Quantification of allele-specific expression of a gene encoding strawberry polygalacturonase-inhibiting protein (PGIP) using Pyrosequencing((TM))

Recent studies indicate that allele-specific differences in gene expression are a common phenomenon. The extent to which differential allelic expression exists might be underestimated, due to the limited accuracy of the methods used so far. To demonstrate allele-specific expression, we investigated the transcript abundance of six individual, highly homologous alleles of a polygalacturonase-inhibiting protein gene (FaPGIP) from octoploid strawberry (Fragaria × ananassa). We applied the highly quantitative Pyrosequencing method which, for the gene under study, detected allele frequency differences as small as 4.0 ± 2.8%. Pyrosequencing of RT-PCR products showed that one FaPGIP allele was preferentially expressed in leaf tissue, while two other alleles were expressed in a fruit-specific way. For fruits that were inoculated with Botrytis cinerea a strong increase in overall FaPGIP gene expression was observed. This upregulation was accompanied by a significant change in FaPGIP allele frequencies when compared with non-treated fruits. Remarkably, in the five cultivars tested, the allele frequency in cDNA from the inoculated fruits was similar to that in genomic DNA, suggesting uniform upregulation of all FaPGIP alleles present as a result of pathogenesis-related stress. The results demonstrate that when Pyrosequencing of RT-PCR products is performed, novel allele-specific gene regulation can be detected and quantifie

A gene encoding a polygalacturonase-inhibiting protein (PGIP) shows developmental regulation and pathogen-induced expression in strawberry

Polygalacturonase-inhibiting proteins (PGIPs) have been demonstrated to play a role in host defence in several plants. The PGIP now cloned from strawberry (Fragaria ananassa) showed a high degree of homology to other fruit PGIPs. The gene expression of strawberry PGIP was monitored in healthy leaves, flowers and fruit at different maturity stages. PGIP transcript levels were also analysed following fruit inoculation with the fungal pathogen Botrytis cinerea in strawberry cultivars displaying variation in susceptibility. Healthy mature berries showed the highest constitutive PGIP gene expression levels compared with leaves, flowers and immature fruit, indicating that the gene is developmentally regulated. Among the cultivars studied ('Elsanta', 'Korona', 'Polka', 'Senga sengana', 'Tenira'), 'Polka' had the highest constitutive expression level of PGIP. After inoculation with B. cinerea, all five cultivars displayed a significant induction of PGIP gene expression, but the differences between them were not statistically significant. The high induction of the PGIP gene after inoculation with B. cinerea indicates that PGIP has a role in defence of strawberr

Self-help countermeasure strategies for populations living within contaminated areas of Belarus, Russia and Ukraine

Countermeasures have been effectively employed within intensive agricultural systems in areas of the Former Soviet Union (FSU) affected by the Chernobyl accident. However, ingestion doses continue to be elevated in some areas as are sult of few foodstuffs which are collected from the wild or produced by the household. Forest fungi and berries, and milk from privately owned cattle are the most notable contributors to 137Cs intakes amongst these foodstuffs. In this paper we consider advice which would help affected populations to both understand the importance of these exposure routes and to reduce their exposure. In addition to the potential radiological benefits, self-help schemes are highly cost-effective and likely to have a positive psychological influence on populations living within contaminated areas of the FSU. Evidence to suggest that the transfer of radiocaesium to cow milk is considerably higher in the FSU than within western Europe and North America is discussed