Gene Regulation in Giardia lambia Involves a Putative MicroRNA Derived from a Small Nucleolar RNA

Two core microRNA (miRNA) pathway proteins, Dicer and Argonaute, are found in Giardia lamblia, a deeply branching parasitic protozoan. There are, however, no apparent homologues of Drosha or Exportin5 in the genome. Here, we report a 26 nucleotide (nt) RNA derived from a 106 nt Box C/D snoRNA, GlsR2. This small RNA, designated miR5, localizes to the 3′ end of GlsR2 and has a 75 nt hairpin precursor. GlsR2 is processed by the Dicer from Giardia (GlDcr) and generated miR5. Immunoprecipitation of the Argonaute from Giardia (GlAgo) brought down miR5. When a Renilla Luciferase transcript with a 26 nt miR5 antisense sequence at the 3′-untranslated region (3′ UTR) was introduced into Giardia trophozoites, Luciferase expression was reduced ∼25% when synthetic miR5 was also introduced. The Luciferase mRNA level remained, however, unchanged, suggesting translation repression by miR5. This inhibition was fully reversed by introducing also a 2′-O-methylated antisense inhibitor of miR5, suggesting that miR5 acts by interacting specifically with the antisense sequence in the mRNA. A partial antisense knock down of GlDcr or GlAgo in Giardia indicated that the former is needed for miR5 biogenesis whereas the latter is required for miR5-mediated translational repression. Potential targets for miR5 with canonical seed sequences were predicted bioinformatically near the stop codon of Giardia mRNAs. Four out of the 21 most likely targets were tested in the Luciferase reporter assay. miR5 was found to inhibit Luciferase expression (∼20%) of transcripts carrying these potential target sites, indicating that snoRNA-derived miRNA can regulate the expression of multiple genes in Giardia

Uridylation and adenylation of RNAs

The posttranscriptional addition of nontemplated nucleotides to the 3′ ends of RNA molecules can have a significant impact on their stability and biological function. It has been recently discovered that nontemplated addition of uridine or adenosine to the 3′ ends of RNAs occurs in different organisms ranging from algae to humans, and on different kinds of RNAs, such as histone mRNAs, mRNA fragments, U6 snRNA, mature small RNAs and their precursors etc. These modifications may lead to different outcomes, such as increasing RNA decay, promoting or inhibiting RNA processing, or changing RNA activity. Growing pieces of evidence have revealed that such modifications can be RNA sequence-specific and subjected to temporal or spatial regulation in development. RNA tailing and its outcomes have been associated with human diseases such as cancer. Here, we review recent developments in RNA uridylation and adenylation and discuss the future prospects in this research area

Hanno: Experimental Investigation of Gyoki Impacting on the HumanHeart Rate Variability and the Autonomic Nervous System

International audienc

What can optical engineers learn from Leonardo?

Optics in general is an old science. Many brilliant researchers have created both theory and practice in this field. Some of their achievements are still in use, some are unjustly forgotten. In this paper we tried to rethink some points of ancient scientists to show that they had «seeds» which are still important ourdays. In particular, the applicability of the "golden section" from nature to the modern, computational process of optical system design was tested experimentally. Design principles, current challenges, possible solutions and some applications are discussed. They could be used, for example, in optical design, at the stage of starting scheme or help making decision of optical system producibility

Dynamic optimization of optical design process by means of producibility modulations

In this paper, PanDao is used dynamically in the early stage of the optical design process so that manufacturability aspects can be considered during the process

Manufacturing risk management in optical design

This paper reports on strategies to determine optimal sets of optical fabrication technologies (OFT) for given optical elements, to be applied in optical fabrication chains. For this purpose, optical systems are categorized and linked to critical characteristics of optical fabrication technologies, which are determined by a methodical analysis of their processing parameters

SPDT and standard CNC-grinding of tungsten carbide molds for precision glass molding: An experimental process analysis

The contents of this work are based on [1], [2] and [3]. Using the three wagons approach, critical parameters were identified and the process window of ductile machining was considerably enlarged. This made it possible to increase the critical depth of cut, which is ten times greater than predicted by the Bifano formula. A new formula to describe the machining process was developed and verified experimentally. In addition, the level of surface roughness (Sq) generated in ductile mode was analyzed and a formula was generated that allows roughness prediction depending on the critical process parameters. Finally, both formulas were used to create optimized sets of process parameters that produce a "first light" in ductile machining for a) single point diamond turning (SPDT) on ultra-precision machines (UPM) of binder-free carbide form and b) non-UPM, standard CNC ductile grinding of WC and glass

In-process surface roughness measuring device for information-based real-time polishing process adjustment and optimization

In this paper we present a feasible variant of a device for in-process roughness measurement during an optical polishing process. The system, already presented as Tirm respectively I-Tirm, has been technically varied and can now be integrated into almost any lever polishing process with little effort. This enables new possibilities regarding real-time optical manufacturing process monitoring and optimization. © 2021 SPIE.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]