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1.
Braz J Biol ; 83: e250003, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34669803

RESUMO

This study estimated the length-weight relationships of 16 fish species occurring close to the shores of sandy beaches along the lower Negro River basin, Brazilian Amazon. The specimens were captured for one day each month, in October to November 2016, early in the morning and early evening, using trawl net (20 m taken for standard length (SL - 0.1 cm precision) and total weight (TW - 0.01 g precision). The parameters a and b of the equation WT = a.LTb were estimated. The a values ranged from 0.0018 to 0.0226 and b values ranged from 2.5271 to 3.3244. This study also provides new data on of maximum lengths for six species, Amazonsprattus scintilla, Brycon pesu, Moenkhausia megalops, Pachyurus paucirastrus, Reganella depressa and Trachydoras microstomus, and new reports of the LWRs parameters of 15 fish species.


Assuntos
Characidae , Caraciformes , Perciformes , Animais , Brasil , Rios
2.
Braz J Biol ; 83: e249158, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34550290

RESUMO

The knowledge of the testicular and ovarian morphology of a particular fish species is of paramount importance. Such analyze enables the development of studies and techniques aiming the improvement of their reproduction, management, commercialization and even their conservation. This study performed the ovarian and testicular characterization of the ornamental Amazon fish Serrapinnus kriegi. A total of three males and three females had their gonads analyzed by optical microscopy. Females present ovaries filled with oocytes in asynchronous development, indicating partial spawning in the species. Moreover, the micropyle and micropilar cell formation was observed in primary growing oocytes, representing a precocious oocyte development; and the zona radiata in the final vitellogenic oocytes is thicker than other related species, evidencing the development of a better protection to the embryos in function of the waters' turbulence that characterize it spawning sites in the Amazonian streams. The male specimens' present anastomosed tubular testes with unrestricted spermatogonia spread along the entire seminiferous tubules. The present data elucidate the dynamic of spermatogenesis and oogenesis of an ornamental Amazonian species, through the description of the male and female germ cells development.


Assuntos
Characidae , Animais , Feminino , Gônadas , Masculino , Oócitos , Oogênese , Ovário , Testículo
3.
Elife ; 102021 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-34542411

RESUMO

Social behavior is a hallmark of complex animal systems; however, some species appear to have secondarily lost this social ability. In these non-social species, whether social abilities are permanently lost or suppressed is unclear. The blind cavefish Astyanax mexicanus is known to be asocial. Here, we reveal that cavefish exhibited social-like interactions in familiar environments but suppressed these interactions in stress-associated unfamiliar environments. Furthermore, the level of suppression in sociality was positively correlated with that of stereotypic repetitive behavior, as seen in mammals. Treatment with a human antipsychotic drug targeting the dopaminergic system induced social-like interactions in cavefish, even in unfamiliar environments, while reducing repetitive behavior. Overall, these results suggest that the antagonistic association between repetitive and social-like behaviors is deeply shared from teleosts through mammals.


Assuntos
Comportamento Animal , Characidae/fisiologia , Comportamento Social , Comportamento Estereotipado , Animais , Antipsicóticos/farmacologia , Aripiprazol/farmacologia , Comportamento Animal/efeitos dos fármacos , Cegueira , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Antagonistas dos Receptores de Dopamina D2/farmacologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/fisiologia , Ecossistema , Sistema da Linha Lateral/fisiologia , Mecanorreceptores/fisiologia , Mecanotransdução Celular , Reconhecimento Psicológico , Comportamento Estereotipado/efeitos dos fármacos , Natação , Fatores de Tempo , Gravação em Vídeo
4.
Cytogenet Genome Res ; 161(5): 249-256, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34433167

RESUMO

B chromosomes occur in different species of the small characid fishes of the genus Moenkhausia. These supernumerary elements, that do not recombine with chromosomes of the standard A complement and follow their own evolutionary mechanism vary in number, morphology, and distribution. Here, we show karyotypic data of individuals of 2 populations of Moenkhausia oligolepis of the Brazilian Amazon (Pedro Correia and Taboquinha streams, Tocantins river basin), both with a diploid number of 50 chromosomes and karyotypic formula of 10m + 32sm + 8a. In addition to the normal complement, we also observed the occurrence of B chromosomes in the 2 populations with intra- and interindividual variation ranging from 0 to 10 Bs, independent of sex. The C-banding pattern evidenced heterochromatic blocks located mainly in the pericentromeric region of the chromosomes, while the B chromosomes appeared euchromatic. Silver-stained nucleolus organizer regions were identified in multiples sites, and some of these blocks were positive when stained with chromomycin A3. The karyotype analysis and the application of whole-chromosome painting in populations of M. oligolepis reinforce the conservation of the basal diploid number for the genus, as well as the evolutionary tendency in these fishes to carry B chromosomes. Both populations turned out to be in different stages of stability and expansion of their B chromosomes. We further suggest that the origin of these chromosomes is due to the formation of isochromosomes. Here, we identified a pair of complement A chromosomes involved in this process.


