Daniele Matoso - Academia.edu (original) (raw)

Papers by Daniele Matoso

Animals

Rex retroelements are the best-known transposable elements class and are broadly distributed thro... more Rex retroelements are the best-known transposable elements class and are broadly distributed through fish and also individual genomes, playing an important role in their evolutionary dynamics. Several agents can stress these elements; among them, there are some parasitic compounds such as the organochlorophosphate Trichlorfon. Consequently, knowing that the organochlorophosphate Trichlorfon is indiscriminately used as an antiparasitic in aquaculture, the current study aimed to analyze the effects of this compound on the activation of the Transposable Elements (TEs) Rex1, Rex3, and Rex6 and the structure of heterochromatin in the mitotic chromosomes of the tambaqui (Colossoma macropomum). For this, two concentrations of the pesticide were used: 30% (0.261 mg/L) and 50% (0.435 mg/L) of the recommended LC50–96 h concentration (0.87 mg/L) for this fish species. The results revealed a dispersed distribution for Rex1 and Rex6 retroelements. Rex3 showed an increase in both marking intensit...

Zoosystematics and Evolution, 2021

Ceratomyxa amazonensis is a cnidarian myxosporean originally described with strongly arcuate cres... more Ceratomyxa amazonensis is a cnidarian myxosporean originally described with strongly arcuate crescent-shaped myxospores, absence of vegetative stages and infecting Symphysodon discus, an important Amazonian ornamental fish in the aquarium industry. As part of a long-term investigation concerning myxosporeans that infect discus fish Symphysodon spp. from different rivers of the Amazon Basin, thirty specimens of S. discus collected from Unini River were examined. Plasmodial vegetative stages therefrom were found freely floating in the bile of gall bladders from eighteen fish. Mature myxospores were slightly crescent-shaped, measuring 4.72 ± 0.1 (4.52–4.81) μm in length, 24.2 ± 0.4 (23.9–25.3) μm in thickness with polar capsules 2.31 ± 0.1 (2.29–2.33) μm in length and 2.15 ± 0.1 (2.13–2.17) μm in width. Strong morphological differences were observed between the newly isolated myxospores obtained and the previously described C. amazonensis; however, molecular assessment, based on 18S rD...

Cytogenetics - Classical and Molecular Strategies for Analysing Heredity Material, 2021

Fishes of the genus Gymnotus have been suggested as a good model for biogeographic studies in the... more Fishes of the genus Gymnotus have been suggested as a good model for biogeographic studies in the South American continent. In relation to heterochromatin, species of this genus have blocks preferably distributed in the centromeric region. The content of these regions has been shown to be variable, with description of transposable elements, pseudogenes of 5S rDNA and satellite sequences. In G. carapo Clade, although geographically separated, species with 2n = 54 chromosomes share the distribution of many 5S rDNA sites, a unique case within the genus. Here, repetitive DNA sequences from G. sylvius (2n = 40) and G. paraguensis (2n = 54) were isolated and mapped to understand their constitution. The chromosome mapping by FISH showed an exclusive association in the centromeres of all chromosomes. However, the cross-FISH did not show positive signs of interspecific hybridization, indicating high levels of heterochromatic sequence specificity. In addition, COI-1 sequences were analyzed in...

Cytogenetics - Classical and Molecular Strategies for Analysing Heredity Material, 2021

Transcriptionally inactive portions of genomic DNA, condensed with histones and architectural pro... more Transcriptionally inactive portions of genomic DNA, condensed with histones and architectural proteins, are known as heterochromatic regions, often positive C band. The advent of epigenetics and new methodological approaches, showed that these regions are extremely dynamic and responsive to different types of environmental stress. The relationship of the constitutive heterochromatin with the transposable elements inactivation, especially from the Rex family, seems to be a frequent condition in fish. In this manuscript we review the existing knowledge of the nature and function of these genomic regions, based on species-based studies, with a focus on species of fish from the Amazon region.

