46 research outputs found

    Industrial Melanism in the Peppered Moth Is Not Associated with Genetic Variation in Canonical Melanisation Gene Candidates

    Get PDF
    Industrial melanism in the peppered moth (Biston betularia) is an iconic case study of ecological genetics but the molecular identity of the gene determining the difference between the typical and melanic (carbonaria) morphs is entirely unknown. We applied the candidate gene approach to look for associations between genetic polymorphisms within sixteen a priori melanisation gene candidates and the carbonaria morph. The genes were isolated and sequence characterised in B. betularia using degenerate PCR and from whole-transcriptome sequence. The list of candidates contains all the genes previously implicated in melanisation pattern differences in other insects, including aaNAT, DOPA-decarboxylase, ebony, tan, tyrosine hydroxylase, yellow and yellow2 (yellow-fa). Co-segregation of candidate gene alleles and carbonaria morph was tested in 73 offspring of a carbonaria male-typical female backcross. Surprisingly, none of the sixteen candidate genes was in close linkage with the locus controlling the carbonaria-typical polymorphism. Our study demonstrates that the ‘carbonaria gene’ is not a structural variant of a canonical melanisation pathway gene, neither is it a cis-regulatory element of these enzyme-coding genes. The implication is either that we have failed to characterize an unknown enzyme-coding gene in the melanisation pathway, or more likely, that the ‘carbonaria gene’ is a higher level trans-acting factor which regulates the spatial expression of one or more of the melanisation candidates in this study to alter the pattern of melanin production

    A Simple Supramolecular Approach to Recycling Rare Earth Elements

    Get PDF
    The rapid increase in demand for rare-earth elements reflects their crucial roles in climate critical technologies. However, the lack of simple solutions for the separation of these metals from waste materials and ores represents a significant barrier to sustainable and environmentally benign rare-earth production. We report the application of a supramolecular approach to this challenge, using a triamido-arene receptor to selectively precipitate f-elements through their encapsulation as hexanitratometalates. Single-step, near quantitative recovery of Nd/Pr directly from magnet scrap was observed without the need for pH adjustment or pretreatment of the acidic leach solution. The rare-earth nitrate was rapidly stripped from the host−guest precipitate with water and the receptor recycled for further use. Near quantitative and highly selective uptake of La−Nd and Th from lateritic rare-earth ores was also achieved with no uptake of any non-f-element. These results show that targeting f-element metalates in separations chemistry can deliver exceptional and unique selectivity that may have significant consequences in the sustainable production of the rare-earth elements

    Recessive Z-linked lethals and the retention of haplotype diversity in a captive butterfly population

    Get PDF
    Sex chromosomes are predicted to harbour elevated levels of sexually antagonistic variation due to asymmetries in the heritability of recessive traits in the homogametic versus heterogametic sex. This evolutionary dynamic may manifest as high recessive load specifically affecting the homogametic sex, and the retention of haplotype diversity in small populations. We tested the hypothesis that the Z chromosome in the butterfly Bicyclus anynana carries a high inbred load for male fertility and viability. Homozygosity of Z chromosome blocks was produced by daughter–father backcrosses, and inferred from marker loci positioned via a linkage map. Male sterility was, in general, unrelated to homozygosity in any region of the Z, but there was an extreme deficit of homozygous males within a 2 cM interval in all families. In contrast, no corresponding skew in Z genotype was detected in their (hemizygous) sisters. The same pattern was observed in historically inbred lines, indicating a high frequency of recessive lethals in the ancestral population. Allele-frequency changes between 1993 and 2006 (70 generations at Ne ~ 160) show that, despite the loss of many haplotypes, diversity was retained significantly above the neutral expectation. Effective overdominance in the lethal region can account for this effect locally but not in other parts of the chromosome, that are also associated with persistent linkage disequilibrium. These unexpected patterns suggest the operation of other factors, such as epistatic selection, recombination suppression, assortative mating and meiotic drive. Our results highlight the role of balancing selection in maintaining the inbred load and linked genetic diversity

    Cerium (IV) Oxide Reinforced Lithium-Borotellurite Glasses: A Characterization Study Through Physical, Optical, Structural and Radiation Shielding Properties

