Phenotypic Plasticity of Feeding Structures in Marine Invertebrate Larvae

2018 ◽  
Keyword(s):  
Phenotypic Plasticity ◽  
Molecular Mechanisms ◽  
Sea Urchins ◽  
Marine Invertebrate ◽  
Future Research ◽  
Trade Offs ◽  
Feeding Structure ◽  
Research Findings ◽  
Planktotrophic Larvae ◽  
Invertebrate Larvae

Nearly three decades ago, biologists discovered that planktotrophic larvae of sea urchins can alter the size of their ciliated feeding structures in response to the concentration of food (i.e., unicellular algae). In the years since, this response has become one of the best-studied examples of phenotypic plasticity in marine organisms. Researchers have found that this form of plasticity occurs widely among different types of feeding larvae in several phyla, and involves energetic trade-offs with a suite of correlated life history characters. Furthermore, investigators have recently started to unravel the genetic and molecular mechanisms underlying this plasticity. We review the literature on feeding-structure plasticity in marine invertebrate larvae. We highlight the diversity of species and variety of experimental designs and statistical methodologies, summarize research findings to draw more general conclusions, and target promising directions for future research.

scholarly journals A microbial perspective on the life-history evolution of marine invertebrate larvae: if, where, and when to feed

2017 ◽  
Author(s):  
Tyler J. Carrier ◽  
Jason Macrander ◽  
Adam M. Reitzel
Keyword(s):  
Life History ◽  
Marine Invertebrate ◽  
Life History Evolution ◽  
Trade Offs ◽  
Pelagic Environment ◽  
History Evolution ◽  
Planktotrophic Larvae ◽  
Invertebrate Larvae ◽  
Microbiome Data ◽  
Feeding Environments

AbstractThe feeding environment for planktotrophic larvae has a major impact on development and progression towards competency for metamorphosis. High phytoplankton environments that promote growth often have a greater microbial load and incidence of pathogenic microbes, while areas with lower food availability have a lower number of potential pathogens. Trade-offs between metabolic processes associated with growth and immune functionality have been described throughout the animal kingdom and may influence the life-history evolution of marine invertebrate planktotrophic larvae in these environments. Namely, to avoid potential incidences of microbial-mediated mortality and/or dysbiosis, larvae should regulate time spent between these two feeding environments. We describe here transcriptomic and microbiome data that supports this trade-off in larvae, where larvae in a well-fed environment upregulate genes associated with metabolism and may regularly enter a state of dysbiosis, resulting in mortality. To address the hypothesis that the environmental microbiota is a selective force on if, where, and when planktotrophic larvae should feed, we present a strategy for determining the specific interactions of larvae and microbes at a scale representative of their larger pelagic environment.

Physiology of Larval Feeding

2018 ◽  
Keyword(s):  
Growth And Development ◽  
Marine Invertebrate ◽  
Larval Growth ◽  
Circulatory System ◽  
Future Research ◽  
Larval Feeding ◽  
Digestive Physiology ◽  
Larval Body ◽  
The Individual ◽  
Invertebrate Larvae

The functional properties of marine invertebrate larvae represent the sum of the physiological activities of the individual, the interdependence among cells making up the whole, and the correct positioning of cells within the larval body. This chapter examines physiological aspects of nutrient acquisition, digestion, assimilation, and distribution within invertebrate larvae from an organismic and comparative perspective. Growth and development of larvae obviously require the acquisition of “food.” Yet the mechanisms where particulate or dissolved organic materials are converted into biomass and promote development of larvae differ and are variably known among groups. Differences in the physiology of the digestive system (secreted enzymes, gut transit time, and assimilation) within and among feeding larvae suggest the possibility of an underappreciated plasticity of digestive physiology. How the ingestion of seawater by and the existence of a circulatory system within larvae contribute to larval growth and development represent important topics for future research.

