The silencing of one parental set of rRNA genes in a genetic hybrid is an epigenetic phenomenon known as nucleolar dominance. We showed previously that silencing is restricted to the nucleolus organizer regions (NORs), the loci where rRNA genes are tandemly arrayed, and does not spread to or from neighboring protein-coding genes. One hypothesis is that nucleolar dominance is the net result of h...

E-cadherin is among tumor suppressor genes which mostly subjects to the down-regulation in squamous cell carcinoma of esophagus (SCCE). The gene is tightly associated with the tumor invasion and metastasis in multiple human cancers, especially SCCE. CpG islands’ methylation in the promoter region of E-cadherin is among the mechanisms that have been suggested for the E-cadherin silencing, howeve...

The Sleeping Beauty (SB) transposon represents an important vehicle for in vivo gene delivery because it can efficiently and stably integrate into mammalian genomes. In this report, we examined transposon expression in human cells using a novel nonselective fluorescence-activated cell sorter-based method and discovered that SB integrates approximately 20 times more frequently than previously re...

RNA silencing has become a major focus of molecular biology and biomedical research around the world. This is highlighted by a simple PubMed search for ‘‘RNA silencing,’’ which retrieves almost 9,000 articles. Interest in gene silencing-related mechanisms stemmed from the early 1990s, when this phenomenon was first noted as a surprise observation by plant scientists during the course of plant t...

RNA silencing describes the sequence specific degradation of RNA targets. Silencing is a non-cell autonomous event that is graft transmissible in different plant species. The present study is the first report on systemic acquired dsRNA-mediated gene silencing of transgenic and endogenous gene sequences in a woody plant like apple. Transgenic apple plants overexpressing a hairpin gene construct ...

Posttranscriptional gene silencing is a defense mechanism in plants that is similar to quelling in fungi and RNA interference in animals. Here, we describe four genetic loci that are required for posttranscriptional gene silencing in Arabidopsis. One of these, SDE1, is a plant homolog of QDE-1 in Neurospora crassa that encodes an RNA-dependent RNA polymerase. The sde1 mutation was specific for ...

We report a new mechanism in carcinogenesis involving coordinate long-range epigenetic gene silencing. Epigenetic silencing in cancer has always been envisaged as a local event silencing discrete genes. However, in this study of silencing in colorectal cancer, we found common repression of the entire 4-Mb band of chromosome 2q.14.2, associated with global methylation of histone H3 Lys9. DNA hyp...

Although the word ‘revolution’ should not be used lightly in science, there is no other way to describe the recent explosion in our awareness and understanding of RNAmediated gene silencing pathways. The central player in RNA-mediated gene silencing is a double-stranded RNA (dsRNA) that is chopped into tiny RNAs by the enzyme Dicer. The tiny RNAs associate with various silencing effector comple...

Polycomb group (PcG) and trithorax (trxG) proteins are evolutionary conserved factors that contribute to cell fate determination maintenance of cellular identities during development multicellular organisms. The PcG maintains heritable patterns gene silencing while trxG acts as anti-silencing by conserving activation type specific genes. Genetic molecular analysis has revealed extensive details...