Search results for: Marcela Nouzova

Items from 1 to 18 out of 18 results

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Fast, ultra-trace detection of juvenile hormone III from mosquitoes using mass spectrometry

Cesar E. Ramirez, Marcela Nouzova, Paolo Benigni, J. Martin E. Quirke, more

Talanta > 2016 > 159 > C > 371-378

In the present work, a new protocol for fast separation and quantification of JH III from biological samples using liquid chromatography coupled to electrospray tandem mass spectrometry is described. In particular, the proposed protocol improves existing methodologies by combining a limited number of sample preparation steps with fast LC-MS/MS detection, providing lower limits of detection and demonstrated...

article

20-hydroxyecdysone stimulation of juvenile hormone biosynthesis by the mosquito corpora allata

Maria Areiza, Marcela Nouzova, Crisalejandra Rivera-Perez, Fernando G. Noriega

Insect Biochemistry and Molecular Biology > 2015 > 64 > Complete > 100-105

Juvenile hormone III (JH) is synthesized by the corpora allata (CA) and plays a key role in mosquito development and reproduction. JH titer decreases in the last instar larvae allowing pupation and metamorphosis to progress. As the anti-metamorphic role of JH comes to an end, the CA of the late pupa (or pharate adult) becomes again “competent” to synthesize JH, which plays an essential role orchestrating...

article

Allatostatin-C reversibly blocks the transport of citrate out of the mitochondria and inhibits juvenile hormone synthesis in mosquitoes

Marcela Nouzova, Crisalejandra Rivera-Perez, Fernando G. Noriega

Insect Biochemistry and Molecular Biology > 2015 > 57 > Complete > 20-26

Aedes aegypti allatostatin-C (AeaAST-C or PISCF-AST) is a strong and fast reversible inhibitor of juvenile hormone III (JH III) synthesis by the corpora allata (CA) of mosquitoes; however, its mechanism of action remains poorly understood. AeaAST-C showed no inhibitory activity in the presence of any of the intermediate precursors of JH III indicating that the AeaAST-C target is located before the...

article

Coordinated changes in JH biosynthesis and JH hemolymph titers in Aedes aegypti mosquitoes

Salvador Hernández-Martínez, Crisalejandra Rivera-Perez, Marcela Nouzova, Fernando G. Noriega

Journal of Insect Physiology > 2015 > 72 > Complete > 22-27

Juvenile hormone III (JH) is synthesized by the corpora allata (CA) and plays a key role in mosquito development and reproduction. A decrease in JH titer during the last instar larvae allows pupation and metamorphosis to proceed. As the anti-metamorphic role of JH comes to an end, the CA of the late pupa once again synthesizes JH, which plays an essential role in orchestrating reproductive maturation...

article

Ecdysis triggering hormone ensures proper timing of juvenile hormone biosynthesis in pharate adult mosquitoes

Maria Areiza, Marcela Nouzova, Crisalejandra Rivera-Perez, Fernando G. Noriega

Insect Biochemistry and Molecular Biology > 2014 > 54 > Complete > 98-105

Juvenile hormones (JHs) are synthesized by the corpora allata (CA) and play a key role in insect development. A decrease of JH titer in the last instar larvae allows pupation and metamorphosis to proceed. As the anti-metamorphic role of JH comes to an end, the CA of the late pupa (or pharate adult) becomes again “competent” to synthesize JH, which would play an essential role orchestrating reproductive...

article

Metabolic analysis reveals changes in the mevalonate and juvenile hormone synthesis pathways linked to the mosquito reproductive physiology

Crisalejandra Rivera-Perez, Marcela Nouzova, Ivanna Lamboglia, Fernando G. Noriega

Insect Biochemistry and Molecular Biology > 2014 > 51 > Complete > 1-9

Juvenile hormone (JH) regulates reproductive maturation in insects; therefore interruption of JH biosynthesis has been considered as a strategy for the development of target-specific insecticides. The corpora allata (CA) from mosquitoes is highly specialized to supply variable levels of JH, which are linked to ovarian developmental stages and influenced by nutritional signals. However, very little...

article

Male Aedes aegypti mosquitoes use JH III transferred during copulation to influence previtellogenic ovary physiology and affect the reproductive output of female mosquitoes

