The mitotic metaphases of five Andean species of genus Drosophila are described for the first tim... more The mitotic metaphases of five Andean species of genus Drosophila are described for the first time. The evolutionary and interspecific genetic relationships within three Neotropical Drosophila species groups are analyzed. The diploid chromosome number for each species is as follows:
Revista Ecuatoriana de Medicina y Ciencias Biológicas (REMCB), May 6, 2022
Resumen.-Este trabajo recopila información sobre la expresión de los genes y proteínas de choque ... more Resumen.-Este trabajo recopila información sobre la expresión de los genes y proteínas de choque térmico en respuesta a los cambios de temperatura. Está enfocado en las especies más representativas de los órdenes de insectos más estudiados, a través de las cuales se compara la variación de la expresión de los genes Hsp y proteínas Hsp entre los órdenes y poblaciones de insectos y se expone su posible vínculo con la adaptación ambiental.
Drosophila melanogaster hemolymph cells are confirmed as a model to study the activation of immun... more Drosophila melanogaster hemolymph cells are confirmed as a model to study the activation of immune system due to foreign stimuli like iron nanoparticles. The toxicity of nanoparticles is a cause for concern due to their effect on human health and the environment. The aim of this study was to detect the activation of cellular immune response in Drosophila larvae through the observation of hemolymph composition, DNA damage and larval viability, after the exposure to 500 ppm and 1000 ppm chitosan-coated magnetite nanoparticles for 24 hours. Our results showed activation of cellular immune response after exposure to the nanoparticles owing to the increment of hemocytes, the emergence of lamellocytes and the presence of apoptotic hemocytes. In addition, chitosan-coated magnetite nanoparticles produce DNA damage detected by comet assay as well as low viability of larvae. No DNA damage is showed at 500 ppm. The cellular toxicity is directly associated with 1000 ppm.
Nanoparticles are a cause for concern because of their potential toxic effects on human health an... more Nanoparticles are a cause for concern because of their potential toxic effects on human health and the environment. The aim of this study was to assess the toxic effect of chitosan-coated magnetite nanoparticles (11.00±4.7 nm) on Drosophila melanogaster through the observation of hemolymph composition, DNA damage, larval survival and lifespan of flies. Chitosan-coated magnetite nanoparticles were synthesized by coprecipitation method. Drosophila larvaes and adults were exposed to 500 and 1000 ppm nanoparticles solution. After exposure, each type of larval hemocytes was recognized. Comet assay was performed to detect the DNA damage in the hemocytes. Also, the larval survival and lifespan of exposed flies were observed. Our results showed the toxic effect of the chitosan-coated magnetite nanoparticles through the increment of hemocytes, the emergence of lamellocytes, the presence of apoptotic hemocytes and the DNA damage detected by comet assay. In addition, nanoparticles produce decreasing of larval survival and shortening of the mean and maximum lifespan. The toxic effect the chitosan-coated magnetite nanoparticles is directly associated with 1000 ppm. No DNA damage was observed at 500 ppm.
Revista Ecuatoriana de Medicina y Ciencias Biológicas
Este trabajo recopila información sobre la expresión de los genes y proteínas de choque térmico e... more Este trabajo recopila información sobre la expresión de los genes y proteínas de choque térmico en respuesta a los cambios de temperatura. Está enfocado en las especies más representativas de los órdenes de insectos más estudiados, a través de las cuales se compara la variación de la expresión de los genes Hsp y proteínas Hsp entre los órdenes y poblaciones de insectos y se expone su posible vínculo con la adaptación ambiental.
The guarani group of Drosophila genus (Diptera: Drosophilidae) is formed by 24 species however th... more The guarani group of Drosophila genus (Diptera: Drosophilidae) is formed by 24 species however the relationship of these species is not clear. In the present study are described the karyotypes of Drosophila sachapuyu Peñafiel and Rafael, 2018 and Drosophila zamorana Peñafiel and Rafael, 2018, two Andean species members of the guarani group. Mitotic chromosomes from cerebral ganglia of third stand larval were obtained by thermal shock and cell suspension techniques. The karyotype of D. sachapuyu, presents 2n = 10 (4R, 1V; X = R, Y = R) while D. zamorana exhibits karyotype 2n = 12 (5R, 1V; X = V, Y = R).