An -omics Perspective on Marine Invertebrate Larvae

2018 ◽  
Keyword(s):  
Large Scale ◽  
Natural Variation ◽  
Molecular Mechanisms ◽  
Marine Invertebrate ◽  
Life History Evolution ◽  
Molecular Approaches ◽  
Fine Detail ◽  
Technological Advances ◽  
Gene Environment ◽  
Invertebrate Larvae

The diverse phenotypes exhibited by marine invertebrate larvae are the result of complex gene-environment interactions. Recently, technological advances in molecular biology have enabled large-scale -omics approaches, which can provide a global overview of the molecular mechanisms that shape the larval genotype-phenotype landscape. -omics approaches are facilitating our understanding of larval development and life history evolution, larval response to environmental stress, the larval microbiome, larval physiology and feeding, and larval behavior. These large-scale molecular approaches are even more effective when combined with large-scale environmental monitoring and phenotypic measurements. Current -omics approaches to studying larvae can be improved by the addition of functional genetic analyses and the reporting of natural variation in gene expression between individuals and populations. Systems-level approaches that combine multiple -omics techniques will allow us to explore in fine detail the interactions of environmental and genotypic influences on larval phenotype.

scholarly journals Molecular Mechanisms of Insulin Resistance in Polycystic Ovary Syndrome: Unraveling the Conundrum in Skeletal Muscle?

2019 ◽  
Vol 104 (11) ◽  
pp. 5372-5381 ◽  
Author(s):  
Nigel K Stepto ◽  
Alba Moreno-Asso ◽  
Luke C McIlvenna ◽  
Kirsty A Walters ◽  
Raymond J Rodgers
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Polycystic Ovary Syndrome ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Polycystic Ovary ◽  
Evidence Synthesis ◽  
Basic Research ◽  
Future Research ◽  
Ovary Syndrome

Abstract Context Polycystic ovary syndrome (PCOS) is a common endocrine condition affecting 8% to 13% of women across the lifespan. PCOS affects reproductive, metabolic, and mental health, generating a considerable health burden. Advances in treatment of women with PCOS has been hampered by evolving diagnostic criteria and poor recognition by clinicians. This has resulted in limited clinical and basic research. In this study, we provide insights into the current and future research on the metabolic features of PCOS, specifically as they relate to PCOS-specific insulin resistance (IR), that may affect the most metabolically active tissue, skeletal muscle. Current Knowledge PCOS is a highly heritable condition, yet it is phenotypically heterogeneous in both reproductive and metabolic features. Human studies thus far have not identified molecular mechanisms of PCOS-specific IR in skeletal muscle. However, recent research has provided new insights that implicate energy-sensing pathways regulated via epigenomic and resultant transcriptomic changes. Animal models, while in existence, have been underused in exploring molecular mechanisms of IR in PCOS and specifically in skeletal muscle. Future Directions Based on the latest evidence synthesis and technologies, researchers exploring molecular mechanisms of IR in PCOS, specifically in muscle, will likely need to generate new hypothesis to be tested in human and animal studies. Conclusion Investigations to elucidate the molecular mechanisms driving IR in PCOS are in their early stages, yet remarkable advances have been made in skeletal muscle. Overall, investigations have thus far created more questions than answers, which provide new opportunities to study complex endocrine conditions.

scholarly journals Immune function during pregnancy varies between ecologically distinct populations

2020 ◽  
Vol 2020 (1) ◽  
pp. 114-128
Author(s):  
Carmen Hové ◽  
Benjamin C Trumble ◽  
Amy S Anderson ◽  
Jonathan Stieglitz ◽  
Hillard Kaplan ◽  
...  
Keyword(s):  
Leukocyte Count ◽  
Total Leukocyte Count ◽  
Future Research ◽  
Differential Leukocyte Count ◽  
Ecological Conditions ◽  
Trade Offs ◽  
The Usa ◽  
Immunological Changes ◽  
Fetal Antigens ◽  
Pathogen Exposure