Aquaculture International, 2019

In Brazilian fish farms, trichlorfon has been widely used to control acanthocephalan infections i... more In Brazilian fish farms, trichlorfon has been widely used to control acanthocephalan infections in Colossoma macropomum. Toxicity tests were conducted to estimate the median lethal concentration (LC50–96 h) and evaluate the effects of trichlorfon on acetylcholinesterase (AChE) and glutathione S-transferase (GST) from different tissues of C. macropomum. The LC50–96 h of trichlorfon was estimated to be 0.87 mg L−1. In the sublethal toxicity tests, concentrations of 0.26 mg L−1 (30% of LC50–96 h) and 0.43 mg L−1 (50% of LC50–96 h) were used. AChE and GST activities were measured in the brain, muscle, intestine, and liver. In vitro studies were conducted to estimate the kinetic properties and half-maximal inhibitory concentration (IC50) values of AChE in the brain and muscle for trichlorfon. In the sublethal toxicity experiments, inhibition of more than 90% of AChE in the brain, muscle, and intestine was observed. However, the activity of GST did not vary in any of the tissues studied. This finding suggests that trichlorfon is not metabolised by this enzyme. The in vitro assay results suggest that trichlorfon tends to be a classic uncompetitive inhibitor of AChE in both the brain and muscle, since Km and Vmax values decrease, while the slope remains unchanged. The IC50 values of muscle AChE are lower than those of the brain. All these results show that C. macropomum has low tolerance to this pesticide and suggest that brain AChE can be used as a biochemical biomarker, while muscle AChE may be used as an indicator of mortality in toxicological studies.

Zebrafish, 2016

The Ancistrus genus differs from other Ancistrini due to its wide karyotypic diversity, varied di... more The Ancistrus genus differs from other Ancistrini due to its wide karyotypic diversity, varied diploid numbers, differences in sex chromosomes, and large number of species, as well as its tendency to form small populations with low vagility. This study investigated the role of 5S and 18S rDNA and telomeric repetitive sequences in the evolution of the karyotypic macrostructure of seven species of the genus Ancistrus from the Central Amazon. The results indicate a strong correlation between the location of ribosomal sites and fragile sites in the genome, particularly of 5S rDNA sequences, which are associated, in some species, with telomeric sequences at the sites of chromosomal healing. Moreover, the occurrence of two lineages was observed with regard to the synteny of ribosomal genes. The species of the genus Ancistrus showed high chromosomal lability associated with breakpoints, which was characterized by the presence of repetitive DNA sequences and this process is suggested to be ...

Cytogenetic and Genome Research, 2020

The family Aspredinidae comprises a clade of complex systematic relationships, both from molecula... more The family Aspredinidae comprises a clade of complex systematic relationships, both from molecular and morphological approaches. In this study, conventional and molecular cytogenetic studies coupled with nucleotide sequencing were performed in 6 Aspredininae species (Amaralia hypsiura, Bunocephalus cf. aloikae, Bunocephalus amaurus, Bunocephalus aff. coracoideus, Bunocephalus verrucosus, and Platystacus cotylephorus) from different locations of the Amazon hydrographic basin. Our results showed highly divergent diploid numbers (2n) among the species, ranging from 49 to 74, including the occurrence of an XX/X0 sex chromosome system. A neighbor-joining phylogram based on the cytochrome c oxidase I (COI) showed that Bunocephalus coracoideus is not a monophyletic clade, but closely related to B. verrucosus. The karyotypic data associated with COI suggest an ancestral karyotype for Aspredinidae with a reduced 2n, composed of bi-armed chromosomes and a trend toward chromosomal fissions res...

Cytogenetic and Genome Research, 2019

Greenhouse gas emissions are known to influence the planet's temperature, mainly due to human... more Greenhouse gas emissions are known to influence the planet's temperature, mainly due to human activities. To allow hypothesis testing, as well as to seek viable alternatives for mitigation, the Intergovernmental Panel on Climate Change (IPCC) suggested 3 main scenarios for changes projected for the year 2100. In this paper, we subjected Colossoma macropomum Cuvier, 1818 (tambaqui) individuals in a microcosm to IPCC scenarios B1 (mild), A1B (intermediate), and A2 (extreme) to test possible impacts on their genome. We found chromosome heterochromatinization in specimens exposed to the A2 scenario, where terminal blocks and interstitial bands were detected on several chromosome pairs. The behavior of Rex1 and Rex3 sequences differed between the test scenarios. Hybridization of Rex1 resulted in diffuse signals which showed a gradual increase in the tested scenarios. For Rex3, an increase was observed in the A2 scenario with blocks on several chromosomes, some of which coincided with...

