No abstract

No abstract

BackgroundThe prevalence and the role of AGG interruptions within the FMR1 gene in the normal population is unknown. In this study, we investigated the frequent of AGG loss, in one or two alleles within the normal population. The role of AGG in the FMR1 stability has been assessed by correlating AGG loss to the prevalence of premutation/full mutation in two ethnic groups differing in their consanguinity rate: high versus low consanguinity rate (HCR vs. LCR).MethodsThe CGG repeat allele size and AGG presence were measured in 6,865 and 6,204 females belonging to the LCR (5%) and HCR (>45%) groups, respectively, by Tripled‐Primed‐PCR technique.ResultsA lower prevalence of the premutation was observed in the HCR (1:158) as compared to the LCR group (1:128). No full mutation was found in the HCR females while in the LCR group the prevalence found was 1:1,149. Homozygosity rate was higher in the HCR population compared to the LCR group.The overall AGG loss was higher in the HCR population than in the LCR and increased with increased CGG repeat number in both ethnic groups.ConclusionsAlthough we observed a significantly higher rate of homozygosity and AGG loss in the HCR group, this did not affect the prevalence of the premutation and full mutation in this population. Their prevalence was significantly lower than in the LCR population. Finally, we discuss whether the loss of AGG could be also a polymorphic event but not only a stabilizing factor.

No abstract

The dicentric chromosome assay (DCA), is considered the 'gold standard' for radiation biodosimetry. Yet, DCA, as currently implemented, may be impractical for emergency response applications, especially when time is of the essence, owing to its labor-intensive and time-consuming nature. The growth of a primary lymphocyte culture for 48h in-vitro is required for DCA, and manual scoring of dicentric chromosomes (DCs) requires an additional 24-48h, resulting in an overall processing time of 72-96h for dose estimation.In order to improve this timing. we introduce a protocol that will detect the metaphase cells in a population of cells, and then will harvest only those metaphase cells. Our metaphase enrichment approach is based on xed human lymphocytes incubated with monoclonal, anti-phosphorylated H3 histone (ser 10). Antibodies against this histone have been shown to be speci c for mitotic cells. Colcemid is used to arrest the mitotic cells in metaphase. Following that, a ow-cytometric sorting apparatus isolates the mitotic fraction from a large population of cells, in a few minutes. These mitotic cells are then spread onto a slide and treated with our C-Banding procedure [Gonen et al. 2022], to visualize the centromeres with DAPI. This reduces the chemical processing time to approximately 2 hours. This reduces the time required for the DCA and makes it practical for a much wider set of applications, such as emergency response following exposure of a large population to ionizing radiation.