Abstract Background and objectives Among placental mammals, females undergo immunological shifts during pregnancy to accommodate the fetus (i.e. fetal tolerance). Fetal tolerance has primarily been characterized within post-industrial populations experiencing evolutionarily novel conditions (e.g. reduced pathogen exposure), which may shape maternal response to fetal antigens. This study investigates how ecological conditions affect maternal immune status during pregnancy by comparing the direction and magnitude of immunological changes associated with each trimester among the Tsimane (a subsistence population subjected to high pathogen load) and women in the USA. Methodology Data from the Tsimane Health and Life History Project (N = 935) and the National Health and Nutrition Examination Survey (N = 1395) were used to estimate population-specific effects of trimester on differential leukocyte count and C-reactive protein (CRP), a marker of systemic inflammation. Results In both populations, pregnancy was associated with increased neutrophil prevalence, reduced lymphocyte and eosinophil count and elevated CRP. Compared to their US counterparts, pregnant Tsimane women exhibited elevated lymphocyte and eosinophil counts, fewer neutrophils and monocytes and lower CRP. Total leukocyte count remained high and unchanged among pregnant Tsimane women while pregnant US women exhibited substantially elevated counts, resulting in overlapping leukocyte prevalence among all third-trimester individuals. Conclusions and implications Our findings indicate that ecological conditions shape non-pregnant immune baselines and the magnitude of immunological shifts during pregnancy via developmental constraints and current trade-offs. Future research should investigate how such flexibility impacts maternal health and disease susceptibility, particularly the degree to which chronic pathogen exposure might dampen inflammatory response to fetal antigens. Lay Summary This study compares immunological changes associated with pregnancy between the Tsimane (an Amazonian subsistence population) and individuals in the USA. Results suggest that while pregnancy enhances non-specific defenses and dampens both antigen-specific immunity and parasite/allergy response, ecological conditions strongly influence immune baselines and the magnitude of shifts during gestation.

scholarly journals A comprehensive review of the influences of nanoparticles as a fuel additive in an internal combustion engine (ICE)

2020 ◽  
Vol 9 (1) ◽  
pp. 1326-1349
Author(s):  
Siti Nurul Akmal Yusof ◽  
Nor Azwadi Che Sidik ◽  
Yutaka Asako ◽  
Wan Mohd. Arif Aziz Japar ◽  
Saiful Bahri Mohamed ◽  
...  
Keyword(s):  
Combustion Engine ◽  
Wide Spectrum ◽  
High Energy ◽  
Combustion Efficiency ◽  
Fuel Properties ◽  
Future Research ◽  
Biodiesel Fuel ◽  
Fuel Additive ◽  
Engine Combustion ◽  
Research Findings

Abstract Nanofluid is a colloidal mixture consisting of nano-sized particles dispersed in a liquid medium. It improves heat transfer properties and promotes high energy efficiency in a wide spectrum of engineering applications. In recent years, particularly in the automotive industry, the addition of nanofluid in diesel/biodiesel as an additive for ICE has become an attractive approach to promote enhanced combustion efficiency and emission reduction due to their superior thermophysical properties. Many researchers have previously demonstrated that the addition of nanoparticles in diesel/biodiesel fuel improved the overall engine combustion characteristics. As a whole, this study aims to summarize the recent research findings related to the effect of nanoparticles on the fuel properties and engine combustion efficiency. Furthermore, different types of additive blended with varying fuel properties are also compared and discussed. Lastly, the advantages and prospects of using nanofluid as an additive fuel are summarized for future research opportunities.

scholarly journals The Sex Determination Cascade in the Silkworm

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 315
Author(s):  
Xu Yang ◽  
Kai Chen ◽  
Yaohui Wang ◽  
Dehong Yang ◽  
Yongping Huang
Keyword(s):  
Sex Determination ◽  
Molecular Mechanisms ◽  
Future Research ◽  
Model Species ◽  
Male And Female ◽  
Master Regulators ◽  
Primary Signal ◽  
Basic Understanding ◽  
Female Specific ◽  
Working Mechanisms

