAG and GGN repeats) in exon1 of AR gene that are vary in length in population. The CAG and GGN repeats association with infertility is still unknown and this study is planned to assess the distribution of ...

Trinucleotide repeat expansions are the genetic cause of numerous human diseases, including fragile X mental retardation, Huntington disease, and myotonic dystrophy type 1. Disease severity and age of onset are critically linked to expansion size. Previous mouse models of repeat instability have not recreated large intergenerational expansions ("big jumps"), observed when the repeat is transmit...

Lengthy trinucleotide repeats encoding polyglutamine (polyQ) stretches characterize the variant proteins of Huntington's disease and certain other inherited neurological disorders. Using a phenotypic screen to identify events that restore functionality to polyQ proteins in S. cerevisiae, we discovered that transcription elongation factor Spt4 is required to transcribe long trinucleotide repeats...

Expansion of (AGC)n repeats has been associated with genetic disorders called triplet-repeat diseases such as Huntington's disease (HD), myotonic muscular dystrophy (DM) and Kennedy's disease. To gain insight into the abnormal behavior of these repeats, we studied their structural properties in supercoiled DNA. Chemical probing revealed that, under physiological salt and pH conditions, Zn2+ or ...