Publications by authors named "Sheila Ons"

Article Synopsis
  • Dengue outbreaks in Buenos Aires Province are increasing due to the Aedes aegypti mosquito's colonization and widespread pyrethroid insecticide use for control.
  • A study identified the kdr mutations associated with pyrethroid resistance in mosquitoes, documenting the 1016Ikdr + 1534Ckdr and the V410L mutations for the first time in central Argentina.
  • The findings highlight the need for effective resistance management strategies and improved diagnostics to tackle the growing pyrethroid resistance in dengue vectors.
View Article and Find Full Text PDF
Article Synopsis
  • Obligate blood-feeding insects, like the kissing bug Rhodnius prolixus, use their internal taste sensilla in the pharynx to assess the quality of the blood they ingest for survival.
  • The study identified eight taste sensilla in the pharyngeal organ, which contain neurons that respond to various gustatory stimuli such as salt and caffeine, indicating their role in detecting food quality.
  • RNA sequencing revealed several sensory-related gene families in the pharyngeal organ, and RNA interference studies indicated that specific channels are necessary for processing the preferred feeding solutions.
View Article and Find Full Text PDF

Molecular diagnostic methods to detect and quantify viral RNA in clinical samples rely on the purification of the genetic material prior to reverse transcription polymerase chain reaction (qRT-PCR). Due to the large number of samples processed in clinical laboratories, automation has become a necessity in order to increase method processivity and maximize throughput per unit of time. An attractive option for isolating viral RNA is based on the magnetic solid phase separation procedure (MSPS) using magnetic microparticles.

View Article and Find Full Text PDF

Background: The mosquito Aedes aegypti is an urban vector of dengue and other arboviruses. During epidemics of these viruses, pyrethroid insecticides are used for the control of adult mosquitoes. The worldwide resistance of Ae.

View Article and Find Full Text PDF
Article Synopsis
  • Blood-feeding in triatomines triggers key physiological changes like development and reproduction, influenced by their specific feeding habits.
  • The gut of these blood-sucking insects must adapt post-feeding due to the varying quality and quantity of blood, with gene expression regulation playing a crucial role.
  • Silencing the gene eIF3m in Rhodnius prolixus revealed significant impacts on digestion, growth, and reproduction, highlighting its unique function in these insects compared to what is known in Drosophila melanogaster.
View Article and Find Full Text PDF

Background: Hemiptera is one of the most speciose orders of insects, and the most speciose considering Hemimetabola. Through their evolutive history, hemipterans with different feeding habits have adapted to deal with different chemical challenges. Three major gene families are involved in xenobiotic detoxification in insects: the cytochromes P450 (CYPs), carboxyl/cholinesterases (CCEs), and glutathione transferases (GSTs).

View Article and Find Full Text PDF
Article Synopsis
  • In ecdysozoan animals, the process of moulting, which involves shedding and forming a new exoskeleton, is triggered by the hormone ecdysone and a complex signaling cascade involving neuropeptides.
  • This study focuses on the insect Rhodnius prolixus to explore if the neuropeptide mechanisms for ecdysis found in Holometabola (complete metamorphosis) are also present in Hemimetabola (incomplete metamorphosis), while also examining their role in female reproduction.
  • Results show that reducing specific hormones like ecdysis triggering hormone (ETH) affects nymph survival and egg hatching but doesn't change oviposition,
View Article and Find Full Text PDF

Background: Triatoma infestans is the main vector of Chagas disease in the Southern Cone. The resistance to pyrethroid insecticides developed by populations of this species impairs the effectiveness of vector control campaigns in wide regions of Argentina. The study of the global transcriptomic response to pyrethroid insecticides is important to deepen the knowledge about detoxification in triatomines.

View Article and Find Full Text PDF

In animals, neuropeptidergic signaling is essential for the regulation of survival and reproduction. In insects, Orcokinins are poorly studied, despite their high level of conservation among different orders. In particular, there are currently no reports on the role of Orcokinins in the experimental insect model, the fruit fly, Drosophila melanogaster.

View Article and Find Full Text PDF
Article Synopsis
  • Aedes aegypti, a mosquito that transmits serious diseases, has developed resistance to synthetic insecticides, making alternative control methods necessary.
  • This study uses RNA-Seq to analyze gene expression in Aedes aegypti larvae after exposure to Eucalyptus camaldulensis essential oil, revealing genes related to detoxification and chemosensory responses.
  • The findings highlight the potential of Eucalyptus-derived compounds in mosquito control by identifying gene families involved in detoxification, which could enhance the effectiveness of natural larvicides in managing mosquito populations.
View Article and Find Full Text PDF

The use of chemical insecticides is the main control method for Blattella germanica worldwide. The prolonged and frequent use of insecticides produced the selection of insecticide-resistant individuals. The German cockroach is one of the most widespread urban pests in Argentina.

