Y-linked iDmrt1 paralogue (iDMY) in the Eastern spiny lobster, Sagmariasus verreauxi: The first invertebrate sex-linked Dmrt

Sex determination pathways are extensively diverse across species, with the master sex-determinants being the most variable element. Despite this, there is a family of DM-domain transcription factors (Dmrts), which hold a highly conserved function in sexual development. This work is the first to describe a heterogametic sex-linked Dmrt in an invertebrate species, the Eastern spiny lobster, Sagmariasus verreauxi. We have termed the Y-linked, truncated paralogue of the autosomal iDmrt1, Sv-iDMY. Considering the master sex-determining function of both DMY in medaka and DM-W in frog, we hypothesised a similar function of Sv-iDMY. By conducting temporal expression analyses during embryogenesis we have identified a putative male sex-determining period during which iDMY>iDmrt1. Employing a GAL4-transactivation assay we then demonstrate the dominant negative suppression of iDMY over its autosomal iDmrt1 paralogue, suggesting the mechanism with which iDMY determines sex. Comparative analyses of Sv-iDMY, DM-W and medaka DMY, highlight the C′-mediated features of oligomerisation and transactivation as central to the mechanism that each exerts. Indeed, these features may underpin the plasticity facilitating the convergent emergence of these three sporadic sex-linked master-Dmrts

Applying the Power of Transcriptomics: Understanding Male Sexual Development in Decapod Crustacea

The decapod Crustacea are the most species-rich order of the Crustacea and include some of the most charismatic and highly valued commercial species. Thus the decapods draw a significant research interest in relation to aquaculture, as well as gaining a broader understanding of these species’ biology. However, the diverse physiology of the group considered with the lack of a model species have presented an obstacle for comparative analyses. In reflection of this, the recent integration of comparative transcriptomics has rapidly advanced our understanding of key regulatory pathways and developmental phenomena, an example being our understanding of sexual development. We discuss our work in the Eastern spiny lobster, Sagmariasus verreauxi, in the context of what is currently known about male sexual development in the decapods, highlighting the importance of transcriptomic techniques in achieving our recent advancements. We describe the progression made in our understanding of male sexual differentiation and maturation, as mediated by the insulin-like androgenic gland hormone (IAG), integrating the role of regulatory binding proteins (IGFBPs), a tyrosine kinase insulin receptor (TKIR), as well as the upstream effect of neuroendocrine hormones (GIH and MIH). We then consider the less well understood mechanism of male sex determination, with an emphasis on what we believe to be the key regulatory factors, the Dsx- and mab-3-related transcription factors (Dmrts). Finally, we discuss the function of the antennal gland (AnG) in sexual development, relating to the emergence of male-biased upregulation in the AnG in later sexual maturation and the sexually dimorphic expression of two key genes Sv-TKIR and Sv-Dmrt1. We then present the AnG as a case study to illustrate how comparative transcriptomic techniques can be applied to guide preliminary analyses, like the hypothesis that the AnG may function in pheromone biosynthesis. In summary, we describe the power of transcriptomics in facilitating the progress made in our understanding of male sexual development, as illustrated by the commercial decapod species, S. verreauxi. Considering future directions, we suggest that the integration of multiple omics-based techniques offers the most powerful tool to ensure we continue to piece together the biology of the important group of decapod Crustacea

Molecular aspects of eye development and regeneration in the Australian redclaw crayfish, Cherax quadricarinatus

The compound eye evolved over 500 million years ago and enables mosaic vision in most arthropod species. The molecular regulation of the development of the compound eye has been primarily studied in the fruit fly Drosophila melanogaster. However, due to the nature of holometabolous insects halting growth after their terminal metamorphosis into the adult form, they lack the capacity to regenerate. Crustaceans, unlike holometabolous insects, continue to grow during adulthood, achieved through regular shedding of their exoskeleton, in a cyclic process known as molting. This therefore offers crustaceans as a highly suitable model to study ocular regeneration in the adult arthropod eye. We have assessed the regenerative capacity of the retinal section of the Cherax quadricarinatus (red-claw crayfish) eye, following ablation and successive post-metamorphic molts. This work then provides a transcriptomic description of the outer, pigmented retinal tissue (the ommatidia and lamina ganglionaris) and the basal, non-pigmented neuroendocrine ocular tissue (the X-organ Sinus Gland complex, hemiellipsoid body and optic nerve). Using comparative analysis, we identified all the transcripts in the C. quadricarinatus ocular transcriptome that are known to function in compound eye development in D. melanogaster. Differentially and uniquely transcribed genes of the retina are described, suggesting proposed mechanisms that may regulate ocular regeneration in decapod Crustacea. This research exemplifies the application C. quadricarinatus holds as an optimal model to study the regulation of ocular regeneration. Further in-depth transcriptomic analyses are now required, sampled throughout the regeneration process to better define the regulatory mechanism