Zebrafish, 2019

Electric fish of the order Gymnotiformes are endemic to the Neotropical region, and their highest... more Electric fish of the order Gymnotiformes are endemic to the Neotropical region, and their highest diversity is observed in the Amazon region. The family Gymnotidae, which consists of the genera Electrophorus and Gymnotus, is a natural group and is located at the base of the phylogeny of the order. Gymnotus is a widely distributed and specious genus with high karyotypic diversity, especially concerning to the diploid number and the locations of repetitive sequences. Our karyotyping results in five species of the family Gymnotidae (Gymnotus ucamara, Gymnotus cf. stenoleucus, Gymnotus cf. pedanopterus, Gymnotus mamiraua, and Gymnotus carapo "Maranhão") corroborate the proposal of plasticity of the diploid number in this group. Moreover, in this study, we propose that the 5S ribosomal DNA (rDNA) sequences were species-specific markers that act as a potential biogeographical marker for the genus. Besides, the sequence's location, particularly in G. mamiraua from Central Amazon, shows a close relationship with 5S of the Gymnotus species, with 54 chromosomes, from the Paraná-Paraguay basin in the Center-South of Brazil. Considering that the ancestral diploid number for Gymnotidae is 52 chromosomes, we also suggest that the trend in the family is toward a decrease in the chromosome number. However, the carapo clade stands out in this regard, with an increase and a decrease in chromosome number; this pattern may be reinforced with the ecologic behaviors and the geodispersal patterns of this clade.

Publicatio UEPG: Ciencias Biologicas e da Saude, 2004

Inúmeros trabalhos foram realizados com marcadores moleculares, nas 4 últimas décadas. Isso foi p... more Inúmeros trabalhos foram realizados com marcadores moleculares, nas 4 últimas décadas. Isso foi possível devido ao surgimento de sofisticadas técnicas de resolução de polimorfismos de proteínas e DNA. No que diz respeito aos peixes de água doce, cuja região neotropical é caracterizada como a mais diversificada em número de espécies e densidade populacional, a biologia molecular tem disponibilizado diversas ferramentas capazes de acessar a variação genética existente nesses grupos e relacioná-la a fatores ambientais e antrópicos. Dessa forma, tem-se verificado a emergência de artigos versando sobre variação genética, filogenética, filogeográfica, ecológica, dentre outros aspectos da dinâmica biológica dos peixes. O presente trabalho tem como objetivo apresentar uma revisão bibliográfica sobre as metodologias básicas de estudo da área de biologia molecular, frente às tendências gerais de análise em biologia evolutiva de peixes de água doce na região neotropical.

Environmental Technology & Innovation, 2019

Abstract The HpaII/MspI-PCR is a method based on the sensitivity of restriction enzymes to methyl... more Abstract The HpaII/MspI-PCR is a method based on the sensitivity of restriction enzymes to methylation at their cleavage sites, which permits the comparison of the DNA methylation status of different organisms, based on the differential patterns of digestion. Prior to the present study, nothing was known of the methylation profile of specific DNA sequences in Amazonian fish based on enzymes sensitive to methylation. Given this, the present study investigated the methylation profile of the 18S rRNA gene of the armored catfish, Hoplosternum littorale, which inhabits relatively inhospitable environments in the Amazon basin. A differential methylation profile was found in the 18S rRNA sites, indicating that polluted environments may influence the methylation of DNA, and would have evolved in the species, initially, as a defense mechanism against the expression of transposable elements.