    Full text link
    The purpose of this study was to characterize the structural, optical, and physical properties of various kinds of glasses based on the 50TeO2–30B2O3-(20-x)Li2O-xCeO2 system (x = 0, 0.5, 1, 2, 3, 4, 5, 10, 15, 20). Consequently, ten glass samples were produced by melting-annealing. Calculations of the densities of the synthesized glasses were performed using the Archimedes technique. The sample's structural, optical, physical, and radiation interaction properties were determined using XRD analysis, Raman spectroscopy, and advanced modelling techniques with FLUKA code, yielding optical band gap, refractive index, and Urbach energy values. By increasing the CeO2 reinforcement from 0 to 20 mol %, the glass densities rose from 4.0614 to 4.7519 g cm−3. The transmittance spectra of TBLC glasses were found in the range of 200–1100 nm. Our findings showed that the lowest Urbach energy belonged to the TBLC1 sample, and the highest Urbach energy belonged to the TBLC20 sample. When the CeO2 ratio was raised, the optical transmittance and absorption characteristics changed nearly monotonically, suggesting that these qualities may be calculated and controlled using the CeO2 additive, as shown in this experiment. By substituting CeO2 for Li2O inside the structure, it was possible to substantially enhance the optical band gap. Additionally, at simulated energies greater than 0.02 MeV, the gamma-ray linear attenuation coefficient rises monotonically with CeO2 reinforcement. Consequently, linear attenuation coefficients were reported as 125.843 cm−1, 127.601 cm−1, 129.211 cm−1, 132.312 cm−1, 135.166 cm−1, 138.705 cm−1, 141.288 cm−1, 156.690 cm−1, 172.393 cm−1, 186.811 cm−1 for TBLC0, TBLC0.5, TBLC1, TBLC2, TBLC3, TBLC4, TBLC5, TBL10, TBLC15 and TBLC20 at 0.015 MeV, respectively. It can be concluded that combination of high-concentration CeO2 and TeO2–B2O3 glass is an excellent synergetic tool for combining structural, optical, and radiation properties when combined with other materials. © 2021 Elsevier Ltd and Techna Group S.r.l.The research activity is supported by Eskisehir Osmangazi University, Scientific Research Council with grant number 202019D20

    A high-coverage draft genome of the mycalesine butterfly <i>Bicyclus anynana</i>

    Get PDF
    The mycalesine butterfly Bicyclus anynana, the "Squinting bush brown," is a model organism in the study of lepidopteran ecology, development, and evolution. Here, we present a draft genome sequence for B. anynana to serve as a genomics resource for current and future studies of this important model species. Seven libraries with insert sizes ranging from 350 bp to 20 kb were constructed using DNA from an inbred female and sequenced using both Illumina and PacBio technology; 128 Gb of raw Illumina data was filtered to 124 Gb and assembled to a final size of 475 Mb (∼×260 assembly coverage). Contigs were scaffolded using mate-pair, transcriptome, and PacBio data into 10 800 sequences with an N50 of 638 kb (longest scaffold 5 Mb). The genome is comprised of 26% repetitive elements and encodes a total of 22 642 predicted protein-coding genes. Recovery of a BUSCO set of core metazoan genes was almost complete (98%). Overall, these metrics compare well with other recently published lepidopteran genomes. We report a high-quality draft genome sequence for Bicyclus anynana. The genome assembly and annotated gene models are available at LepBase (http://ensembl.lepbase.org/index.html)

    Recovering individual haplotypes and a contiguous genome assembly from pooled long-read sequencing of the diamondback moth (Lepidoptera: Plutellidae).

    Get PDF
    The assembly of divergent haplotypes using noisy long-read data presents a challenge to the reconstruction of haploid genome assemblies, due to overlapping distributions of technical sequencing error, intra-locus genetic variation and inter-locus similarity within these data. Here we present a comparative analysis of assembly algorithms representing overlap-layout-consensus, repeat graph and de Brujn graph methods. We examine how post-processing strategies attempting to reduce redundant heterozygosity interact with the choice of initial assembly algorithm and ultimately produce a series of chromosome-level assemblies for an agricultural pest, the diamondback moth, Plutella xylostella (L.). We compare evaluation methods and show that BUSCO analyses may overestimate haplotig removal processing in long-read draft genomes, in comparison to a k-mer method. We discuss the trade-offs inherent in assembly algorithm and curation choices and suggest that "best practice" is research question dependent. We demonstrate a link between allelic divergence and allele-derived contig redundancy in final genome assemblies and document the patterns of coding and non-coding diversity between redundant sequences. We also document a link between an excess of non-synonymous polymorphism and haplotigs that are unresolved by assembly or post-assembly algorithms. Finally, we discuss how this phenomenon may have relevance for the usage of noisy long-read genome assemblies in comparative genomics