In insects, sex determination pathways involve three levels of master regulators: primary signals, which determine the sex; executors, which control sex-specific differentiation of tissues and organs; and transducers, which link the primary signals to the executors. The primary signals differ widely among insect species. In Diptera alone, several unrelated primary sex determiners have been identified. However, the doublesex (dsx) gene is highly conserved as the executor component across multiple insect orders. The transducer level shows an intermediate level of conservation. In many, but not all examined insects, a key transducer role is performed by transformer (tra), which controls sex-specific splicing of dsx. In Lepidoptera, studies of sex determination have focused on the lepidopteran model species Bombyx mori (the silkworm). In B. mori, the primary signal of sex determination cascade starts from Fem, a female-specific PIWI-interacting RNA, and its targeting gene Masc, which is apparently specific to and conserved among Lepidoptera. Tra has not been found in Lepidoptera. Instead, the B. mori PSI protein binds directly to dsx pre-mRNA and regulates its alternative splicing to produce male- and female-specific transcripts. Despite this basic understanding of the molecular mechanisms underlying sex determination, the links among the primary signals, transducers and executors remain largely unknown in Lepidoptera. In this review, we focus on the latest findings regarding the functions and working mechanisms of genes involved in feminization and masculinization in Lepidoptera and discuss directions for future research of sex determination in the silkworm.

Navigating NGO–Government Relations in Human Rights: New Archival Evidence from Amnesty International, 1961–1986

2021 ◽  
Author(s):  
Swati Srivastava
Keyword(s):  
Human Rights ◽  
Oral History ◽  
Social History ◽  
Future Research ◽  
International Institute ◽  
Strategic Choices ◽  
Small Individual ◽  
Amnesty International ◽  
Government Relations ◽  
Trade Offs