Intrinsic ripples in graphene

The stability of two-dimensional (2D) layers and membranes is subject of a long standing theoretical debate. According to the so called Mermin-Wagner theorem, long wavelength fluctuations destroy the long-range order for 2D crystals. Similarly, 2D membranes embedded in a 3D space have a tendency to be crumpled. These dangerous fluctuations can, however, be suppressed by anharmonic coupling between bending and stretching modes making that a two-dimensional membrane can exist but should present strong height fluctuations. The discovery of graphene, the first truly 2D crystal and the recent experimental observation of ripples in freely hanging graphene makes these issues especially important. Beside the academic interest, understanding the mechanisms of stability of graphene is crucial for understanding electronic transport in this material that is attracting so much interest for its unusual Dirac spectrum and electronic properties. Here we address the nature of these height fluctuations by means of straightforward atomistic Monte Carlo simulations based on a very accurate many-body interatomic potential for carbon. We find that ripples spontaneously appear due to thermal fluctuations with a size distribution peaked around 70 \AA which is compatible with experimental findings (50-100 \AA) but not with the current understanding of stability of flexible membranes. This unexpected result seems to be due to the multiplicity of chemical bonding in carbon.Comment: 14 pages, 6 figure

A primer to common major gastrointestinal post-surgical anatomy on CT—a pictorial review

The post-operative abdomen can be challenging and knowledge of normal post-operative anatomy is important for diagnosing complications. The aim of this pictorial essay is to describe a few selected common, major gastrointestinal surgeries, their clinical indications and depict their normal post-operative computed tomography (CT) appearance. This essay provides some clues to identify the surgeries, which can be helpful especially when surgical history is lacking: recognition of the organ(s) involved, determination of what was resected and familiarity with the type of anastomoses used

Impact of Insecticides on Parasitoids of the Leafminer, Liriomyza trifolii, in Pepper in South Texas

Liriomyza leafminers (Diptera: Agromyzidae) are cosmopolitan, polyphagous pests of horticultural plants and many are resistant to insecticides. Producers in South Texas rely on insecticides as the primary management tool for leafminers, and several compounds are available. The objective of this study is to address the efficacy of these compounds for controlling Liriomyza while minimizing their effects against natural enemies. Research plots were established at Texas AgriLife research center at Weslaco, Texas in fall 2007 and spring 2008 seasons, and peppers were used as a model crop. Plots were sprayed with novaluron, abamectin, spinetoram, lambda-cyhalothrin and water as treatments according to leafminer infestation; insecticide efficacy was monitored by collecting leaves and infested foliage. Plant phenology was also monitored. Novaluron was the most effective insecticide and lambda-cyhalothrin showed resurgence in leafminer density in fall 2007 and no reduction in spring 2008. Other compounds varied in efficacy. Novaluron showed the least number of parasitoids per leafminer larva and the lowest parasitoid diversity index among treatments followed by spinetoram. Liriomyza trifolii (Burgess) was the sole leafminer species on peppers, and 19 parasitoid species were found associated with this leafminer. Application of these insecticides for management of leafminers with conservation of natural enemies is discussed

Multi-tissue transcriptome analysis identifies key sexual development-related genes of the ornate spiny lobster (Panulirus ornatus)

Sexual development involves the successive and overlapping processes of sex determination, sexual differentiation, and ultimately sexual maturation, enabling animals to reproduce. This provides a mechanism for enriched genetic variation which enables populations to withstand ever-changing environments, selecting for adapted individuals and driving speciation. The molecular mechanisms of sexual development display a bewildering diversity, even in closely related taxa. Many sex determination mechanisms across animals include the key family of “doublesex- and male abnormal3-related transcription factors” (Dmrts). In a few exceptional species, a single Dmrt residing on a sex chromosome acts as the master sex regulator. In this study, we provide compelling evidence for this model of sex determination in the ornate spiny lobster Panulius ornatus, concurrent with recent reports in the eastern spiny lobster Sagmariasus verreauxi. Using a multi-tissue transcriptomic database established for P. ornatus, we screened for the key factors associated with sexual development (by homology search and using previous knowledge of these factors from related species), providing an in-depth understanding of sexual development in decapods. Further research has the potential to close significant gaps in our understanding of reproductive development in this ecologically and commercially significant order

