The transcription factor Xrp1 is required for PERK-mediated antioxidant gene induction in Drosophila.

PERK is an endoplasmic reticulum (ER) transmembrane sensor that phosphorylates eIF2α to initiate the Unfolded Protein Response (UPR). eIF2α phosphorylation promotes stress-responsive gene expression most notably through the transcription factor ATF4 that contains a regulatory 5' leader. Possible PERK effectors other than ATF4 remain poorly understood. Here, we report that the bZIP transcription factor Xrp1 is required for ATF4-independent PERK signaling. Cell-type-specific gene expression profiling in Drosophila indicated that delta-family glutathione-S-transferases (gstD) are prominently induced by the UPR-activating transgene Rh1G69D. Perk was necessary and sufficient for such gstD induction, but ATF4 was not required. Instead, Perk and other regulators of eIF2α phosphorylation regulated Xrp1 protein levels to induce gstDs. The Xrp1 5' leader has a conserved upstream Open Reading Frame (uORF) analogous to those that regulate ATF4 translation. The gstD-GFP reporter induction required putative Xrp1 binding sites. These results indicate that antioxidant genes are highly induced by a previously unrecognized UPR signaling axis consisting of PERK and Xrp1.

Meningeal Granular Cell Tumour in a Green Tree Python (Morelia viridis).

Granular cell tumours (GCTs) are uncommon neoplasms mostly reported in man, dogs and horses. The origin of GCT is thought to be Schwann cells, with the associated characteristics of neural crest morphology. Neoplastic cells often demonstrate positive immunoreactivity for S100, LC3, vimentin and p62. They are also periodic acid-Schiff (PAS) positive and diastase resistant. A female green tree python (Morelia viridis) was presented for severe constipation and hyporexia of 4 month's duration and, despite treatment, died the next day. A 4.8 × 3.4 mm intracalvarial GCT was identified, compressing the overlying cerebrum without invasion. Neoplastic cells were immunoreactive to S100 and had brightly eosinophilic cytoplasmic granules that were PAS positive and diastase resistant. Electron microscopy revealed numerous cytoplasmic lysosomes in neoplastic cells. GCTs are reported rarely in non-mammalian species with three reports in birds. This represents the first report of a GCT in a reptile.

A Comparison of Inpatient and Outpatient-Based Chemotherapy Regimens for the Treatment of Acute Myeloid Leukaemia In The Elderly.

INTRODUCTION: Acute myeloid leukaemia (AML) is an aggressive haematological malignancy which is more common in the elderly and has a poor 5-year survival. There are no established beneficial interventions to treat AML in elderly patients. It is unclear whether outpatient delivery of palliative chemotherapies could reduce the burden of disease and hospitalisation for this group. AIMS: To compare overall survival, response to treatment and supportive care needs between inpatient and outpatient-based treatments for AML in elderly patients. MATERIALS & METHODS: We undertook a retrospective cohort study in the Haematology Department at Belfast City Hospital comparing overall survival (OS), treatment responses and supportive care needs between inpatient and outpatient treatments for AML in elderly patients. Consecutive entrants to outpatient and inpatient based clinical trials between February 2013 and January 2017 were included. Case notes, chemotherapy charts, clinic letters, blood bank and electronic care records were analysed. RESULTS: OS and rates of CR (complete remission), CRi (CR with incomplete count recovery) and PR (partial response) was not significantly different between inpatient and outpatient regimens with a median OS of 201 vs. 124 days, respectively. No response was observed in 35% of patients in the inpatient group compared with 65% of the outpatient group, however this did not reach significance. Of patients who achieved CR/CRi in the outpatient group, 75% relapsed at a median of 271 days, compared with 60% of the inpatient group at a median of 209 days. At least one grade 3-4 toxicity was experienced by 90% and 83.3% of inpatient and outpatient groups, respectively. There was no difference in six common grade 3-4 toxicities. Patients on the outpatient regimen spent fewer days in hospital but had a median packed red cell use of more than twice that of the inpatient group. No difference was noted in infections, days on antibiotics or platelet use. DISCUSSION: Our data suggests that outpatient chemotherapy is safe and can reduce hospitalisation for elderly patients with AML, without a decline in OS or response rates. These results provide an important rationale to test the comparative efficacy of outpatient chemotherapy. Chemotherapy related toxicities remain a significant source of morbidity in this population and highlight the need to develop novel, targeted therapies for this age group.

