Drosophila Symplekin localizes dynamically to the histone locus body and tricellular junctions

The scaffolding protein Symplekin is part of multiple complexes involved in generating and modifying the 3' end of mRNAs, including cleavage-polyadenylation, histone pre-mRNA processing and cytoplasmic polyadenylation. To study these functions in vivo, we examined the localization of Symplekin during development and generated mutations of the Drosophila Symplekin gene. Mutations in Symplekin that reduce Symplekin protein levels alter the efficiency of both poly A+ and histone mRNA 3' end formation resulting in lethality or sterility. Histone mRNA synthesis takes place at the histone locus body (HLB) and requires a complex composed of Symplekin and several polyadenylation factors that associates with the U7 snRNP. Symplekin is present in the HLB in the early embryo when Cyclin E/Cdk2 is active and histone genes are expressed and is absent from the HLB in cells that have exited the cell cycle. During oogenesis, Symplekin is preferentially localized to HLBs during S-phase in endoreduplicating follicle cells when histone mRNA is synthesized. After the completion of endoreplication, Symplekin accumulates in the cytoplasm, in addition to the nucleoplasm, and localizes to tricellular junctions of the follicle cell epithelium. This localization depends on the RNA binding protein ypsilon schachtel. CPSF-73 and a number of mRNAs are localized at this same site, suggesting that Symplekin participates in cytoplasmic polyadenylation at tricellular junctions

The Femme Fatale in Vogue:Femininity Ideologies in Fin-de-siècle America

This article explores how marketing influences ideologies of femininity. Tracing the evolution of femme fatale images in Vogue magazine in 1890s America, we develop a typology around four archetypal forms of the femme fatale that prevailed during this period. In doing so we respond to calls for more critical historical analyses on femininity. While studies on masculinity ideologies proliferate, there is a paucity of research on dissonant representations of femininity in popular culture media. The femme fatale, often a self-determined seductress who causes anguish to the men who become involved with her, is an intriguing and enduring challenge to traditional notions of femininity. Thus, in studying the femme fatale in her historical context and revealing the multiplicity of feminine ideologies contained within this trope, we contribute to a deeper understanding of marketing’s role in both reflecting and reinforcing societal assumptions, attitudes and problematics around gender norms.</p

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Prophage Induction and Differential RecA and UmuDAb Transcriptome Regulation in the DNA Damage Responses of <i>Acinetobacter baumannii</i> and <i>Acinetobacter baylyi</i>

<div><p>The SOS response to DNA damage that induces up to 10% of the prokaryotic genome requires RecA action to relieve LexA transcriptional repression. In <i>Acinetobacter</i> species, which lack LexA, the error-prone polymerase accessory UmuDAb is instead required for <i>ddrR</i> induction after DNA damage, suggesting it might be a LexA analog. RNA-Seq experiments defined the DNA damage transcriptome (mitomycin C-induced) of wild type, <i>recA</i> and <i>umuDAb</i> mutant strains of both <i>A. baylyi</i> ADP1 and <i>A. baumannii</i> ATCC 17978. Of the typical SOS response genes, few were differentially regulated in these species; many were repressed or absent. A striking 38.4% of all ADP1 genes, and 11.4% of all 17978 genes, were repressed under these conditions. In <i>A. baylyi</i> ADP1, 66 genes (2.0% of the genome), including a CRISPR/Cas system, were DNA damage-induced, and belonged to four regulons defined by differential use of <i>recA</i> and <i>umuDAb</i>. In <i>A. baumannii</i> ATCC 17978, however, induction of 99% of the 152 mitomycin C-induced genes depended on <i>recA</i>, and only 28 of these genes required <i>umuDAb</i> for their induction. 90% of the induced <i>A. baumannii</i> genes were clustered in three prophage regions, and bacteriophage particles were observed after mitomycin C treatment. These prophages encoded <i>esvI</i>, <i>esvK1</i>, and <i>esvK2</i>, ethanol-stimulated virulence genes previously identified in a <i>Caenorhabditis elegans</i> model, as well as error-prone polymerase alleles. The induction of all 17978 error-prone polymerase alleles, whether prophage-encoded or not, was <i>recA</i> dependent, but only these DNA polymerase V-related genes were de-repressed in the <i>umuDAb</i> mutant in the absence of DNA damage. These results suggest that both species possess a robust and complex DNA damage response involving both <i>recA-</i>dependent and <i>recA</i>-independent regulons, and further demonstrates that although <i>umuDAb</i> has a specialized role in repressing error-prone polymerases, additional regulators likely participate in these species' transcriptional response to DNA damage.</p></div

Drosophila Symplekin localizes dynamically to the histone locus body and tricellular junctions

