Publications by authors named "Helga Gomes"

Aurora kinases (AURK) play a central role in controlling cell cycle in a wide range of organisms. They belong to the family of serine-threonine kinase proteins. Their role in the cell cycle includes, among others, the entry into mitosis, maturation of the centrosome and formation of the mitotic spindle.

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The mixoplankton green Noctiluca scintillans (gNoctiluca) is known to form extensive green tides in tropical coastal ecosystems prone to eutrophication. In the Arabian Sea, their recent appearance and annual recurrence have upended an ecosystem that was once exclusively dominated by diatoms. Despite evidence of strong links to eutrophication, hypoxia and warming, the mechanisms underlying outbreaks of this mixoplanktonic dinoflagellate remain uncertain.

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The mosquito Aedes aegypti undertakes a shift in carbohydrate metabolism during embryogenesis, including an increase in the activity of phosphoenolpyruvate carboxykinase (PEPCK), a key gluconeogenic enzyme, at critical steps of embryo development. All eukaryotes studied to date present two PEPCK isoforms, namely PEPCK-M (mitochondrial) and PEPCK-C (cytosolic). In A.

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DNA topoisomerase II enzymes maintain DNA stability during vital processes, such as genome replication, transcription and chromosomal segregation during mitosis and meiosis. In the present work, we analyzed functional aspects of the DNA topoisomerase II (AeTopII) enzyme of the mosquito Aedes aegypti. Here, we show that AeTopII mRNA is expressed at all stages of mosquito development.

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To further obtain insights into the Rhipicephalus microplus transcriptome, we used RNA-seq to carry out a study of expression in (i) embryos; (ii) ovaries from partially and fully engorged females; (iii) salivary glands from partially engorged females; (iv) fat body from partially and fully engorged females; and (v) digestive cells from partially, and (vi) fully engorged females. We obtained > 500 million Illumina reads which were assembled de novo, producing > 190,000 contigs, identifying 18,857 coding sequences (CDS). Reads from each library were mapped back into the assembled transcriptome giving a view of gene expression in different tissues.

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This study aimed to evaluate the effect of regulating phosphatidylinositol 3-kinase (PI3K) activity on the kinetics of oocyte nuclear maturation and the blastocyst rate. To evaluate oocyte viability, nuclear maturation rate and in vitro embryo production, cumulus-oocyte complexes (COCs) were maintained for 0, 10 min, 6 h or 22 h in TCM 199 medium supplemented with 20 nM wortmannin, an inhibitor of PI3K. After each period, COCs were transferred to the same medium without wortmannin and kept under the same conditions until completion of 22 h of in vitro maturation (IVM).

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The recent trend of global warming has exerted a disproportionately strong influence on the Eurasian land surface, causing a steady decline in snow cover extent over the Himalayan-Tibetan Plateau region. Here we show that this loss of snow is undermining winter convective mixing and causing stratification of the upper layer of the Arabian Sea at a much faster rate than predicted by global climate models. Over the past four decades, the Arabian Sea has also experienced a profound loss of inorganic nitrate.

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The blooms of Noctiluca in the Gulf of Oman and the Arabian Sea have been intensifying in recent years, posing now a threat to regional fisheries and the long-term health of an ecosystem supporting a coastal population of nearly 120 million people. We present the results of a local-scale data analysis to investigate the onset and patterns of the Noctiluca blooms, which form annually during the winter monsoon in the Gulf of Oman and in the Arabian Sea. Our approach combines methods in physical and biological oceanography with machine learning techniques.

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Roundup® is currently the most widely used and sold agricultural pesticide in the world. The objective of this work was to investigate the effects of Roundup® on energy metabolism during zebrafish (Danio rerio) embryogenesis. The embryo toxicity test was performed for 96 h post-fertilisation and the sublethal concentration of Roundup® was defined as 58.

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The cattle tick R. microplus is the biggest obstacle to livestock rearing in tropical countries. It is responsible for billions of dollars in losses every year, affecting meat and milk production, beef and dairy cattle, and the leather industry.

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The cattle tick is one of the most important ectoparasites causing significant economic losses for the cattle industry. The major tool of control is reducing the number of ticks, applying acaricides in cattle. However, overuse has led to selection of resistant populations of to most of these products, some even to more than one active principle.

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The Amazon River has the largest discharge of all rivers on Earth, and its complex plume system fuels a wide array of biogeochemical processes, across a large area of the western tropical North Atlantic. The plume thus stimulates microbial processes affecting carbon sequestration and nutrient cycles at a global scale. Chromosomal gene expression patterns of the 2.

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The Costa Rica Dome (CRD) is a unique open-ocean upwelling system, with picophytoplankton dominance of phytoplankton biomass and suppressed diatoms, yet paradoxically high export of biogenic silica. As a part of Flux and Zinc Experiments cruise in summer (June-July 2010), we conducted shipboard incubation experiments in the CRD to examine the potential roles of Si, Zn, Fe and light as regulating factors of phytoplankton biomass and community structure. Estimates of photosynthetic quantum yields revealed an extremely stressed phytoplankton population that responded positively to additions of silicic acid, iron and zinc and higher light conditions.

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Article Synopsis
  • Ticks are major carriers of animal diseases and rank just below mosquitoes for spreading human pathogens.
  • Researchers investigated cyclin-dependent kinases (CDKs), which regulate the cell cycle in organisms, as potential targets for anti-tick vaccines.
  • Immunization with a specific CDK from the tick species Ixodes persulcatus led to significant reductions in tick feeding and reproduction, suggesting that targeting CDKs could enhance the effectiveness of anti-tick vaccines.
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In this work we evaluated several genes involved in gluconeogenesis, glycolysis and glycogen metabolism, the major pathways for carbohydrate catabolism and anabolism, in the BME26 Rhipicephalus microplus embryonic cell line. Genetic and catalytic control of the genes and enzymes associated with these pathways are modulated by alterations in energy resource availability (primarily glucose). BME26 cells in media were investigated using three different glucose concentrations, and changes in the transcription levels of target genes in response to carbohydrate utilization were assessed.

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Article Synopsis
  • CDKs are crucial for cell cycle progression and have been identified in Rhipicephalus microplus, the southern cattle tick, through analysis of a transcriptome database.
  • Both CDK1 and CDK10 from this tick species possess caspase-3/7 cleavage motifs, which are essential for their function, although they differ in motif position and protein length.
  • Inhibition assays with Roscovitine showed that it decreases cell viability in the R. microplus BME26 cell line, indicating that CDKs could be promising targets for developing new treatments against tick infestations.
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Control of energy metabolism is an essential process for life. In insects, egg formation (oogenesis) and embryogenesis is dependent on stored molecules deposited by the mother or transcribed later by the zygote. In oviparous insects the egg becomes an isolated system after egg laying with all energy conversion taking place during embryogenesis.

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The recent trend of declining winter and spring snow cover over Eurasia is causing a land-ocean thermal gradient that is particularly favorable to stronger southwest (summer) monsoon winds. Since 1997, sea surface winds have been strengthening over the western Arabian Sea. This escalation in the intensity of summer monsoon winds, accompanied by enhanced upwelling and an increase of more than 350% in average summertime phytoplankton biomass along the coast and over 300% offshore, raises the possibility that the current warming trend of the Eurasian landmass is making the Arabian Sea more productive.

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