Have Niche, Will Travel. New Means of Linking Diet and Ecomorphology Reveals Niche Conservatism in Freshwater Cottoid Fishes.

Evolutionary transitions between habitats have been catalysts for some of the most stunning examples of adaptive diversification, with novel niches and new resources providing ecological opportunity for such radiations. In aquatic animals, transitions from saltwater to freshwater habitats are rare, but occur often enough that in the Neotropics for example, marine-derived fishes contribute noticeably to regional ichthyofaunal diversity. Here, we investigate how morphology has evolved in a group of temperate fishes that contain a marine to freshwater transition: the sculpins (Percomorpha; Cottoidea). We devised a novel method for classifying dietary niche and relating functional aspects of prey to their predators. Coupled with functional measurements of the jaw apparatus in cottoids, we explored whether freshwater sculpins have fundamentally changed their niche after invading freshwater (niche lability) or if they retain a niche similar to their marine cousins (niche conservatism). Freshwater sculpins exhibit both phylogeographical and ecological signals of phylogenetic niche conservatism, meaning that regardless of habitat, sculpins fill similar niche roles in either saltwater or freshwater. Rather than competition guiding niche conservatism in freshwater cottoids, we argue that strong intrinsic constraints on morphological and ecological evolution are at play, contra to other studies of diversification in marine-derived freshwater fishes. However, several intertidal and subtidal sculpins as well as several pelagic freshwater species from Lake Baikal show remarkable departures from the typical sculpin bauplan. Our method of prey categorization provides an explicit, quantitative means of classifying dietary niche for macroevolutionary studies, rather than relying on somewhat arbitrary means used in previous literature.

Tem Nicho, Viaja. Novos Meios de Associar Dieta e Ecomorfologia Revelam Conservadorismo de Nicho em Peixes Cotoides de Água Doce (Have Niche, Will Travel. New Means of Linking Diet and Ecomorphology Reveals Niche Conservatism in Freshwater Cottoid Fishes) Transições evolutivas entre habitats têm sido catalisadores de alguns dos mais impressionantes exemplos de diversificação adaptativa, com novos nichos e recursos proporcionando oportunidade ecológica para tais radiações. Em animais aquáticos, as transições de água salgada para habitats de água doce são raras, mas ocorrem com freqüência suficiente para que, nos Neotrópicos, por exemplo, os peixes marinhos contribuam notavelmente para a diversidade regional da ictiofauna. Aqui, nós investigamos como a morfologia evoluiu em um grupo de peixes temperados que contêm uma transição marinha para a água doce: os esculpentes (Percomorpha; Cottoidea). Nós concebemos um novo método para classificar o nicho alimentar e relacionar os aspectos funcionais das presas aos seus predadores. Juntamente com medidas funcionais do aparato de mandíbula em cotoides, exploramos se os esculpentes de água doce mudaram fundamentalmente seu nicho depois de invadi-la (labilidade de nicho) ou se eles mantêm um nicho semelhante aos seus primos marinhos (conservadorismo de nicho). Os esculpentes de água doce exibem sinais filogeográficos e ecológicos de conservadorismo filogenético de nicho, o que significa que, independente do habitat, os esculpentes preenchem papéis ecológicos semelhantes em água salgada ou doce. Mais do que a concorrência guiando o conservadorismo de nicho em cotoides de água doce, argumentamos que fortes restrições intrínsecas à evolução morfológica e ecológica estão em jogo, em contraste com outros estudos de diversificação em peixes de água doce derivados do mar. No entanto, vários esculpentes intertidais e subtidais, bem como várias espécies pelágicas de água doce do Lago Baikal, mostram notáveis desvios do típico bauplan dos esculpentes. Nosso método de categorização de presas fornece um modo explícito e quantitativo de classificar o nicho alimentar para estudos macroevolutivos ao invéz de depender de meios arbitrários usados na literatura anterior. Translated to Portuguese by G. Sobral (gabisobral@gmail.com).

PeerWise provides significant academic benefits to biological science students across diverse learning tasks, but with minimal instructor intervention.