Abstract This research note unveils new archival evidence from Amnesty International's first twenty-five years (1961–1986) to shed light on the realization of international human rights as Amnesty balanced “nonpolitical politics” through multifaceted government relations. The research draws from minutes and reports of eighty meetings of Amnesty's executive leadership and interviews from the 1983 to 1985 Amnesty Oral History project, all collected from the International Institute of Social History. The records show that during this time Amnesty relied on government and foundation funding to exit a severe financial crisis. Amnesty also cultivated a private diplomatic network with governments for access and advocacy and conducted side bargains with closed countries for access and reforms. In one sense, the new evidence complicates the conventional wisdom that Amnesty was only financed from small, individual donors and stayed away from private government dealings. In another sense, the new data extend existing insights about INGO strategic action by revealing Amnesty's pragmatic trade-offs when maintaining arms–length relations with governments to better appreciate the organization's early challenges and accomplishments. The note ultimately contributes to scholarship on the strategic choices of INGOs and provides new data for future research on the agency of nonstate actors in global governance navigating complex government relations. Esta nota de investigación presenta nueva evidencia documental de los primeros 25 años de Amnistía Internacional (Amnesty International), de 1961 a 1986, para arrojar luz sobre el cumplimiento de las normas internacionales de derechos humanos mientras Amnistía balanceaba la “política no política” mediante relaciones gubernamentales polifacéticas. La investigación incorpora actas e informes de 80 reuniones del liderazgo ejecutivo de Amnistía y entrevistas de 1983 a 1985 del proyecto Historia Oral de Amnistía (Amnesty Oral History), recopiladas del Instituto Internacional de Historia Social. Los documentos muestran que, en ese momento, Amnistía necesitó financiación gubernamental y de fundaciones para salir de una crisis financiera grave. Amnistía también cultivó una red diplomática privada con gobiernos a cambio de acceso y defensa, y tuvo negocios paralelos con países cerrados a cambio de acceso y reformas. En un sentido, la nueva evidencia complica la sabiduría convencional de que Amnistía solo tuvo financiamiento de donantes pequeños e individuos y se mantuvo lejos de los negocios privados con gobiernos. En contraste, los nuevos datos amplían las percepciones existentes sobre la acción estratégica de organizaciones no gubernamentales internacionales (ONGI), revelando las concesiones pragmáticas de Amnistía al mantener relaciones independientes con gobiernos, y permiten apreciar mejor los desafíos y logros iniciales de la organización. La nota, fundamentalmente, contribuye a la investigación sobre las decisiones estratégicas de las ONGI y brinda nuevos datos para futuras investigaciones sobre la autonomía de los actores no estatales que navegan relaciones gubernamentales complejas en la gobernanza global. Cet exposé de recherche dévoile de nouvelles preuves issues des 25 premières années d'archives d'Amnesty International (1961–1986) pour apporter un éclairage sur l'application des droits de l'Homme tandis qu'Amnesty équilibrait la « politique apolitique » par le biais de relations gouvernementales à plusieurs facettes. Cette recherche s'appuie sur des minutes et rapports de 80 réunions de la haute direction d'Amnesty, ainsi que sur des entretiens qui ont eu lieu entre 1983 et 1985 dans le cadre du projet Oral History (Histoire orale) d'Amnesty. Ces données ont toutes été recueillies auprès de l'Institut International d'Histoire Sociale. Les archives montrent que durant cette période, Amnesty a dû compter sur le financement de gouvernements et de fondations pour sortir d'une grave crise financière. Amnesty a également cultivé un réseau diplomatique privé avec des gouvernements pour faciliter son accès et son plaidoyer dans le pays concerné tout en menant des négociations parallèles avec les pays fermés pour y favoriser son accès et les réformes. En un sens, les nouvelles preuves compliquent les idées reçues selon lesquelles Amnesty ne serait financée que par de petits donateurs individuels et resterait à l’écart des affaires gouvernementales privées. Mais en un autre sens, ces nouvelles données enrichissent les renseignements existants sur l'action stratégique des organisations non gouvernementales internationales en révélant qu'Amnesty s’était livrée à des compromis pragmatiques en entretenant des relations avec les gouvernements tout en restant à distance. Ces renseignements nous permettent donc de mieux apprécier les premiers défis et accomplissements de l'organisation. En définitive, cet exposé contribue aux études sur les choix stratégiques des organisations non gouvernementales internationales et fournit de nouvelles données pour les recherches futures sur l'intervention des acteurs non étatiques dans la gouvernance mondiale tandis qu'ils naviguent dans des relations gouvernementales complexes.

scholarly journals Recent Advances in Nanotechnology with Nano-Phytochemicals: Molecular Mechanisms and Clinical Implications in Cancer Progression

2021 ◽  
Vol 22 (7) ◽  
pp. 3571
Author(s):  
Bonglee Kim ◽  
Ji-Eon Park ◽  
Eunji Im ◽  
Yongmin Cho ◽  
Jinjoo Lee ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Animal Studies ◽  
Molecular Mechanisms ◽  
Future Research ◽  
Clinical Implications ◽  
Research Perspectives ◽  
Current Review ◽  
Gold Silver ◽  
Significant Efficacy ◽  
Rapid Clearance

Biocompatible nanoparticles (NPs) containing polymers, lipids (liposomes and micelles), dendrimers, ferritin, carbon nanotubes, quantum dots, ceramic, magnetic materials, and gold/silver have contributed to imaging diagnosis and targeted cancer therapy. However, only some NP drugs, including Doxil® (liposome-encapsulated doxorubicin), Abraxane® (albumin-bound paclitaxel), and Oncaspar® (PEG-Asparaginase), have emerged on the pharmaceutical market to date. By contrast, several phytochemicals that were found to be effective in cultured cancer cells and animal studies have not shown significant efficacy in humans due to poor bioavailability and absorption, rapid clearance, resistance, and toxicity. Research to overcome these drawbacks by using phytochemical NPs remains in the early stages of clinical translation. Thus, in the current review, we discuss the progress in nanotechnology, research milestones, the molecular mechanisms of phytochemicals encapsulated in NPs, and clinical implications. Several challenges that must be overcome and future research perspectives are also described.

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