View Article and Find Full Text PDF

Rhodnius prolixus is a blood-feeding insect vector of Trypanosoma cruzi, a protozoan parasite that causes Chagas disease. During each blood meal, the animals ingest large volumes of blood, that may be up to 12 times the unfed body mass. These blood meals impose a significant osmotic stress for the animals due to the hyposmotic condition of the ingested blood compared with the insect's hemolymph.

View Article and Find Full Text PDF

The southern green stink bug, Nezara viridula is one of the primary soybean pests and causes significant economic losses around the world. In spite of the high proteases inhibitor (PI) levels, N. viridula can feed on developing seeds of field-grown soybean and reduce crop yields.

View Article and Find Full Text PDF

The Indian meal moth Plodia interpunctella is a pest of stored products worldwide. Plant-derived essential oils with insecticidal activity could be safe products to control this species. The scarce information about the mode of action of most plant-derived products limits their use for the control of insect pests.

View Article and Find Full Text PDF

The honey bee Apis mellifera is the most abundant managed pollinator in diverse crops worldwide. Consequently, it is exposed to a plethora of environmental stressors, among which are the agrochemicals. In agroecosystems, the herbicide glyphosate (GLY) is one of the most applied.

View Article and Find Full Text PDF

Background: Rhodnius prolixus has become a model for revealing the molecular bases of insect sensory biology due to the publication of its genome and its well-characterized behavioural repertoire. Gene expression modulation underlies behaviour-triggering processes at peripheral and central levels. Still, the regulation of sensory-related gene transcription in sensory organs is poorly understood.

View Article and Find Full Text PDF

Given that hematophagous insects ingest large quantities of blood in a single meal, they must undergo a rapid post-prandial diuresis in order to maintain homeostasis. In the kissing bug (Hemiptera: Reduviidae), the coordinated activity of the Malpighian tubules and anterior midgut maintains water and ion balance during the post-prandial diuresis. Three to four hours after the meal, the diuretic process finishes, and the animal enters an antidiuretic state to ensure water conservation until the next blood intake.

View Article and Find Full Text PDF

Cuticle tanning occurs in insects immediately after hatching or molting. During this process, the cuticle becomes dark and rigid due to melanin deposition and protein crosslinking. In insects, different from mammals, melanin is synthesized mainly from dopamine, which is produced from DOPA by the enzyme DOPA decarboxylase.

View Article and Find Full Text PDF

Stinkbugs (Hemiptera: Pentatomidae) are of major economic importance as pest of crops. Among the species composing the stinkbug complex, Nezara viridula is one of the most abundant in Brazil, Argentina and the Southern USA. However, this species has been poorly characterized at the genetic and physiological level.

View Article and Find Full Text PDF

Ecdysis is a vital process for insects, during which they shed the old cuticle in order to emerge as the following developmental stage. Given its relevance for survival and reproduction, ecdysis is tightly regulated by peptidic hormones that conform an interrelated neuromodulatory network. This network was studied in species that undergo a complete metamorphosis, but not in hemimetabola.

View Article and Find Full Text PDF

Allatotropins (AT) are neuropeptides with pleotropic functions on a variety of insect tissues. They affect processes such as juvenile hormone biosynthesis, cardiac rhythm, oviduct and hindgut contractions, nutrient absorption and circadian cycle. The present work provides experimental evidence that AT elicits immune responses in two important mosquito disease vectors, Anopheles albimanus and Aedes aegypti.

View Article and Find Full Text PDF

Background: Triatomine insects are vectors of Trypanosoma cruzi, a protozoan parasite that is the causative agent of Chagas' disease. This is a neglected disease affecting approximately 8 million people in Latin America. The existence of diverse pyrethroid resistant populations of at least two species demonstrates the potential of triatomines to develop high levels of insecticide resistance.

View Article and Find Full Text PDF

To grow and develop insects must undergo ecdysis. During this process, the individual sheds the old cuticle to emerge as the following developmental stage. During ecdysis, different programed behaviors are regulated by neuropeptidergic pathways.

View Article and Find Full Text PDF

Chagas' disease, affecting up to 6-7 million people worldwide, is transmitted to humans through the feces of triatomine kissing bugs. From these, Rhodnius prolixus, Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis are important vectors distributed throughout the Latin American subcontinent. Resistance to pyrethroids has been developed by some triatomine populations, especially T.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionq1l5q9rq0nal1bgn6ej8s4kbk2ttlnm8): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once