We demonstrate that student engagement with PeerWise, an online tool that allows students to author and answer multiple-choice questions (MCQs), is associated with enhanced academic performance across diverse assessment types on a second year Genetics course. Benefits were consistent over three course deliveries, with differential benefits bestowed on groups of different prior ability. A rating scheme, to assess the educational quality of students' questions, is presented and demonstrates that our students are able intuitively to make such quality assessments, and that the process of authoring high quality questions alone does not explain the academic benefits. We further test the benefits of providing additional PeerWise support and conclude that PeerWise works efficiently with minimal intervention, and can be reliably assessed using automatically generated PeerWise scores.

Acute myeloid leukemia with concurrent myeloid sarcoma treated with autologous bone marrow transplantation: two illustrative cases and a literature review.

Myeloid sarcoma (MS) is an invasive extramedullary solid tumor composed of immature cells of the myeloid series. It complicates the clinical course of a minority of patients with acute myeloid leukemia (AML). Traditionally its presence has been regarded as an indicator of aggressive disease. Currently, the optimal treatment of AML with concurrent MS remains to be determined. We report two cases of autologous bone marrow transplantation (auto-BMT) for AML with concurrent MS followed by a review of the literature.

Diabetes in a high secure hospital.

AIMS: To determine the prevalence of diabetes mellitus and its possible causes and to assess its control in a high secure hospital. METHODS: A cross sectional survey and a prospective cohort study were conducted. The cross sectional survey included 408 patients admitted under the Mental Health Act, and the prospective study included 22 patients with known diabetes followed up for 24 months. The outcome measures evaluated were drug treatment, status of microvascular and macrovascular complications, glycated haemoglobin, and body mass index. RESULTS: In the cross sectional survey, 35 out of 408 patients (8.6%; 95% confidence interval 5.9% to 11.3%) had known diabetes, and all of these had type 2 diabetes. Obesity, cigarette smoking, schizophrenia, and antipsychotic drug use were frequent, and weight gain was common after hospital admission. Glycaemic control was variable, and, although a majority of patients were above recommended treatment targets, control remained stable over the follow up period. CONCLUSIONS: Type 2 diabetes was common in this hospital. Both its prevalence and the suboptimal glycaemic control in some patients probably relate to sedentary life, dietary factors, smoking, and perhaps widespread use of antipsychotic drugs. However, regular multidisciplinary input enabled most patients to maintain relatively stable glycaemic control, with good control of blood pressure and lipids, at levels similar to those seen in community and hospital diabetic clinics. Further modification of lifestyle risk factors is probably needed to reduce the prevalence and impact of diabetes in this patient group.

An inventory of long-lived radionuclides residual from underground nuclear testing at the Nevada test site, 1951-1992.

An inventory of long-lived radionuclides produced by 828 underground nuclear tests conducted at the Nevada test site (NTS) from 1951 to 1992 includes residual tritium, fission products, actinides, and activation products. Recently, the US Department of Energy approved the declassification of the NTS radionuclide inventory by principal geographic test centers. This permits unclassified publication of radionuclide totals for the Yucca Flat, Pahute Mesa-Area 19, Pahute Mesa-Area 20, Frenchman Flat, and Rainier Mesa/Shoshone Mountain testing locations. Activities are reported as of September 23, 1992, the date of the last underground nuclear test conducted at the NTS, and September 23, 2492, after 500 years of radioactive decay. The availability of these data affords an opportunity for the analysis of the radiologic source term within the boundaries of local hydrogeologic units and provides insight to where radionuclides are sited relative to potential exposure pathways.

UbcD4, a ubiquitin-conjugating enzyme in Drosophila melanogaster expressed in pole cells.

The ability to destroy a particular protein at a particular time is central to the regulation of many cellular processes. Selective proteolysis in eukaryotic cells is carried out primarily by the ubiquitin-proteasome pathway. Attachment of a ubiquitin polymer to an unwanted protein causes it to be degraded by the proteasome. Several classes of enzyme, known as E1s, E2s and E3s, control the stepwise formation of a ubiquitin-protein conjugate. The specificity of substrate selection lies with the E2s and E3s. Here we describe the cloning of a Drosophila E2 gene, UbcD4, which is only expressed in embryos. Its expression pattern in stage 10-11 embryos suggests a role in germ cell development. UbcD4 can interact with the polyubiquitin-binding subunit of the proteasome.

