A novel eukaryotic RdRP-dependent small RNA pathway represses antiviral immunity by controlling an ERK pathway component in the black-legged tick.

Small regulatory RNAs (sRNAs) are involved in antiviral defense and gene regulation. Although roles of RNA-dependent RNA Polymerases (RdRPs) in sRNA biology are extensively studied in nematodes, plants and fungi, understanding of RdRP homologs in other animals is still lacking. Here, we study sRNAs in the ISE6 cell line, which is derived from the black-legged tick, an important vector of human and animal pathogens.

A deeply conserved, noncanonical miRNA hosted by ribosomal DNA.

Advances in small RNA sequencing technologies and comparative genomics have fueled comprehensive microRNA (miRNA) gene annotations in humans and model organisms. Although new miRNAs continue to be discovered in recent years, these have universally been lowly expressed, recently evolved, and of debatable endogenous activity, leading to the general assumption that virtually all biologically important miRNAs have been identified. Here, we analyzed small RNAs that emanate from the highly repetitive rDNA arrays of Drosophila.

Argonaute-dependent small RNAs derived from single-stranded, non-structured precursors.

A general feature of Argonaute-dependent small RNAs is their base-paired precursor structures, and precursor duplex structures are often required for confident annotation of miRNA genes. However, this rule has been broken by discoveries of functional small RNA species whose precursors lack a predictable double-stranded (ds-) RNA structure, arguing that duplex structures are not prerequisite for small RNA loading to Argonautes. The biological significance of single-stranded (ss-) RNA loading has been recognized particularly in systems where active small RNA amplification mechanisms are involved, because even a small amount of RNA molecules can trigger the production of abundant RNA species leading to profound biological effects.

Human Wharton's jelly stem cells have unique transcriptome profiles compared to human embryonic stem cells and other mesenchymal stem cells.

The human umbilical cord that originates from the embryo is an extra-embryonic membrane and the Wharton's jelly within it is a rich source of stem cells (hWJSCs). It is not definitely known whether these cells behave as human embryonic stem cells (hESCs), human mesenchymal stem cells (hMSC) or both. They have the unique properties of high proliferation rates, wide multipotency, hypoimmunogenicity, do not induce teratomas and have anticancer properties.

A three dimensional anchorage independent in vitro system for the prolonged growth of embryoid bodies to study cancer cell behaviour and anticancer agents.

We describe a three dimensional (3D) anchorage independent in vitro protocol for the prolonged growth of human embryoid bodies (EBs) up to 90 days. We grew hESCs (46XX) in methylcellulose (MC) in motion culture in the presence of EB medium (EB), EB medium with Matrigel (EB + MAT), bulk culture medium (BCM), and BCM medium with Matrigel (BCM + MAT). All four experimental groups produced embryoid bodies (EBs) which with prolonged growth to 90 days acquired blood vessels and tissues from all three germ layers.