Distinct expression of two Drosophila homologs of fibroblast growth factor receptors in imaginai discs

AbstractThe expression of two Drosophila homologs of FGF receptors (DRF1 and DRF2) in imaginal discs was studied. DFR1 mRNA was observed in several imaginal discs, whereas DFR2 mRNA was not detected. DFR1 expression in the wing and leg discs took place in probable myoblasts in a pattern similar to that of twist, a mesodermal gene. The mRNA was also detected in the morphogenetic furrow and its posterior region of the eye disc and around the proliferation center of the brain. These results suggest that DFR1 is involved in the development of mesodermal and neuronal cells constituting the adult body

Identification of four FGF receptor genes in Medaka fish (Oryzias latipes)

AbstractFour types of cDNA clones encoding tyrosine kinases highly homologous to mammalian fibroblast growth factor receptors (FGF-R) were isolated from Medaka fish (Oryzias latipes) by the reverse transcription-polymerase chain reaction. Comparison of the four deduced amino acid sequences with four known mammalian FGF-Rs indicated that four FGF-R species corresponding to mammalian FGF-Rs exist universally in vertebrates including fishes, although FGF-R4 might have diverged sequences between fishes and mammals. Each of four FGF-R genes is transcribed to various extents as multiple mRNAs possibly by alternative splicing in adult fishes

Essential Notes Regarding the Design of Functional siRNAs for Efficient Mammalian RNAi

Short interfering RNAs (siRNAs) are widely used to bring about RNA interference (RNAi) in mammalian cells. Numerous siRNAs may be designed for any target gene though most of which would be incapable of efficiently inducing mammalian RNAi. Certain highly functional siRNAs designed for knockout of a particular gene may render unrelated endogenous genes nonfunctional. These major bottlenecks should be properly eliminated when RNAi technologies are employed for any experiment in mammalian functional genomics. This paper thus presents essential notes and findings regarding the proper choice of siRNA-sequence selection algorithms and web-based online software systems

siVirus: web-based antiviral siRNA design software for highly divergent viral sequences

siVirus () is a web-based online software system that provides efficient short interfering RNA (siRNA) design for antiviral RNA interference (RNAi). siVirus searches for functional, off-target minimized siRNAs targeting highly conserved regions of divergent viral sequences. These siRNAs are expected to resist viral mutational escape, since their highly conserved targets likely contain structurally/functionally constrained elements. siVirus will be a useful tool for designing optimal siRNAs targeting highly divergent pathogens, including human immunodeficiency virus (HIV), hepatitis C virus (HCV), influenza virus and SARS coronavirus, all of which pose enormous threats to global human health

Optimal design and validation of antiviral siRNA for targeting HIV-1

We propose rational designing of antiviral short-interfering RNA (siRNA) targeting highly divergent HIV-1. In this study, conserved regions within HIV-1 genomes were identified through an exhaustive computational analysis, and the functionality of siRNAs targeting the highest possible conserved regions was validated. We present several promising antiviral siRNA candidates that effectively inhibited multiple subtypes of HIV-1 by targeting the best conserved regions in pandemic HIV-1 group M strains

Inducible expression of double-stranded RNA reveals a role for dFADD in the regulation of the antibacterial response in Drosophila adults

In Drosophila, the immune deficiency (Imd) pathway controls antibacterial peptide gene expression in the fat body in response to Gram-negative bacterial infection. The ultimate target of the Imd pathway is Relish, a transactivator related to mammalian P105 and P100 NF-kappaB precursors. Relish is processed in order to translocate to the nucleus, and this cleavage is dependent on both Dredd, an apical caspase related to caspase-8 of mammals, and the fly Ikappa-B kinase complex (dmIKK). dTAK1, a MAPKKK, functions upstream of the dmIKK complex and downstream of Imd, a protein with a death domain similar to that of mammalian receptor interacting protein (RIP). Finally, the peptidoglycan recognition protein-LC (PGRP-LC) acts upstream of Imd and probably functions as a receptor for the Imd pathway. Using inducible expression of dFADD double-stranded RNA, we demonstrate that dFADD is a novel component of the Imd pathway: dFADD double-stranded RNA expression reduces the induction of antibacterial peptide-encoding genes after infection and renders the fly susceptible to Gram-negative bacterial infection. Epistatic studies indicate that dFADD acts between Imd and Dredd. Our results reinforce the parallels between the Imd and the TNF-R1 pathways

RNAi-Mediated Knockdown Showing Impaired Cell Survival in Drosophila Wing Imaginal Disc

The genetically amenable organism Drosophila melanogaster has been estimated to have 14,076 protein coding genes in the genome, according to the flybase release note R5.13 (http://flybase.bio.indiana.edu/static_pages/docs/release_notes.html). Recent application of RNA interference (RNAi) to the study of developmental biology in Drosophila has enabled us to carry out a systematic investigation of genes affecting various specific phenotypes. In order to search for genes supporting cell survival, we conducted an immunohistochemical examination in which the RNAi of 2,497 genes was independently induced within the dorsal compartment of the wing imaginal disc. Under these conditions, the activities of a stress-activated protein kinase JNK (c-Jun N-terminal kinase) and apoptosis-executing factor Caspase-3 were monitored. Approximately half of the genes displayed a strong JNK or Caspase-3 activation when their RNAi was induced. Most of the JNK activation accompanied Caspase-3 activation, while the opposite did not hold true. Interestingly, the area activating Caspase-3 was more broadly seen than that activating JNK, suggesting that JNK is crucial for induction of non-autonomous apoptosis in many cases. Furthermore, the RNAi of essential factors commonly regulating transcription and translation showed a severe and cell-autonomous apoptosis but also elicited another apoptosis at an adjacent area in a non-autonomous way. We also found that the frequency of apoptosis varies depending on the tissues