Frontiers in Genetics, 2017

Journal of Heredity, 2016

Repetitive DNA sequences are present in the genome of basically every known organism, and transpo... more Repetitive DNA sequences are present in the genome of basically every known organism, and transposable elements (TE) are one of the most representative sequences involved in chromosomal rearrangements and the genomic evolution of eukaryotes. In fish, the non-LTR retrotransposon TEs, Rex1, Rex3, and Rex6, are widely distributed in fish genomes and are the best-characterized TEs in several species. In the current study, three of these retroelements were physically mapped, through fluorescent in situ hybridization (FISH), in 7 species (71 specimens) of the genus Ancistrus, known as bristlenose catfish: Ancistrus ranunculus, Ancistrus sp. 1 "Purus," Ancistrus sp. 2 "Catalão," Ancistrus dolichopterus, Ancistrus maximus, Ancistrus aff. dolichopterus, and Ancistrus dubius. Rex1, Rex3, and Rex6 showed a cluster distribution, mainly in the terminal and pericentromeric portions, in heterochromatic and euchromatic regions, and did not occur in sexual chromosomes; however, the number and position of the clusters varied between species. This TE distribution suggests its implication in the karyotypic evolution of these species, without affecting the rise of sexual chromosome systems in Ancistrus, in view of their chromosomal variation.

Genetica, 2016

We analyzed one Bunocephalus coracoideus population from the Negro River basin using cytogenetic ... more We analyzed one Bunocephalus coracoideus population from the Negro River basin using cytogenetic techniques. The results showed a diploid number of 42 chromosomes in both sexes, with the karyotypic formula 4m + 14sm + 24a and fundamental number (FN) = 60 for females and the formula 5m + 14sm + 23a and FN = 61 for males, constituting an X1X1X2X2/X1Y1X2Y2 multiple sex chromosome system. The constitutive heterochromatin is distributed in the pericentromeric regions of most of the chromosomes, except for the sex chromosomes, of which the X1, X2, and Y1 chromosomes were euchromatic and the Y2 chromosome was partially heterochromatic. 18S rDNA mapping confirmed the presence of nucleolar organizer regions on the short arms of the fifth chromosomal pair for both sexes. The 5S rDNA is present in the terminal regions of the short arms on the 2nd, 10th, and 12th pairs and on the X2 chromosome of both sexes; however, we observed variations in the presence of these ribosomal cistrons on the Y1 chromosome, on which the cistrons are pericentromeric, and on the Y2 chromosome, on which these cistrons are present in the terminal portions of the short and long arms. Telomeric sequences are located in the terminal regions of all of the chromosomes, particularly conspicuous blocks on the 10th and 12th pairs and internal telomeric sequences in the centromeric regions of the 1st, 6th, and 9th pairs for both sexes. This work describes an new sex chromosomes system for the Siluriformes and increases our genetic knowledge of the Aspredinidae family.

Neotropical Ichthyology, 2011

Zebrafish, 2014

Antagonist sexual selection is the driving force behind the origin and diversification of sex chr... more Antagonist sexual selection is the driving force behind the origin and diversification of sex chromosomes such as XX/XY and ZZ/ZW. However, chromosome mobility, mainly in fishes, may result in the formation of chromosomes of recent origin, a process known as turnover. The family Gymnotidae, which is composed of the genera Electrophorus+Gymnotus, presents a multiple system of the type X1X1X2X2/X1X2Y, which has been described for Gymnotus pantanal. This article describes the karyotype of three Amazon Gymnotus species, revealing the presence of both simple and multiple systems: Gymnotus carapo "Catalão" 2n=40 XX/XY, Gymnotus coropinae 2n=49♂/50♀ X1X1X2X2/X1X2Y, and Gymnotus sp. "Negro" 2n=50 XX/XY. Our hypothesis is that the simple system present in G. carapo "Catalão" is ancestral in relation to G. pantanal's multiple system and that the diversification of the subsequent multiple system occurred after the final separation of the Amazon and Paraná basins. Moreover, G. coropinae's multiple system may have originated from the simple system present in Gymnotus sp. "Negro." The distant position between the species in the Gymnotidae family's phylogeny in addition to differences in sex chromosome formula and number between Clade G1 G. coropinae and G. sp. "Negro" species and "Carapo" Clade. G. carapo and G. pantanal species suggest that both sequences of sexual systems occurred independently, supporting other proposed models and highlighting the fact that species of the genus Gymnotus may serve as a model for studying sex chromosome turnover.