The scaffolding protein Symplekin is part of multiple complexes involved in generating and modifying the 3' end of mRNAs, including cleavage-polyadenylation, histone pre-mRNA processing and cytoplasmic polyadenylation. To study these functions in vivo, we examined the localization of Symplekin during development and generated mutations of the Drosophila Symplekin gene. Mutations in Symplekin that reduce Symplekin protein levels alter the efficiency of both poly A(+) and histone mRNA 3' end formation resulting in lethality or sterility. Histone mRNA synthesis takes place at the histone locus body (HLB) and requires a complex composed of Symplekin and several polyadenylation factors that associates with the U7 snRNP. Symplekin is present in the HLB in the early embryo when Cyclin E/Cdk2 is active and histone genes are expressed and is absent from the HLB in cells that have exited the cell cycle. During oogenesis, Symplekin is preferentially localized to HLBs during S-phase in endoreduplicating follicle cells when histone mRNA is synthesized. After the completion of endoreplication, Symplekin accumulates in the cytoplasm, in addition to the nucleoplasm, and localizes to tricellular junctions of the follicle cell epithelium. This localization depends on the RNA binding protein ypsilon schachtel. CPSF-73 and a number of mRNAs are localized at this same site, suggesting that Symplekin participates in cytoplasmic polyadenylation at tricellular junctions

Mitomycin-C induced and repressed SOS genes in ADP1 and 17978 differentially require RecA and UmuDAb.

<p>Gene induction ratios obtained from RNASeq transcriptome experiments are shown, with the induction (panel A) and repression (panel B) of canonical SOS genes. Gene names prefaced by “AD” indicate ADP1 genes; “AB” indicates 17978 genes, with A1S numbers of 17978 genes listed for <i>umuDC</i> alleles. The placement of the horizontal axis in each panel represents the cutoff level for a gene to be considered induced (A) or repressed (B). Bars above the horizontal axis indicate induced genes (panel A), and bars below the horizontal axis indicate repressed genes (panel B), with bars rising either below (panel A) or above (panel B) this axis to have lost their induction or repression, respectively, in the <i>umuDAb</i> and/or <i>recA</i> mutant strains. (A) Induced genes did not require <i>umuDAb</i> in either ADP1 or 17978, except for the category of <i>umuDC</i> alleles, and <i>recA</i> was required for all induced 17978 genes but only some induced ADP1 genes (<i>ruvA</i> and <i>uvrA</i>). (B) Repressed genes required only <i>umuDAb</i> in ADP1 but required both <i>umuDAb</i> and <i>recA</i> in 17978.</p

Drosophila Symplekin localizes dynamically to the histone locus body and tricellular junctions

Behavioral problems are multifactorial and includes perinatal, maternal, family, parenting, socio-economic and personal risk factors, but less is known about the association of postnatal heavy metals on children’s behavioral problems in Pacific Island children. Methods: A cohort of eligible nine-year-old children within a Pacific Island Families longitudinal study were recruited for a cross-sectional study. Child behavior problems were assessed using the child behavior checklist. Heavy metals (including Ni, Cu, Pb, Al, Cr and Cd) were determined in toenails, after acid digestion and analyzed using inductively coupled plasma mass spectrometry. Other factors such as lifestyle (smoking in pregnancy), health outcomes (obesity, health status), demographics (gender, ethnicity, parents’ marital status) and socioeconomic status (household income levels) were also collected. The statistical analysis included t-tests for independent sample and Mann–Whitney U-test, and chi-square or Fisher’s exact tests of independence for comparisons of the proportions. Regression models tested the hypothesized risk factors for behavior outcomes. Results: This observational study enrolled 278 eligible Pacific Island children living in Auckland, New Zealand. The prevalence of behavioral problems in the clinical range was high (22%) but there was no significant association between heavy metals in toenails and adverse behavioral outcomes. Conclusion: Regular monitoring and assessments of children for environmental risk factors, as well as social and lifestyle factors for behavior problems, continues. Alternative indicators of exposure to heavy metal should be evaluated

RT-qPCR experiments indicate that <i>umuDAb</i> is required for repression of error-prone polymerase components, not all DNA damage-induced genes.

<p>Delta Cq values from RT-qPCR experiments measuring expression of selected <i>A. baumannii</i> ATCC 17978 genes demonstrates the repressing activity of UmuDAb only for error prone polymerase components. The expression of each gene in both wild type and <i>umuDAb</i> null mutant is shown, with gene identity and A1S number listed on the x axis. Each gene was assayed in one RT-qPCR experiment (plate), with error bars indicating standard error of the mean from technical triplicates of biological triplicates.</p

Distribution of regulation mechanisms for mitomycin C-induced and repressed transcriptome in ADP1 and 17978.

<p>The absolute number of genes induced (A) or repressed (panel B) by MMC in the transcriptome of ADP1 and 17978 is shown. The designation of regulon is represented by the following terms: Neither (genes requiring neither <i>umuDAb</i> nor <i>recA</i> for regulation), Both (genes requiring both <i>umuDAb</i> and <i>recA</i> for regulation), RecA (genes requiring only <i>recA</i> for regulation), or UmuDAb (genes requiring only <i>umuDAb</i> for regulation). (A) Many more repressed genes were observed in ADP1 than 17978, with UmuDAb sufficing for this repression in most genes; 17978 repressed genes required either UmuDAb or both UmuDAb and RecA. (B) A greater number of induced genes was observed in 17978 than ADP1, and these genes required either RecA or both RecA and UmuDAb. In comparison, ADP1 induced genes belong to four regulons (Neither, Both, RecA, or UmuDAb).</p

Regulation and presence of canonical SOS genes in <i>Acinetobacter</i> species.

<p>* Four digit numbers correspond to A1S gene numbers in <i>A. baumannii</i>.</p