BACKGROUND & OBJECTIVES Echovirus 11 (ECV11) is one of the most frequent non-polio enteroviruses isolated from stool samples of children with acute flaccid paralysis in north India. The present work was undertaken to study the sequence variability in the 440 bp of 5'-non-translated region of ECV11 genome using heteroduplex mobility assay (HMA). METHODS Twelve ECV11 isolates were studied for s...

Several advanced techniques to detect mutations have been developed during the last years. Scanning procedures can be classified as "physical" and "cleavage" methodologies. Physical methods include Denaturing Gradient Gel Electrophoresis, Single-Strand Conformation Polymorphism and Heteroduplex Analysis while cleavage methods include RNAse A Cleavage, Chemical Mismatch Cleavage and Enzyme Misma...

The yeast Saccharomyces cerevisiae encodes a set of genes that show strong amino acid sequence similarity to MutS and MutL, proteins required for mismatch repair in Escherichia coli. We examined the role of MSH2 and PMS1, yeast homologs of mutS and mutL, respectively, in the repair of base pair mismatches formed during meiotic recombination. By using specifically marked HIS4 and ARG4 alleles, w...

The recA protein of Escherichia coli promotes the complete exchange of strands between full-length linear duplex and single-stranded circular phi X174 DNA molecules. Analysis of the reaction by electron microscopy confirms that D loops containing short heteroduplex regions are rapidly formed at the ends of the linear duplex, followed by a relatively slow branch migration that converts the D loo...

Deafness is a partial or total hearing loss that can appear at any ages and with different degrees of severity. About 50% of hearing disorders have a genetic origin, and among them, the nonsyndromic sensorineural deafness represents 70% of the cases. Out of these, the 80% correspond to autosomal recessive inheritance deafness. Autosomal recessive deafness has not been characterized enough at mo...

BACKGROUND Denaturing HPLC (DHPLC) is a semi-automated method for detecting unknown DNA sequence variants. The sensitivity of the method is dependent on the temperature at which the analysis is undertaken, the selection of which is dependent on operator experience. To circumvent this, software has been developed for predicting the optimal temperature for DHPLC analysis. We examined the utility ...

A series of overlapping recombinant clones, which cover the vitellogenin gene, has been isolated from a phage-lambda linked chicken gene library. The DNA of the overlapping clones spans 28 kb of contiguous DNA sequences in the chicken genome. Electron microscopic analysis of hybrids between vitellogenin mRNA and the genomic clones indicates that the chicken vitellogenin gene has a length of app...

A polymerase chain reaction (PCR) heteroduplex assay (HDA) was developed to identify avian derived mosquito blood meals to the species level. The assay used primers amplifying a fragment of the cytochrome B gene from vertebrate but not invertebrate species. In Culex tarsalis fed on quail, PCR products derived from the quail cytochrome B gene were detected seven days post-engorgement. In an anal...

Heteroduplex analysis of the RNA isolated from purified virions of clone 3 Moloney murine sarcoma virus (M-MSV) hybridized to cDNA's from Moloney murine leukemia virus (M-MLV) and clone 124 M-MSV shows that the main physical component of clone 3 RNA is missing all or most of the 1.5-kilobase (kb) clone 124 M-MSV specific sequence denoted beta s (S. Hu et al. Cell 10:469--477, 1977). This sequen...

S1 nuclease (EC 3.1.4.X), a single-strand-specific nuclease, can be used to accurately map the location of mutational alterations in simian virus 40 (SV40) DNA. Deletions of between 32 and 190 base pairs, which are at or below the limit of detectability by conventional electron microscopic analysis of heteroduplex DNAs, have been located in this way. To map a deletion, a mixture of unit length,...