Genital schistosomiasis.

Schistosomiasis is the most serious helminthic infection in the United Kingdom. Female genital schistosomiasis affects 9-13 million women worldwide, mainly in areas where Schistosoma haematobium is endemic. With increasing tourism to these areas, this diagnosis is being encountered more frequently in the West. We present 2 cases of vulval schistosomiasis that were presented to our department in 1999 and 2000.

DNA-binding activity and subunit interaction of the mariner transposase.

Mos1 is a member of the mariner/Tc1 family of transposable elements originally identified in Drosophila mauritiana. It has 28 bp terminal inverted repeats and like other elements of this type it transposes by a cut and paste mechanism, inserts at TA dinucleotides and codes for a transposase. This is the only protein required for transposition in vitro. We have investigated the DNA binding properties of Mos1 transposase and the role of transposase-transposase interactions in transposition. Purified transposase recognises the terminal inverted repeats of Mos1 due to a DNA-binding domain in the N-terminal 120 amino acids. This requires a putative helix-turn-helix motif between residues 88 and 108. Binding is preferentially to the right hand end, which differs at four positions from the repeat at the left end. Cleavage of Mos1 by transposase is also preferentially at the right hand end. Wild-type transposase monomers interact with each other in a yeast two-hybrid assay and we have used this to isolate mutations resulting in reduced interaction. These mutations lie along the length of the protein, indicating that transposase-transposase interactions are not due to a single interaction domain. One such mutation which retains both DNA-binding and catalytic activity has greatly reduced ability to excise Mos1 from plasmid DNA through coordinate cleavage of the two ends and transposition in vitro is lowered to a level 20-fold below that of the wild-type. This suggests that transposase-transposase interaction is required to form a synaptic complex necessary for coordinate cleavage at the ends of Mos1 during transposition. This mutant enzyme allows insertion at dinucleotides other than TA, including sequences with GC base pairs. This is the first example of a mariner/Tc1 transposase with altered target specificity.

Drosophila homolog of the myotonic dystrophy-associated gene, SIX5, is required for muscle and gonad development.

SIX5 belongs to a family of highly conserved homeodomain transcription factors implicated in development and disease. The mammalian SIX5/SIX4 gene pair is likely to be involved in the development of mesodermal structures. Moreover, a variety of data have implicated human SIX5 dysfunction as a contributor to myotonic dystrophy type 1 (DM1), a condition characterized by a number of pathologies including muscle defects and testicular atrophy. However, this link remains controversial. Here, we investigate the Drosophila gene, D-Six4, which is the closest homolog to SIX5 of the three Drosophila Six family members. We show by mutant analysis that D-Six4 is required for the normal development of muscle and the mesodermal component of the gonad. Moreover, adult males with defective D-Six4 genes exhibit testicular reduction. We propose that D-Six4 directly or indirectly regulates genes involved in the cell recognition events required for myoblast fusion and the germline:soma interaction. While the exact phenotypic relationship between D-Six4 and SIX4/5 remains to be elucidated, the defects in D-Six4 mutant flies suggest that human SIX5 should be more strongly considered as being responsible for the muscle wasting and testicular atrophy phenotypes in DM1.

Genome evolution: sex and the transposable element.

Mating systems are thought to play an important role in determining the fate of genomic parasites such as transposable elements. This is supported by recent studies which indicate that asexual genomes may be structured very differently to those of sexual species.

Retrotransposition of the I factor, a non-long terminal repeat retrotransposon of Drosophila, generates tandem repeats at the 3' end.

Non-long terminal repeat (LTR) retrotransposons or LINEs transpose by reverse transcription of an RNA intermediate and are thought to use the 3' hydroxyl of a chromosomal cleavage to initiate synthesis of the first strand of the cDNA. Many of them terminate in a poly(dA) sequence at the 3' end of the coding strand although some, like the I factor of Drosophila melanogaster, have 3' ends formed by repeats of the trinucleotide TAA. We report results showing that I factor transcripts end a few nucleotides downstream of the TAA repeats and that these extra nucleotides are not integrated into chromosomal DNA during retrotransposition. We also show that the TAA repeats are not required for transposition and that I elements containing mutations affecting the TAA sequences generate transposed copies ending with tandem repeats of various types. Our results suggest that during integration the 3' end of the I factor RNA template can pair with nucleotides at the target site and that tandem duplications are generated by the reverse transcriptase of the I factor in a manner that is reminiscent of the activity of the reverse transcriptases of telomerases. Reverse transcriptases of other non-LTR retrotransposons may function in a similar way.