Reviews in Fish Biology and Fisheries, 2011

Animals

Rex retroelements are the best-known transposable elements class and are broadly distributed thro... more Rex retroelements are the best-known transposable elements class and are broadly distributed through fish and also individual genomes, playing an important role in their evolutionary dynamics. Several agents can stress these elements; among them, there are some parasitic compounds such as the organochlorophosphate Trichlorfon. Consequently, knowing that the organochlorophosphate Trichlorfon is indiscriminately used as an antiparasitic in aquaculture, the current study aimed to analyze the effects of this compound on the activation of the Transposable Elements (TEs) Rex1, Rex3, and Rex6 and the structure of heterochromatin in the mitotic chromosomes of the tambaqui (Colossoma macropomum). For this, two concentrations of the pesticide were used: 30% (0.261 mg/L) and 50% (0.435 mg/L) of the recommended LC50–96 h concentration (0.87 mg/L) for this fish species. The results revealed a dispersed distribution for Rex1 and Rex6 retroelements. Rex3 showed an increase in both marking intensit...

Zoosystematics and Evolution, 2021

Ceratomyxa amazonensis is a cnidarian myxosporean originally described with strongly arcuate cres... more Ceratomyxa amazonensis is a cnidarian myxosporean originally described with strongly arcuate crescent-shaped myxospores, absence of vegetative stages and infecting Symphysodon discus, an important Amazonian ornamental fish in the aquarium industry. As part of a long-term investigation concerning myxosporeans that infect discus fish Symphysodon spp. from different rivers of the Amazon Basin, thirty specimens of S. discus collected from Unini River were examined. Plasmodial vegetative stages therefrom were found freely floating in the bile of gall bladders from eighteen fish. Mature myxospores were slightly crescent-shaped, measuring 4.72 ± 0.1 (4.52–4.81) μm in length, 24.2 ± 0.4 (23.9–25.3) μm in thickness with polar capsules 2.31 ± 0.1 (2.29–2.33) μm in length and 2.15 ± 0.1 (2.13–2.17) μm in width. Strong morphological differences were observed between the newly isolated myxospores obtained and the previously described C. amazonensis; however, molecular assessment, based on 18S rD...

Cytogenetics - Classical and Molecular Strategies for Analysing Heredity Material, 2021

Fishes of the genus Gymnotus have been suggested as a good model for biogeographic studies in the... more Fishes of the genus Gymnotus have been suggested as a good model for biogeographic studies in the South American continent. In relation to heterochromatin, species of this genus have blocks preferably distributed in the centromeric region. The content of these regions has been shown to be variable, with description of transposable elements, pseudogenes of 5S rDNA and satellite sequences. In G. carapo Clade, although geographically separated, species with 2n = 54 chromosomes share the distribution of many 5S rDNA sites, a unique case within the genus. Here, repetitive DNA sequences from G. sylvius (2n = 40) and G. paraguensis (2n = 54) were isolated and mapped to understand their constitution. The chromosome mapping by FISH showed an exclusive association in the centromeres of all chromosomes. However, the cross-FISH did not show positive signs of interspecific hybridization, indicating high levels of heterochromatic sequence specificity. In addition, COI-1 sequences were analyzed in...

Cytogenetics - Classical and Molecular Strategies for Analysing Heredity Material, 2021

Transcriptionally inactive portions of genomic DNA, condensed with histones and architectural pro... more Transcriptionally inactive portions of genomic DNA, condensed with histones and architectural proteins, are known as heterochromatic regions, often positive C band. The advent of epigenetics and new methodological approaches, showed that these regions are extremely dynamic and responsive to different types of environmental stress. The relationship of the constitutive heterochromatin with the transposable elements inactivation, especially from the Rex family, seems to be a frequent condition in fish. In this manuscript we review the existing knowledge of the nature and function of these genomic regions, based on species-based studies, with a focus on species of fish from the Amazon region.

