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Early onset parkinsonism (EOP) has been associated with mutations in the Parkin, PINK1, and DJ- 1 genes. We studied the prevalence of mutations in all three genes in 127 unrelated Chinese patients with apparently sporadic EOP using direct sequencing analysis and real-time quantitative PCR analysis assay. There are 16 patients (12.6%) with mutations of Parkin gene, four patients (3.1%) with mutations of PINK1 gene, and three patients (2.4%) with mutation of DJ- 1 gene. In conclusion, Parkin gene mutation is the most common pathogenic factor in Chinese patients with sporadic EOP. Mutations of DJ- 1 and PINK1 gene are also found in Chinese patients with sporadic EOP. [ABSTRACT FROM AUTHOR]

This review covers the O antigens of the 46 serotypes of Shigella, but those of most Shigella flexneri are variants of one basic structure, leaving 34 Shigella distinct O antigens to review, together with their gene clusters. Several of the structures and gene clusters are reported for the first time and this is the first such group for which structures and DNA sequences have been determined for all O antigens. Shigella strains are in effect Escherichia coli with a specific mode of pathogenicity, and 18 of the 34 O antigens are also found in traditional E. coli. Three are very similar to E. coli O antigens and 13 are unique to Shigella strains. The O antigen of Shigella sonnei is quite atypical for E. coli and is thought to have transferred from Plesiomonas. The other 12 O antigens unique to Shigella strains have structures that are typical of E. coli, but there are considerably more anomalies in their gene clusters, probably reflecting recent modification of the structures. Having the complete set of structures and genes opens the way for experimental studies on the role of this diversity in pathogenicity. [ABSTRACT FROM AUTHOR]

Background: Loss of heterozygosity (LOH) at 13q22 is a common event in nasopharyngeal carcinoma (NPC). EDNRB gene located at 13q22 has been demonstrated to be hypermethylated in some kinds of tumors. In the current study, we focused on the epigenetic and genetic alterations of EDNRB in NPC. Methods: The mRNA expression of EDNRB was detected by semiquantitative RT-PCR and real-time quantitative PCR in 49 NPC and 12 chronic nasopharyngitis biopsies. The methylation and LOH status of EDNRB were examined by methylation-specific polymerase chain reaction, microsatellite PCR and sequencing. We also examined the mRNA expression of EDNRB in four NPC cell lines after 5-aza-2′-deoxycytidine treatment. Results:EDNRB was downregulated in primary NPC tissues and NPC cell lines, and a relatively higher methylation level of EDNRB was found in NPC biopsies (84%) compared to that in chronic nasopharyngitis biopsies (42%). Treatment of NPC cell lines with 5-aza-2′-deoxycytidine activated EDNRB expression. LOH of EDNRB gene was also found at two microsatellite sites with ratios of 6.25 and 16.67% in NPC. Conclusion: Our results suggested that EDNRB expression may be affected by aberrant promoter methylation and gene deletion and may play a role in the development of NPC. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Streptomyces coelicolor A3(2) does not have a canonical cell division cycle during most of its complex life cycle, yet it contains a gene (FtsKSC) encoding a protein similar to FtsK, which couples the completion of cell division and chromosome segregation in unicellular bacteria such as Escherichia coli. Here, we show that various constructed FtsKSC mutants all grew apparently normally and sporulated but upon restreaking gave rise to many aberrant colonies and to high frequencies of chloramphenicol-sensitive mutants, a phenotype previously associated with large terminal deletions from the linear chromosome. Indeed, most of the aberrant colonies had lost large fragments near one or both chromosomal termini, as if chromosome ends had failed to reach their prespore destination before the closure of sporulation septa. A constructed FtsKSC-enhanced green fluorescent protein fusion protein was particularly abundant in aerial hyphae, forming distinctive complexes before localizing to each sporulation septum, suggesting a role for FtsKSC in chromosome segregation during sporulation. Use of a fluorescent reporter showed that when FtsKSC was deleted, several spore compartments in most spore chains failed to express the late-sporulation-specific sigma factor gene sigF, even though they contained chromosomal DNA. This suggested that sigF expression is autonomously activated in each spore compartment in response to completion of chromosome transfer, which would be a previously unknown checkpoint for late-sporulation-specific gene expression. These results provide new insight into the genetic instability prevalent among streptomycetes, including those used in the industrial production of antibiotics. [ABSTRACT FROM AUTHOR]

The article presents a study that investigates the structure of the O-antigen of Salmonella O66 and the differences and similarities between the O-antigens of Salmonella O66 and Escherichia coli O166. It states that the O-antigen of Salmonella O66 differs from those of Escherichia coli O166 in one linkage and O-acetylation. The study has found out that the O-antigen gene clusters of Escherichia coli O166 and Salmonella O66 have similar organizations, except in their wzy genes.