background: germline mutations in mmr genes are reported to be present in more than 70% of hnpcc cases. but, there is a paucity of data regarding the importance of defect of mmr system in the gastric cancer in general. so, in this study, we used ihc stain formlh1,msh2, pms2 andmsh6 to reveal profile ofmmr expression in patients with gastric cancer. materials and methods: this study was performe...

background: meiotic genes are very important candidates for genes contributing to female and male infertility. mammalian mutl homologues have dual roles in dna mismatch repair (mmr) after replication errors and meiotic reciprocal recombination. the mutl homologs, mlh1 and mlh3 , are crucial for meiotic reciprocal recombination and human fertility. in this study the functional polymorphisms of m...

background: hereditary non-polyposis colorectal cancer (hnpcc) is a common hereditary cancer predisposing syndrome has molecular and clinicopathological features still have remained ambiguous within iranian populations. we discuss in this article some molecular and clinicopathological features of the condition. methods: the study was a descriptive retrospective and designed on 1659 colorectal c...

The process of mismatch repair was first postulated to explain the results of experiments on genetic recombination and bacterial mutagenesis. Mismatch repair has long been known to play a major role in two cellular processes: (1) the repair of errors made during DNA replication or as the result of some types of chemical damage to DNA and DNA precursors; and (2) the processing of recombination i...

This paper reports reconstitution of 5'-nick-directed mismatch repair using purified human proteins. The reconstituted system includes MutSalpha or MutSbeta, MutLalpha, RPA, EXO1, HMGB1, PCNA, RFC, polymerase delta, and ligase I. In this system, MutSbeta plays a limited role in repair of base-base mismatches, but it processes insertion/deletion mispairs much more efficiently than MutSalpha, whi...

Sequence divergence acts as a potent barrier to homologous recombination; much of this barrier derives from an antirecombination activity exerted by mismatch repair proteins. An inverted repeat assay system with recombination substrates ranging in identity from 74% to 100% has been used to define the relationship between sequence divergence and the rate of mitotic crossing-over in yeast. To elu...

Fragile X-associated disorders are Repeat Expansion Diseases that result from expansion of a CGG/CCG-repeat in the FMR1 gene. Contractions of the repeat tract also occur, albeit at lower frequency. However, these contractions can potentially modulate disease symptoms or generate an allele with repeat numbers in the normal range. Little is known about the expansion mechanism and even less about ...

Typically disease-causing CAG/CTG repeats expand, but rare affected families can display high levels of contraction of the expanded repeat amongst offspring. Understanding instability is important since arresting expansions or enhancing contractions could be clinically beneficial. The MutSβ mismatch repair complex is required for CAG/CTG expansions in mice and patients. Oddly, by unknown mechan...