Aquaculture International, 2019

In Brazilian fish farms, trichlorfon has been widely used to control acanthocephalan infections i... more In Brazilian fish farms, trichlorfon has been widely used to control acanthocephalan infections in Colossoma macropomum. Toxicity tests were conducted to estimate the median lethal concentration (LC50–96 h) and evaluate the effects of trichlorfon on acetylcholinesterase (AChE) and glutathione S-transferase (GST) from different tissues of C. macropomum. The LC50–96 h of trichlorfon was estimated to be 0.87 mg L−1. In the sublethal toxicity tests, concentrations of 0.26 mg L−1 (30% of LC50–96 h) and 0.43 mg L−1 (50% of LC50–96 h) were used. AChE and GST activities were measured in the brain, muscle, intestine, and liver. In vitro studies were conducted to estimate the kinetic properties and half-maximal inhibitory concentration (IC50) values of AChE in the brain and muscle for trichlorfon. In the sublethal toxicity experiments, inhibition of more than 90% of AChE in the brain, muscle, and intestine was observed. However, the activity of GST did not vary in any of the tissues studied. This finding suggests that trichlorfon is not metabolised by this enzyme. The in vitro assay results suggest that trichlorfon tends to be a classic uncompetitive inhibitor of AChE in both the brain and muscle, since Km and Vmax values decrease, while the slope remains unchanged. The IC50 values of muscle AChE are lower than those of the brain. All these results show that C. macropomum has low tolerance to this pesticide and suggest that brain AChE can be used as a biochemical biomarker, while muscle AChE may be used as an indicator of mortality in toxicological studies.

Zebrafish, 2016

The Ancistrus genus differs from other Ancistrini due to its wide karyotypic diversity, varied di... more The Ancistrus genus differs from other Ancistrini due to its wide karyotypic diversity, varied diploid numbers, differences in sex chromosomes, and large number of species, as well as its tendency to form small populations with low vagility. This study investigated the role of 5S and 18S rDNA and telomeric repetitive sequences in the evolution of the karyotypic macrostructure of seven species of the genus Ancistrus from the Central Amazon. The results indicate a strong correlation between the location of ribosomal sites and fragile sites in the genome, particularly of 5S rDNA sequences, which are associated, in some species, with telomeric sequences at the sites of chromosomal healing. Moreover, the occurrence of two lineages was observed with regard to the synteny of ribosomal genes. The species of the genus Ancistrus showed high chromosomal lability associated with breakpoints, which was characterized by the presence of repetitive DNA sequences and this process is suggested to be ...

Cytogenetic and Genome Research, 2020

The family Aspredinidae comprises a clade of complex systematic relationships, both from molecula... more The family Aspredinidae comprises a clade of complex systematic relationships, both from molecular and morphological approaches. In this study, conventional and molecular cytogenetic studies coupled with nucleotide sequencing were performed in 6 Aspredininae species (Amaralia hypsiura, Bunocephalus cf. aloikae, Bunocephalus amaurus, Bunocephalus aff. coracoideus, Bunocephalus verrucosus, and Platystacus cotylephorus) from different locations of the Amazon hydrographic basin. Our results showed highly divergent diploid numbers (2n) among the species, ranging from 49 to 74, including the occurrence of an XX/X0 sex chromosome system. A neighbor-joining phylogram based on the cytochrome c oxidase I (COI) showed that Bunocephalus coracoideus is not a monophyletic clade, but closely related to B. verrucosus. The karyotypic data associated with COI suggest an ancestral karyotype for Aspredinidae with a reduced 2n, composed of bi-armed chromosomes and a trend toward chromosomal fissions res...

Cytogenetic and Genome Research, 2019

Greenhouse gas emissions are known to influence the planet's temperature, mainly due to human... more Greenhouse gas emissions are known to influence the planet's temperature, mainly due to human activities. To allow hypothesis testing, as well as to seek viable alternatives for mitigation, the Intergovernmental Panel on Climate Change (IPCC) suggested 3 main scenarios for changes projected for the year 2100. In this paper, we subjected Colossoma macropomum Cuvier, 1818 (tambaqui) individuals in a microcosm to IPCC scenarios B1 (mild), A1B (intermediate), and A2 (extreme) to test possible impacts on their genome. We found chromosome heterochromatinization in specimens exposed to the A2 scenario, where terminal blocks and interstitial bands were detected on several chromosome pairs. The behavior of Rex1 and Rex3 sequences differed between the test scenarios. Hybridization of Rex1 resulted in diffuse signals which showed a gradual increase in the tested scenarios. For Rex3, an increase was observed in the A2 scenario with blocks on several chromosomes, some of which coincided with...

