Conserved Small Nucleotidic Elements at the Origin of Concerted piRNA Biogenesis from Genes and lncRNAs.

PIWI-interacting RNAs (piRNAs) target transcripts by sequence complementarity serving as guides for RNA slicing in animal germ cells. The piRNA pathway is increasingly recognized as critical for essential cellular functions such as germline development and reproduction. In the ovary, as much as 11% of piRNAs map to protein-coding genes.

Lack of everolimus diffusion in pleural fluid during pleural progression of breast cancer: A case report.

Background: We report here a case where no everolimus pleural diffusion was evidenced at the same time of pleural progression of a metastatic breast cancer treated with everolimus and exemestane.

Case Description: A 69-year-old woman was diagnosed in October 2006 with stage III invasive ductal breast adenocarcinoma. After nine months of everolimus and exemestane treatment, she presented with a pleural progression.

Transposon Reactivation in the Germline May Be Useful for Both Transposons and Their Host Genomes.

Transposable elements (TEs) are long-term residents of eukaryotic genomes that make up a large portion of these genomes. They can be considered as perfectly fine members of genomes replicating with resident genes and being transmitted vertically to the next generation. However, unlike regular genes, TEs have the ability to send new copies to new sites.

piRNA precursors channel from the nucleus to the cytoplasm in a temporally regulated manner along oogenesis.

Background: PIWI-interacting RNAs (piRNAs) are the effectors of transposable element silencing in the reproductive apparatus. In ovarian somatic cells, piRNAs arise from long RNA precursors presumably processed within cytoplasmic Yb-bodies.

Results: Here we show that the nucleo-cytoplasmic traffic of piRNA precursors encoded by the locus is subjected to a spatio-temporal regulation.

Trapping a somatic endogenous retrovirus into a germline piRNA cluster immunizes the germline against further invasion.

Background: For species survival, the germline must faithfully transmit genetic information to the progeny. Transposable elements (TEs) constitute a significant threat to genome stability due to their mobility. In the metazoan germline, their mobilization is limited by a class of small RNAs called PIWI-interacting RNAs (piRNAs) produced by dedicated genomic loci called piRNA clusters.