Vaccinium floribundum Kunth, a wild native species of berry in Ecuador, presents a lot of phenoli... more Vaccinium floribundum Kunth, a wild native species of berry in Ecuador, presents a lot of phenolic compounds, specifically anthocyanins; hence it is considered a natural nutraceutical due to all its nutritional properties. The comparison of the expression of genes is involved in the biosynthesis pathway of anthocyanin of several populations. The aim of the research was to analyze the expression levels of three genes involved in the biosynthesis of anthocyanin in this species collected in two areas of the province of Pichincha: Machachi population of the Mejía canton, with geographic coordinates 0 ° 31′04.8 ″ S 78 ° 37′07.4 ″ W and altitude 3200 meters above sea level, and Pintag population of the Quito cantón, with geographic coordinates 0 ° 24′00.0 ″ S 78 ° 24′00.0 ″ W and altitude 3000 meters above sea level. The gene expression analysis was performed using the quantitative polymerase chain reaction technique and reverse transcription (RT-qPCR). For the population of Machachi, the...
Research on nanomaterial exposure-related health risks is still quite limited; this includes stan... more Research on nanomaterial exposure-related health risks is still quite limited; this includes standardizing methods for measuring metals in living organisms. Thus, this study validated an atomic absorption spectrophotometry method to determine fertility and bioaccumulated iron content in Drosophila melanogaster flies after feeding them magnetite nanoparticles (Fe3O4NPs) dosed in a culture medium (100, 250, 500, and 1000 mg kg−1). Some NPs were also coated with chitosan to compare iron assimilation. Considering both accuracy and precision, results showed the method was optimal for concentrations greater than 20 mg L−1. Recovery values were considered optimum within the 95–105% range. Regarding fertility, offspring for each coated and non-coated NPs concentration decreased in relation to the control group. Flies exposed to 100 mg L−1 of coated NPs presented the lowest fertility level and highest bioaccumulation factor. Despite an association between iron bioaccumulation and NPs concent...
Drosophila melanogaster hemolymph cells are confirmed as a model to study the activation of immun... more Drosophila melanogaster hemolymph cells are confirmed as a model to study the activation of immune system due to foreign stimuli like iron nanoparticles. The toxicity of nanoparticles is a cause for concern due to their effect on human health and the environment. The aim of this study was to detect the activation of cellular immune response in Drosophila larvae through the observation of hemolymph composition, DNA damage and larval viability, after the exposure to 500 ppm and 1000 ppm chitosan-coated magnetite nanoparticles for 24 hours. Our results showed activation of cellular immune response after exposure to the nanoparticles owing to the increment of hemocytes, the emergence of lamellocytes and the presence of apoptotic hemocytes. In addition, chitosan-coated magnetite nanoparticles produce DNA damage detected by comet assay as well as low viability of larvae. No DNA damage is showed at 500 ppm. The cellular toxicity is directly associated with 1000 ppm.
Revista Ecuatoriana de Medicina y Ciencias Biológicas, 2017
En el presente estudio se describen catorce nuevas especies del género Drosophila descubiertas re... more En el presente estudio se describen catorce nuevas especies del género Drosophila descubiertas recientemente en el Volcán Pasochoa, las nuevas especies pertenecen a cinco grupos de especies del género l. grupo repleta: Drosophila shuyu; 2. grupo tripunetata: Drosophila pataeorona, Drosophila quillu, Drosophila ninarumi, Drosophila surueueho, Drosophila iehubamba y Drosophila ureu; 3. grupo flavopilosa: Drosophila suni, Drosophila taxohuayeu y Drosophila sisa; 4. grupo guarani: Drosophila euseungu; 5. grupo annulimana: Drosophila yana y dos especies no agrupadas: Drosophila eondormaehay y Drosophila pugyu.
<p><b>A)</b> Interspecific cross and backcrosses used in experiments <b>B... more <p><b>A)</b> Interspecific cross and backcrosses used in experiments <b>B)</b> Selective PCR AFLP band patterns using primers with selective nucleotides GG (<i>Eco</i>RI) and CTG (<i>Mse</i>I). The arrows indicate two instability markers detected in hybrids from backcross 1 as an example. MWM, molecular weight marker; Dk, <i>D. koepferae</i>; Db, <i>D. buzzatii</i>; HF1, F1 hybrids; BC1, backcross 1.</p
Genome size (or C-value) can present a wide range of values among eukaryotes. This variation has ... more Genome size (or C-value) can present a wide range of values among eukaryotes. This variation has been attributed to differences in the amplification and deletion of different noncoding repetitive sequences, particularly transposable elements (TEs). TEs can be activated under different stress conditions such as interspecific hybridization events, as described for several species of animals and plants. These massive transposition episodes can lead to considerable genome expansions that could ultimately be involved in hybrid speciation processes. Here, we describe the effects of hybridization and introgression on genome size of Drosophila hybrids. We measured the genome size of two close Drosophila species, Drosophila buzzatii and Drosophila koepferae, their F 1 offspring and the offspring from three generations of backcrossed hybrids; where mobilization of up to 28 different TEs was previously detected. We show that hybrid females indeed present a genome expansion, especially in the first backcross, which could likely be explained by transposition events. Hybrid males, which exhibit more variable C-values among individuals of the same generation, do not present an increased genome size. Thus, we demonstrate that the impact of hybridization on genome size can be detected through flow cytometry and is sex-dependent.