Mark E. Clifton, Stefano Correa, Crisalejandra Rivera-Perez, Marcela Nouzova, more

Journal of Insect Physiology > 2014 > 64 > Complete > 40-47

The effect of male accessory gland substances on female reproductive physiology has been previously described as “activating” egg development. However, no mechanism has been described that can explain how male mosquitoes are able to influence egg development in female mosquitoes. To investigate how male mosquitoes are able to influence ovarian physiology and reproductive output we explored three main...

article

Aldehyde dehydrogenase 3 converts farnesal into farnesoic acid in the corpora allata of mosquitoes

Crisalejandra Rivera-Perez, Marcela Nouzova, Mark. E. Clifton, Elena Martin Garcia, more

Insect Biochemistry and Molecular Biology > 2013 > 43 > 8 > 675-682

The juvenile hormones (JHs) play a central role in insect reproduction, development and behavior. Interrupting JH biosynthesis has long been considered a promising strategy for the development of target-specific insecticides. Using a combination of RNAi, in vivo and in vitro studies we characterized the last unknown biosynthetic enzyme of the JH pathway, a fatty aldehyde dehydrogenase (AaALDH3) that...

article

FUNCTIONAL ANALYSIS OF A MOSQUITO SHORT‐CHAIN DEHYDROGENASE CLUSTER

Jaime G. Mayoral, Kate T. Leonard, Marcela Nouzova, Fernando G. Noriega, more

Archives of Insect Biochemistry and Physiology > 82 > 2 > 96 - 115

The short‐chain dehydrogenases (SDR) constitute one of the oldest and largest families of enzymes with over 46,000 members in sequence databases. About 25% of all known dehydrogenases belong to the SDR family. SDR enzymes have critical roles in lipid, amino acid, carbohydrate, hormone, and xenobiotic metabolism as well as in redox sensor mechanisms. This family is present in archaea, bacteria, and eukaryota, emphasizing their versatility and fundamental importance for metabolic processes. We identified a cluster of eight SDRs in the mosquito Aedes aegypti (AaSDRs). Members of the cluster differ in tissue specificity and developmental expression. Heterologous expression produced recombinant proteins that had diverse substrate specificities, but distinct from the conventional insect alcohol (ethanol) dehydrogenases. They are all NADP...

article

Characterization of an isopentenyl diphosphate isomerase involved in the juvenile hormone pathway in Aedes aegypti

Miguel E. Diaz, Jaime G. Mayoral, Horacio Priestap, Marcela Nouzova, more

Insect Biochemistry and Molecular Biology > 2012 > 42 > 10 > 751-757

Isopentenyl diphosphate isomerase (IPPI) is an enzyme involved in the synthesis of juvenile hormone (JH) in the corpora allata (CA) of insects. IPPI catalyzes the conversion of isopentenyl pyrophosphate (IPP) to dimethylallyl pyrophosphate (DMAPP); afterward IPP and DMAPP condense in a head-to-tail manner to produce geranyl diphosphate (GPP), this head-to-tail condensation can be repeated, by the...

article

Functional characterization of an allatotropin receptor expressed in the corpora allata of mosquitoes

Marcela Nouzova, Anne Brockhoff, Jaime G. Mayoral, Marianne Goodwin, more

Peptides > 2012 > 34 > 1 > 201-208

Allatotropin is an insect neuropeptide with pleiotropic actions on a variety of different tissues. In the present work we describe the identification, cloning and functional and molecular characterization of an Aedes aegypti allatotropin receptor (AeATr) and provide a detailed quantitative study of the expression of the AeATr gene in the adult mosquito. Analysis of the tissue distribution of AeATr...

article

A coordinated expression of biosynthetic enzymes controls the flux of juvenile hormone precursors in the corpora allata of mosquitoes

Marcela Nouzova, Marten J. Edwards, Jaime G. Mayoral, Fernando G. Noriega

Insect Biochemistry and Molecular Biology > 2011 > 41 > 9 > 660-669

Juvenile hormone (JH) is a key regulator of metamorphosis and ovarian development in mosquitoes. Adult female Aedes aegypti mosquitoes show developmental and dynamically regulated changes of JH synthesis. Newly emerged females have corpora allata (CA) with low biosynthetic activity, but they produce high amounts of JH a day later; blood feeding results in a striking decrease in JH synthesis, but the...