    Structural Characterization and Gamma-Ray Attenuation Properties of Rice-Like α-TeO2 Crystalline Microstructures (CMS) Grown Rapidly on Free Surface of Tellurite-Based Glasses

    Full text link
    In this study, we extensively analyzed the structural, physical and gamma-ray attenuation properties of α-TeO2 CMS, which has unexpectedly been observed as a part of Sm2O3 doped TeO2–B2O3–V2O5 glasses synthesis process. The shape of α-TeO2 CMS was obtained from SEM analyses. Moreover, EDX, XRD and Raman examinations were utilized for systematic characterization of α-TeO2 CMS. In addition to experimental physical and structural studies on α-TeO2 CMSs, gamma-ray attenuation properties were also determined and compared with Quartz and some novel glasses such as PNCKM5, C25, SCNZ7 along with some commercial glasses such as RS253, RS253G18, RS323G19, RS360, RS520 using FLUKA general-purpose Monte Carlo code. EDX results indicated that only Te and O elements were available in the α-TeO2 CMS. The finding showed that gamma-ray attenuation competencies of α-TeO2 CMS is higher than many novel and commercial glasses in addition to traditional concrete shields. It can be concluded that further comparison studies can be done between normal glass structure and α-TeO2 CMS (or similar) occurred glass structures in terms of better understanding the total gamma-ray attenuation and the effect of α-TeO2 CMS. © 2021 The Author(s).The authors thank Taif University Researchers Supporting Project number (TURSP-2020/12), Taif University, Taif, Saudi Arabia. The APC was covered by "Dunarea de Jos" University of Galati, Romania

    Destruction of chemical warfare surrogates using a portable atmospheric pressure plasma jet

    Get PDF
    Today’s reality is connected with mitigation of threats from the new chemical and biological warfare agents. A novel investigation of cold plasmas in contact with liquids presented in this paper demonstrated that the chemically reactive environment produced by atmospheric pressure plasma jet (APPJ) is potentially capable of rapid destruction of chemical warfare agents in a broad spectrum. The decontamination of three different chemical warfare agent surrogates dissolved in liquid is investigated by using an easily transportable APPJ. The jet is powered by a kHz signal source connected to a low-voltage DC source and with He as working gas. The detailed investigation of electrical properties is performed for various plasmas at different distances from the sample. The measurements of plasma properties in situ are supported by the optical spectrometry measurements, whereas the high performance liquid chromatography measurements before and after the treatment of aqueous solutions of Malathion, Fenitrothion and Dimethyl Methylphosphonate. These solutions are used to evaluate destruction and its efficiency for specific neural agent simulants. The particular removal rates are found to be from 56% up to 96% during 10 min treatment. The data obtained provide basis to evaluate APPJ’s efficiency at different operating conditions. The presented results are promising and could be improved with different operating conditions and optimization of the decontamination process

    Advancing our understanding of functional genome organisation through studies in the fission yeast

    Get PDF
    Significant progress has been made in understanding the functional organisation of the cell nucleus. Still many questions remain to be answered about the relationship between the spatial organisation of the nucleus and the regulation of the genome function. There are many conflicting data in the field making it very difficult to merge published results on mammalian cells into one model on subnuclear chromatin organisation. The fission yeast, Schizosaccharomyces pombe, over the last decades has emerged as a valuable model organism in understanding basic biological mechanisms, especially the cell cycle and chromosome biology. In this review we describe and compare the nuclear organisation in mammalian and fission yeast cells. We believe that fission yeast is a good tool to resolve at least some of the contradictions and unanswered questions concerning functional nuclear architecture, since S. pombe has chromosomes structurally similar to that of human. S. pombe also has the advantage over higher eukaryotes in that the genome can easily be manipulated via homologous recombination making it possible to integrate the tools needed for visualisation of chromosomes using live-cell microscopy. Classical genetic experiments can be used to elucidate what factors are involved in a certain mechanism. The knowledge we have gained during the last few years indicates similarities between the genome organisation in fission yeast and mammalian cells. We therefore propose the use of fission yeast for further advancement of our understanding of functional nuclear organisation
    corecore