Pogo transposase contains a putative helix-turn-helix DNA binding domain that recognises a 12 bp sequence within the terminal inverted repeats.

Pogo is a transposable element with short terminal inverted repeats. It contains two open reading frames that are joined by splicing and code for the putative pogo transposase, the sequence of which indicates that it is related to the transposases of members of the Tc1/mariner family as well as proteins that have no known transposase activity including the centromere binding protein CENP-B. We have shown that the N-terminal region of pogo transposase binds in a sequence-specific manner to the ends of pogo and have identified residues essential for this. The results are consistent with a prediction that DNA binding is due to a helix-turn-helix motif within this region. The transposase recognises a 12 bp sequence, two copies of which are present at each end of pogo DNA. The outer two copies occur as inverted repeats 14 nucleotides from each end of the element, and contain a single base mismatch and indicate the inverted repeats of pogo are 26 nucleotides long. The inner copies occur as direct repeats, also with a single mismatch.

Transposition of the Drosophila element mariner into the chicken germ line.

The ability of the Drosophila transposable element mariner to transpose in the chicken was tested using a plasmid carrying an active mariner element injected into chick zygotes. Surviving embryos and chicks were analyzed for presence of mariner. Analysis of embryos that survived for at least 12 days of development indicated that mariner had transposed at high frequency into the chicken genome. Germline transmission of mariner from one of three surviving birds confirmed transposition. Analysis of the first-generation (G1) chicks showed that they each contained between one and three copies of mariner. Six different transposition events were represented in the G1 birds, and the transposition was catalyzed by expression of the mariner element's transposase gene. Transmission from G1 to G2 occurred at a 1:1 ratio. Mariner therefore has potential for development as a vector for transgenesis in avian species.

Copy number control of a transposable element, the I factor, a LINE-like element in Drosophila.

The I factor is a LINE-like transposable element in Drosophila. Most strains of Drosophila melanogaster, inducer strains, contain 10-15 copies of the I factor per haploid genome located in the euchromatic regions of the chromosome arms. These are not present in a few strains known as reactive strains. I factors transpose at low frequency in inducer strains but at high frequency in the female progeny of crosses between reactive and inducer flies. We have found that the activity of the I factor promoter is sensitive to the number of copies of the first 186 nucleotides of the I factor sequence, which constitutes the 5'-untranslated region. The activity of the I factor decreases as the copy number of this sequence increases.

A LINE-like transposable element in Drosophila, the I factor, encodes a protein with properties similar to those of retroviral nucleocapsids.

I factors are members of the LINE-like family of transposable elements and move by reverse transcription of an RNA intermediate. Complete I factors contain two open reading frames. The amino acid sequence encoded by the first of these, ORF1, includes the motif CX2CX4HX4C that is characteristic of the nucleocapsid domain of retroviral gag polypeptides followed by a copy of the slightly different sequences CX2CX4HX6C and CX2CX9HX6C. The function of this protein is unknown. We have expressed this protein in Escherichia coli and Spodoptera frugiperda cells and have shown that it binds both DNA and RNA but without any evidence for sequence specificity. The properties of deletion derivatives of the protein indicate that more than one region is responsible for DNA binding and that the CCHC motif is not essential for this. The ORF1 protein expressed in either E. coli or Spodoptera cells forms high molecular weight structures that require the region of the protein including the CCHC motif for their formation. This protein can also accelerate the annealing of complementary single-stranded oligonucleotides. These results suggest that this protein may associate with the RNA transposition intermediates of the I factor to form particles that enter the nucleus during transposition and that it may stimulate both the priming of reverse transcription and integration. This may be generally true for the product of the first open reading frame of LINE-like elements.

Transposable elements: how non-LTR retrotransposons do it.

The source of the enzyme activity responsible for the transposition of retrotransposons of the type that lack terminal repeats has at last been identified: in L1Hs elements, it is encoded by the second open reading frame and is a nuclease related to the apurinic repair endonucleases.