article

Allatostatin-C receptors in mosquitoes

Jaime G. Mayoral, Marcela Nouzova, Anne Brockhoff, Marianne Goodwin, more

Peptides > 2010 > 31 > 3 > 442-450

In the present work we describe the functional and molecular characterization of two Aedes aegypti allatostatin-C receptor paralogs (AeAS-CrA and AeAS-CrB) and provide a detailed quantitative study of the expression of the AS-C receptor genes in an adult insect. The tissue distribution of the two AS-C receptors differed significantly; the mRNA levels of AeAS-CrB in the Malpighian tubules were the...

article

Rapid direct analysis in real time (DART) mass spectrometric detection of juvenile hormone III and its terpene precursors

Arti T. Navare, Jaime G. Mayoral, Marcela Nouzova, Fernando G. Noriega, more

Analytical and Bioanalytical Chemistry > 2010 > 398 > 7-8 > 3005-3013

Direct analysis in real time (DART) is a plasma-based ambient ionization technique that enables rapid ionization of small molecules with high sample throughput. In this work, DART was coupled to an orthogonal (oa) time-of-flight (TOF) mass spectrometer and the system was optimized for analyzing a vital hormonal regulator in insects, juvenile hormone (JH) III and its terpene precursors, namely, farnesol,...

article

Molecular and functional characterization of a juvenile hormone acid methyltransferase expressed in the corpora allata of mosquitoes

Jaime G. Mayoral, Marcela Nouzova, Michiyo Yoshiyama, Tetsuro Shinoda, more

Insect Biochemistry and Molecular Biology > 2009 > 39 > 1 > 31-37

A juvenile hormone acid methyltransferase (JHAMT) was isolated as an abundant EST in a library of the corpora allata of the adult female mosquito Aedes aegypti. Its full length cDNA encodes a 278-aa protein that has 43% amino acid identity with BmJHAMT, a juvenile hormone acid methyltransferase previously cloned from Bombyx mori. Heterologous expression produced a recombinant protein that metabolizes...

article

Chromosome Transfer Activates and Delineates a Locus Control Region for Perforin

Matthew E. Pipkin, Belma Ljutic, Fernando Cruz-Guilloty, Marcela Nouzova, more

Immunity > 2007 > 26 > 1 > 29-41

Perforin gene (PRF1) transcription regulates perforin expression in NK cells and CTL. Here we identified the locus-wide ensemble of cis-acting sequences that drives PRF1 transcription physiologically. By using chromosome transfer, we revealed that de novo activation of a silent PRF1 locus was controlled by a 150 kb domain comprised of 16 DNase I hypersensitive sites (DHSs). These cis-acting sequences...

article

Microarray-based survey of repetitive genomic sequences in Vicia spp.

Marcela Nouzová, Pavel Neumann, Alice Navrátilová, David W. Galbraith, more

Plant Molecular Biology > 2001 > 45 > 2 > 229-244

A modified DNA microarray-based technique was devised for preliminary screening of short fragment genomic DNA libraries from three Vicia species (V. melanops, V. narbonensis, and V. sativa) to isolate representative highly abundant DNA sequences that show different distribution patterns among related legume species. The microarrays were sequentially hybridized with labeled genomic DNAs of thirteen...

article

Cloning and Characterization of New Repetitive Sequences in Field Bean (Vicia fabaL.)

MARCELA NOUZOVÁ, MARIE KUBALÁKOVÁ, MARIE DOLEŽELOVÁ, ANDREA KOBLÍŽKOVÁ, more

Annals of Botany > 1999 > 83 > 5 > 535-541

Five new repetitive sequences have been isolated from theVicia fabagenome, by cloning bands visible on agarose gel electrophoresis after digestion of genomic DNA with various restriction enzymes. The sequences were 109 to 584 bp long, their abundance ranging from 5×10 ⁴ to 5×10 ⁵ copies per haploid genome. Southern blot andin situhybridization revealed that four of five newly isolated...

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