An adapted amplified fragment length polymorphism (AFLP) protocol is presented for detection of h... more An adapted amplified fragment length polymorphism (AFLP) protocol is presented for detection of hybrid instability in the genome of interspecific hybrids between Drosophila buzzatii and D. koepferae species. Analyses of 15 AFLP instability markers (new bands detected in hybrids) show that up to 81% are the result of transposable element (TE) activity. Twenty TEs associated with AFLP instability markers have been detected by this method in backcross hybrids and segmental hybrids, demonstrating its validity in detecting transposition events occurring during the hybridization process. New insertions of Helena TE have been observed in the hybrid genome after hybridization of the TGTCG22 instability marker by FISH. The AFLP marker technique proved to be an efficient method that improves upon traditional and bioinformatic tools previously used to detect TE mobilization. This newly adapted AFLP protocol may also be applied to a large number of organisms outside the Drosophila genus, making...
Annals of the Entomological Society of America, 2002
ABSTRACT An unusual new species of Zygothrica, Z. desallei, is described from Ecuador. This speci... more ABSTRACT An unusual new species of Zygothrica, Z. desallei, is described from Ecuador. This species possesses three supernumerary crossveins extending from vein R2 + 3 to the costa. Such a phenotype, while observed in other drosophilid genera such as Jeannelopsis and Scaptomyza (Tantalia), has not been previously observed in Zygothrica.
Revista Ecuatoriana de Medicina y Ciencias Biológicas, 2017
En el Bosque Pasochoa, se encontraron tres nuevas especies del género Drosophila las cuales son d... more En el Bosque Pasochoa, se encontraron tres nuevas especies del género Drosophila las cuales son descritas en el presente artículo.
The mitotic metaphases of five Andean species of genus Drosophila are described for the first tim... more The mitotic metaphases of five Andean species of genus Drosophila are described for the first time. The evolutionary and interspecific genetic relationships within three Neotropical Drosophila species groups are analyzed. The diploid chromosome number for each species is as follows:
Revista Ecuatoriana de Medicina y Ciencias Biológicas (REMCB), May 6, 2022
Resumen.-Este trabajo recopila información sobre la expresión de los genes y proteínas de choque ... more Resumen.-Este trabajo recopila información sobre la expresión de los genes y proteínas de choque térmico en respuesta a los cambios de temperatura. Está enfocado en las especies más representativas de los órdenes de insectos más estudiados, a través de las cuales se compara la variación de la expresión de los genes Hsp y proteínas Hsp entre los órdenes y poblaciones de insectos y se expone su posible vínculo con la adaptación ambiental.
Drosophila melanogaster hemolymph cells are confirmed as a model to study the activation of immun... more Drosophila melanogaster hemolymph cells are confirmed as a model to study the activation of immune system due to foreign stimuli like iron nanoparticles. The toxicity of nanoparticles is a cause for concern due to their effect on human health and the environment. The aim of this study was to detect the activation of cellular immune response in Drosophila larvae through the observation of hemolymph composition, DNA damage and larval viability, after the exposure to 500 ppm and 1000 ppm chitosan-coated magnetite nanoparticles for 24 hours. Our results showed activation of cellular immune response after exposure to the nanoparticles owing to the increment of hemocytes, the emergence of lamellocytes and the presence of apoptotic hemocytes. In addition, chitosan-coated magnetite nanoparticles produce DNA damage detected by comet assay as well as low viability of larvae. No DNA damage is showed at 500 ppm. The cellular toxicity is directly associated with 1000 ppm.