'Mutations in LAMB2 associate with albuminuria and Optic Nerve Hypoplasia with Hypopituitarism'

CONTEXT: Mutations in LAMB2, encoding the basement membrane protein, laminin β2, are associated with an autosomal recessive disorder characterized by congenital nephrotic syndrome, ocular abnormalities and neurodevelopmental delay (Pierson Syndrome). CASE DESCRIPTION: This report describes a twelve year old boy with short stature, visual impairment and developmental delay who presented with macroscopic haematuria and albuminuria. He had isolated growth hormone deficiency, optic nerve hypoplasia and a small anterior pituitary with corpus callosum dysgenesis on his cranial MRI, thereby supporting a diagnosis of optic nerve hypoplasia syndrome. Renal histopathology revealed focal segmental glomerulosclerosis. Using next generation sequencing on a targeted gene panel for steroid resistant nephrotic syndrome, compound heterozygous missense mutations were identified in LAMB2 [c.737G>A p.Arg246Gln, c.3982G>C p.Gly1328Arg]. Immunohistochemical analysis revealed reduced glomerular laminin β2 expression compared to control kidney and a thin basement membrane on electron microscopy. Laminin β2 is expressed during pituitary development and Lamb2-/- mice exhibit stunted growth, abnormal neural retinae and here, we show, abnormal parenchyma of the anterior pituitary gland. CONCLUSION: We propose that patients with genetically undefined optic nerve hypoplasia syndrome should be screened for albuminuria and if present, screened for mutations in LAMB2

A standardised bioassay method using a bench‐top spray tower to evaluate entomopathogenic fungi for control of the greenhouse whitefly, Trialeurodes vaporariorum

BACKGROUND: Bioassays evaluating entomopathogenic fungi (EPF) isolates for effective microbial control of whitefly are a fundamental part of the screening process for bioprotectants, but development of repeatable, robust bioassays is not straightforward. Currently, there is no readily available standardised method to test the efficacy of EPF on whitefly. Here, we describe the calibration and use of a spray tower to deliver a standardised protocol to assess EPF activity; the method was validated using 18 EPF from four genera in tests against greenhouse whitefly, Trialeurodes vaporariorum (Westwood). RESULTS: At 138 kPa, the sprayer delivered 0.062 mL mm−2 (620 L ha−1) and an even deposition of spray across the central 1590 mm2 of the spray area. Average conidial deposition for all EPF was 252 conidia mm−2 and equivalent to 2.5 × 1012 conidia ha−1 at an application concentration of 1 × 107 conidia mL−1. Conidial deposition of a test Beauveria bassiana suspension increased with increasing application concentration. Egg laying by T. vaporariorum adults was restricted to 177 mm2 using clip cages specifically designed to ensure that third‐instar T. vaporariorum received a uniform spray coverage. Nymphs occupied 373 ± 5 mm2 of the leaf after migrating during the first instar. Average T. vaporariorum mortality totaled 8–89% 14 days after application of 1 × 107 conidia mL−1 of each EPF isolate. CONCLUSION: Combining the calibrated sprayer and bioassay method provides a reliable, standardised approach to test the virulence of EPF against whitefly nymphs. This laboratory‐based assay is affordable, replicable and allows the user to alter the dose of conidia applied to the target

Technology Contribution to Improve Autistic Children Life Quality

To review published literature on the use of technology and how it has improved autistic children life style. A systematic review of the English literature was performed using the PRISMA guideline. Papers indexed in WOS and Scopus databases were included, adjusted to a timeline between 2016 and 2020 and focused on mobile technology, interventions, improvement of social behavior and communication and autism, aimed to describe the most used mechanism to improve autistic life style. Thirty two (32) papers were included in the review. We obtained 14 papers on the Scopus database and 18 on the WOS database. The majority of studies evidenced the use of virtual reality, mobile devices, video modelling and robots as the most common applications for autism therapies. Technology has caused an improvement in autistic children life quality. The development of mobile applications, virtual reality applications and robots have showed a positive impact reflected in the performance of daily activities and a better understanding of how they feel, how to behave, how to express themselves and interact with others. Technology gives the opportunity to monitor children status; and offers adaptability, safety, and accuracy of the information