Zebrafish, 2019

Electric fish of the order Gymnotiformes are endemic to the Neotropical region, and their highest... more Electric fish of the order Gymnotiformes are endemic to the Neotropical region, and their highest diversity is observed in the Amazon region. The family Gymnotidae, which consists of the genera Electrophorus and Gymnotus, is a natural group and is located at the base of the phylogeny of the order. Gymnotus is a widely distributed and specious genus with high karyotypic diversity, especially concerning to the diploid number and the locations of repetitive sequences. Our karyotyping results in five species of the family Gymnotidae (Gymnotus ucamara, Gymnotus cf. stenoleucus, Gymnotus cf. pedanopterus, Gymnotus mamiraua, and Gymnotus carapo "Maranhão") corroborate the proposal of plasticity of the diploid number in this group. Moreover, in this study, we propose that the 5S ribosomal DNA (rDNA) sequences were species-specific markers that act as a potential biogeographical marker for the genus. Besides, the sequence's location, particularly in G. mamiraua from Central Amazon, shows a close relationship with 5S of the Gymnotus species, with 54 chromosomes, from the Paraná-Paraguay basin in the Center-South of Brazil. Considering that the ancestral diploid number for Gymnotidae is 52 chromosomes, we also suggest that the trend in the family is toward a decrease in the chromosome number. However, the carapo clade stands out in this regard, with an increase and a decrease in chromosome number; this pattern may be reinforced with the ecologic behaviors and the geodispersal patterns of this clade.

Publicatio UEPG: Ciencias Biologicas e da Saude, 2004

Inúmeros trabalhos foram realizados com marcadores moleculares, nas 4 últimas décadas. Isso foi p... more Inúmeros trabalhos foram realizados com marcadores moleculares, nas 4 últimas décadas. Isso foi possível devido ao surgimento de sofisticadas técnicas de resolução de polimorfismos de proteínas e DNA. No que diz respeito aos peixes de água doce, cuja região neotropical é caracterizada como a mais diversificada em número de espécies e densidade populacional, a biologia molecular tem disponibilizado diversas ferramentas capazes de acessar a variação genética existente nesses grupos e relacioná-la a fatores ambientais e antrópicos. Dessa forma, tem-se verificado a emergência de artigos versando sobre variação genética, filogenética, filogeográfica, ecológica, dentre outros aspectos da dinâmica biológica dos peixes. O presente trabalho tem como objetivo apresentar uma revisão bibliográfica sobre as metodologias básicas de estudo da área de biologia molecular, frente às tendências gerais de análise em biologia evolutiva de peixes de água doce na região neotropical.

Environmental Technology & Innovation, 2019

Abstract The HpaII/MspI-PCR is a method based on the sensitivity of restriction enzymes to methyl... more Abstract The HpaII/MspI-PCR is a method based on the sensitivity of restriction enzymes to methylation at their cleavage sites, which permits the comparison of the DNA methylation status of different organisms, based on the differential patterns of digestion. Prior to the present study, nothing was known of the methylation profile of specific DNA sequences in Amazonian fish based on enzymes sensitive to methylation. Given this, the present study investigated the methylation profile of the 18S rRNA gene of the armored catfish, Hoplosternum littorale, which inhabits relatively inhospitable environments in the Amazon basin. A differential methylation profile was found in the 18S rRNA sites, indicating that polluted environments may influence the methylation of DNA, and would have evolved in the species, initially, as a defense mechanism against the expression of transposable elements.