Nanoparticles are a cause for concern because of their potential toxic effects on human health an... more Nanoparticles are a cause for concern because of their potential toxic effects on human health and the environment. The aim of this study was to assess the toxic effect of chitosan-coated magnetite nanoparticles (11.00±4.7 nm) on Drosophila melanogaster through the observation of hemolymph composition, DNA damage, larval survival and lifespan of flies. Chitosan-coated magnetite nanoparticles were synthesized by coprecipitation method. Drosophila larvaes and adults were exposed to 500 and 1000 ppm nanoparticles solution. After exposure, each type of larval hemocytes was recognized. Comet assay was performed to detect the DNA damage in the hemocytes. Also, the larval survival and lifespan of exposed flies were observed. Our results showed the toxic effect of the chitosan-coated magnetite nanoparticles through the increment of hemocytes, the emergence of lamellocytes, the presence of apoptotic hemocytes and the DNA damage detected by comet assay. In addition, nanoparticles produce decreasing of larval survival and shortening of the mean and maximum lifespan. The toxic effect the chitosan-coated magnetite nanoparticles is directly associated with 1000 ppm. No DNA damage was observed at 500 ppm.
Revista Ecuatoriana de Medicina y Ciencias Biológicas
Este trabajo recopila información sobre la expresión de los genes y proteínas de choque térmico e... more Este trabajo recopila información sobre la expresión de los genes y proteínas de choque térmico en respuesta a los cambios de temperatura. Está enfocado en las especies más representativas de los órdenes de insectos más estudiados, a través de las cuales se compara la variación de la expresión de los genes Hsp y proteínas Hsp entre los órdenes y poblaciones de insectos y se expone su posible vínculo con la adaptación ambiental.
The guarani group of Drosophila genus (Diptera: Drosophilidae) is formed by 24 species however th... more The guarani group of Drosophila genus (Diptera: Drosophilidae) is formed by 24 species however the relationship of these species is not clear. In the present study are described the karyotypes of Drosophila sachapuyu Peñafiel and Rafael, 2018 and Drosophila zamorana Peñafiel and Rafael, 2018, two Andean species members of the guarani group. Mitotic chromosomes from cerebral ganglia of third stand larval were obtained by thermal shock and cell suspension techniques. The karyotype of D. sachapuyu, presents 2n = 10 (4R, 1V; X = R, Y = R) while D. zamorana exhibits karyotype 2n = 12 (5R, 1V; X = V, Y = R).
Vaccinium floribundum Kunth, a wild native species of berry in Ecuador, presents a lot of phenoli... more Vaccinium floribundum Kunth, a wild native species of berry in Ecuador, presents a lot of phenolic compounds, specifically anthocyanins; hence it is considered a natural nutraceutical due to all its nutritional properties. The comparison of the expression of genes is involved in the biosynthesis pathway of anthocyanin of several populations. The aim of the research was to analyze the expression levels of three genes involved in the biosynthesis of anthocyanin in this species collected in two areas of the province of Pichincha: Machachi population of the Mejía canton, with geographic coordinates 0 ° 31′04.8 ″ S 78 ° 37′07.4 ″ W and altitude 3200 meters above sea level, and Pintag population of the Quito cantón, with geographic coordinates 0 ° 24′00.0 ″ S 78 ° 24′00.0 ″ W and altitude 3000 meters above sea level. The gene expression analysis was performed using the quantitative polymerase chain reaction technique and reverse transcription (RT-qPCR). For the population of Machachi, the...
Research on nanomaterial exposure-related health risks is still quite limited; this includes stan... more Research on nanomaterial exposure-related health risks is still quite limited; this includes standardizing methods for measuring metals in living organisms. Thus, this study validated an atomic absorption spectrophotometry method to determine fertility and bioaccumulated iron content in Drosophila melanogaster flies after feeding them magnetite nanoparticles (Fe3O4NPs) dosed in a culture medium (100, 250, 500, and 1000 mg kg−1). Some NPs were also coated with chitosan to compare iron assimilation. Considering both accuracy and precision, results showed the method was optimal for concentrations greater than 20 mg L−1. Recovery values were considered optimum within the 95–105% range. Regarding fertility, offspring for each coated and non-coated NPs concentration decreased in relation to the control group. Flies exposed to 100 mg L−1 of coated NPs presented the lowest fertility level and highest bioaccumulation factor. Despite an association between iron bioaccumulation and NPs concent...
Drosophila melanogaster hemolymph cells are confirmed as a model to study the activation of immun... more Drosophila melanogaster hemolymph cells are confirmed as a model to study the activation of immune system due to foreign stimuli like iron nanoparticles. The toxicity of nanoparticles is a cause for concern due to their effect on human health and the environment. The aim of this study was to detect the activation of cellular immune response in Drosophila larvae through the observation of hemolymph composition, DNA damage and larval viability, after the exposure to 500 ppm and 1000 ppm chitosan-coated magnetite nanoparticles for 24 hours. Our results showed activation of cellular immune response after exposure to the nanoparticles owing to the increment of hemocytes, the emergence of lamellocytes and the presence of apoptotic hemocytes. In addition, chitosan-coated magnetite nanoparticles produce DNA damage detected by comet assay as well as low viability of larvae. No DNA damage is showed at 500 ppm. The cellular toxicity is directly associated with 1000 ppm.
Revista Ecuatoriana de Medicina y Ciencias Biológicas, 2017
En el presente estudio se describen catorce nuevas especies del género Drosophila descubiertas re... more En el presente estudio se describen catorce nuevas especies del género Drosophila descubiertas recientemente en el Volcán Pasochoa, las nuevas especies pertenecen a cinco grupos de especies del género l. grupo repleta: Drosophila shuyu; 2. grupo tripunetata: Drosophila pataeorona, Drosophila quillu, Drosophila ninarumi, Drosophila surueueho, Drosophila iehubamba y Drosophila ureu; 3. grupo flavopilosa: Drosophila suni, Drosophila taxohuayeu y Drosophila sisa; 4. grupo guarani: Drosophila euseungu; 5. grupo annulimana: Drosophila yana y dos especies no agrupadas: Drosophila eondormaehay y Drosophila pugyu.
<p><b>A)</b> Interspecific cross and backcrosses used in experiments <b>B... more <p><b>A)</b> Interspecific cross and backcrosses used in experiments <b>B)</b> Selective PCR AFLP band patterns using primers with selective nucleotides GG (<i>Eco</i>RI) and CTG (<i>Mse</i>I). The arrows indicate two instability markers detected in hybrids from backcross 1 as an example. MWM, molecular weight marker; Dk, <i>D. koepferae</i>; Db, <i>D. buzzatii</i>; HF1, F1 hybrids; BC1, backcross 1.</p
Genome size (or C-value) can present a wide range of values among eukaryotes. This variation has ... more Genome size (or C-value) can present a wide range of values among eukaryotes. This variation has been attributed to differences in the amplification and deletion of different noncoding repetitive sequences, particularly transposable elements (TEs). TEs can be activated under different stress conditions such as interspecific hybridization events, as described for several species of animals and plants. These massive transposition episodes can lead to considerable genome expansions that could ultimately be involved in hybrid speciation processes. Here, we describe the effects of hybridization and introgression on genome size of Drosophila hybrids. We measured the genome size of two close Drosophila species, Drosophila buzzatii and Drosophila koepferae, their F 1 offspring and the offspring from three generations of backcrossed hybrids; where mobilization of up to 28 different TEs was previously detected. We show that hybrid females indeed present a genome expansion, especially in the first backcross, which could likely be explained by transposition events. Hybrid males, which exhibit more variable C-values among individuals of the same generation, do not present an increased genome size. Thus, we demonstrate that the impact of hybridization on genome size can be detected through flow cytometry and is sex-dependent.
An adapted amplified fragment length polymorphism (AFLP) protocol is presented for detection of h... more An adapted amplified fragment length polymorphism (AFLP) protocol is presented for detection of hybrid instability in the genome of interspecific hybrids between Drosophila buzzatii and D. koepferae species. Analyses of 15 AFLP instability markers (new bands detected in hybrids) show that up to 81% are the result of transposable element (TE) activity. Twenty TEs associated with AFLP instability markers have been detected by this method in backcross hybrids and segmental hybrids, demonstrating its validity in detecting transposition events occurring during the hybridization process. New insertions of Helena TE have been observed in the hybrid genome after hybridization of the TGTCG22 instability marker by FISH. The AFLP marker technique proved to be an efficient method that improves upon traditional and bioinformatic tools previously used to detect TE mobilization. This newly adapted AFLP protocol may also be applied to a large number of organisms outside the Drosophila genus, making...
Annals of the Entomological Society of America, 2002
ABSTRACT An unusual new species of Zygothrica, Z. desallei, is described from Ecuador. This speci... more ABSTRACT An unusual new species of Zygothrica, Z. desallei, is described from Ecuador. This species possesses three supernumerary crossveins extending from vein R2 + 3 to the costa. Such a phenotype, while observed in other drosophilid genera such as Jeannelopsis and Scaptomyza (Tantalia), has not been previously observed in Zygothrica.
Revista Ecuatoriana de Medicina y Ciencias Biológicas, 2017
En el Bosque Pasochoa, se encontraron tres nuevas especies del género Drosophila las cuales son d... more En el Bosque Pasochoa, se encontraron tres nuevas especies del género Drosophila las cuales son descritas en el presente artículo.
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