Frontiers in Genetics, 2017

Journal of Heredity, 2016

Repetitive DNA sequences are present in the genome of basically every known organism, and transpo... more Repetitive DNA sequences are present in the genome of basically every known organism, and transposable elements (TE) are one of the most representative sequences involved in chromosomal rearrangements and the genomic evolution of eukaryotes. In fish, the non-LTR retrotransposon TEs, Rex1, Rex3, and Rex6, are widely distributed in fish genomes and are the best-characterized TEs in several species. In the current study, three of these retroelements were physically mapped, through fluorescent in situ hybridization (FISH), in 7 species (71 specimens) of the genus Ancistrus, known as bristlenose catfish: Ancistrus ranunculus, Ancistrus sp. 1 "Purus," Ancistrus sp. 2 "Catalão," Ancistrus dolichopterus, Ancistrus maximus, Ancistrus aff. dolichopterus, and Ancistrus dubius. Rex1, Rex3, and Rex6 showed a cluster distribution, mainly in the terminal and pericentromeric portions, in heterochromatic and euchromatic regions, and did not occur in sexual chromosomes; however, the number and position of the clusters varied between species. This TE distribution suggests its implication in the karyotypic evolution of these species, without affecting the rise of sexual chromosome systems in Ancistrus, in view of their chromosomal variation.

Genetica, 2016

We analyzed one Bunocephalus coracoideus population from the Negro River basin using cytogenetic ... more We analyzed one Bunocephalus coracoideus population from the Negro River basin using cytogenetic techniques. The results showed a diploid number of 42 chromosomes in both sexes, with the karyotypic formula 4m + 14sm + 24a and fundamental number (FN) = 60 for females and the formula 5m + 14sm + 23a and FN = 61 for males, constituting an X1X1X2X2/X1Y1X2Y2 multiple sex chromosome system. The constitutive heterochromatin is distributed in the pericentromeric regions of most of the chromosomes, except for the sex chromosomes, of which the X1, X2, and Y1 chromosomes were euchromatic and the Y2 chromosome was partially heterochromatic. 18S rDNA mapping confirmed the presence of nucleolar organizer regions on the short arms of the fifth chromosomal pair for both sexes. The 5S rDNA is present in the terminal regions of the short arms on the 2nd, 10th, and 12th pairs and on the X2 chromosome of both sexes; however, we observed variations in the presence of these ribosomal cistrons on the Y1 chromosome, on which the cistrons are pericentromeric, and on the Y2 chromosome, on which these cistrons are present in the terminal portions of the short and long arms. Telomeric sequences are located in the terminal regions of all of the chromosomes, particularly conspicuous blocks on the 10th and 12th pairs and internal telomeric sequences in the centromeric regions of the 1st, 6th, and 9th pairs for both sexes. This work describes an new sex chromosomes system for the Siluriformes and increases our genetic knowledge of the Aspredinidae family.

Neotropical Ichthyology, 2011

Zebrafish, 2014

Antagonist sexual selection is the driving force behind the origin and diversification of sex chr... more Antagonist sexual selection is the driving force behind the origin and diversification of sex chromosomes such as XX/XY and ZZ/ZW. However, chromosome mobility, mainly in fishes, may result in the formation of chromosomes of recent origin, a process known as turnover. The family Gymnotidae, which is composed of the genera Electrophorus+Gymnotus, presents a multiple system of the type X1X1X2X2/X1X2Y, which has been described for Gymnotus pantanal. This article describes the karyotype of three Amazon Gymnotus species, revealing the presence of both simple and multiple systems: Gymnotus carapo "Catalão" 2n=40 XX/XY, Gymnotus coropinae 2n=49♂/50♀ X1X1X2X2/X1X2Y, and Gymnotus sp. "Negro" 2n=50 XX/XY. Our hypothesis is that the simple system present in G. carapo "Catalão" is ancestral in relation to G. pantanal's multiple system and that the diversification of the subsequent multiple system occurred after the final separation of the Amazon and Paraná basins. Moreover, G. coropinae's multiple system may have originated from the simple system present in Gymnotus sp. "Negro." The distant position between the species in the Gymnotidae family's phylogeny in addition to differences in sex chromosome formula and number between Clade G1 G. coropinae and G. sp. "Negro" species and "Carapo" Clade. G. carapo and G. pantanal species suggest that both sequences of sexual systems occurred independently, supporting other proposed models and highlighting the fact that species of the genus Gymnotus may serve as a model for studying sex chromosome turnover.

Reviews in Fish Biology and Fisheries, 2011