Assuntos
Characidae/genética , Instabilidade Cromossômica , Cromossomos/química , Cariotipagem/métodos , Animais , Brasil , Cromomicina A3/química , Bandeamento Cromossômico , Mapeamento Cromossômico , Feminino , Corantes Fluorescentes/química , Hibridização in Situ Fluorescente , Cariótipo , Masculino , Mitose , Ploidias
5.
Environ Toxicol Pharmacol ; 87: 103727, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34454063

RESUMO

The intensive use of the antihypertensive losartan potassium (LOS) has culminated in its high occurrence in aquatic environments. However, insufficient studies had investigated its effects in non-target organisms. In this study, ecotoxicity of LOS was assessed in aquatic organisms from distinct trophic levels (Desmodesmus subspicatus, Daphnia magna, and Astyanax altiparanae). Genotoxicity was assessed by the comet assay in D. magna and A. altiparanae, and biochemical biomarkers for the fish. LOS was more toxic to D. subspicatus (EC50(72h) = 27.93 mg L-1) than D. magna (EC50 = 303.69 mg L-1). Subsequently, this drug showed to induce more DNA damage in D. magna than A. altiparanae, when exposed to 2.5 mg L-1. No significant stress responses were observed by the fish biomarkers, suggesting that higher trophic levels organisms are more tolerant to LOS toxicity. LOS showed relatively low toxic potential for a short period of exposure, but with different patterns of toxicity for the organisms from distinct trophic levels, contributing to further risk assessment of LOS.


Assuntos
Anti-Hipertensivos/toxicidade , Losartan/toxicidade , Poluentes Químicos da Água/toxicidade , Acetilcolinesterase/metabolismo , Animais , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/genética , Organismos Aquáticos/crescimento & desenvolvimento , Organismos Aquáticos/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Characidae/genética , Characidae/metabolismo , Clorofíceas/efeitos dos fármacos , Clorofíceas/crescimento & desenvolvimento , Ensaio Cometa , Daphnia/efeitos dos fármacos , Daphnia/genética , Cadeia Alimentar , Glutationa/metabolismo , Glutationa Transferase/metabolismo , Músculos/efeitos dos fármacos , Músculos/metabolismo
6.
J Fish Biol ; 99(5): 1719-1728, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34392530

RESUMO

Individuals of the same species may present different reproductive tactics depending on the environment in which they develop and mature. The present study aimed to define the gonadal development phases of males and females of Astyanax rivularis and to carry out a comparative analysis of the reproductive development of specimens captured in two isolated environments of the São Francisco River basin in Serra da Canastra, Brazil (Point 1: low vegetation and river showing calm and crystalline waters with small well formations; Point 2: current waters, and well-established areas of arboreal vegetation). Thus, the gonads of A. rivularis specimens were collected, fixed and processed with techniques for light microscopy. Five maturation phases of the females' reproductive cycle were established: immature, developing, spawning capable, regressing and regenerating. Three maturation phases of the males' reproductive cycle were observed: spawning capable, regressing, and regenerating. There are differences in the phases of gonadal development of A. rivularis between the two sampling points so that, possibly, animals upstream of the waterfall demonstrate a delay in the reproductive cycle in relation to animals downstream.


Assuntos
Characidae , Animais , Brasil , Feminino , Gônadas , Masculino , Reprodução , Rios
7.
PLoS One ; 16(8): e0249439, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34437552

RESUMO

We demonstrate that simple, non-invasive environmental DNA (eDNA) methods can detect transgenes of genetically modified (GM) animals from terrestrial and aquatic sources in invertebrate and vertebrate systems. We detected transgenic fragments between 82-234 bp through targeted PCR amplification of environmental DNA extracted from food media of GM fruit flies (Drosophila melanogaster), feces, urine, and saliva of GM laboratory mice (Mus musculus), and aquarium water of GM tetra fish (Gymnocorymbus ternetzi). With rapidly growing accessibility of genome-editing technologies such as CRISPR, the prevalence and diversity of GM animals will increase dramatically. GM animals have already been released into the wild with more releases planned in the future. eDNA methods have the potential to address the critical need for sensitive, accurate, and cost-effective detection and monitoring of GM animals and their transgenes in nature.


Assuntos
Animais Geneticamente Modificados/genética , DNA Ambiental/genética , Transgenes/genética , Animais , Characidae/genética , Drosophila melanogaster/genética , Monitoramento Ambiental/métodos , Camundongos/genética
8.
An Acad Bras Cienc ; 93(2): e20190565, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34259790

RESUMO

The aging process of reservoirs has been extensively investigated; however, little is known about how fish populations are adjusted after many years of impoundment. Thus, this study aimed to compare the diet, length-weight relationship, sizes classes, variation in size, and age of Astyanax lacustris Lütken, 1875 collected from lotic and lentic habitats of an aging reservoir. The study group consisted of 730 captured fishes. We found that specimens collected from lotic habitats had a wider range of size classes (1.0 to 12.0 cm), were linked to a high frequency of juveniles (48.7%), and had greater feeding activity (higher stomach fullness). In contrast, fishes collected from lentic environments exhibited high rates of capture (78.4%), increased frequency of adults (87.3%), and higher values of mean standard length. The length-weight relationship indicated that lentic fishes were heavier than fish collected from lotic areas. Moreover, we observed 37 food items in A. lacustris diet, mainly plant material, algae, Cladocera, Hymenoptera, Coleoptera, and Ephemeroptera. Differences among the diet of fishes between sites were evidenced with Permanova (p < 0.05). Astyanax lacustris can be considered a persistent species in Chavantes Reservoir after aging, encountering conditions to complete its life span and adjusting to food resources.


Assuntos
Characidae , Caraciformes , Animais , Biologia , Dieta , Ecossistema , Peixes , Rios
9.
J Fish Biol ; 99(4): 1380-1392, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34259347

RESUMO

In this study, a new species of Moenkhausia is described from the upper rio Juruena, rio Tapajós basin, Brazil. It is distinguished from all congeners by the presence of minute bony hooks in all fins of both mature females and males and combination of a prepelvic region flattened, dorsal portion of the humeral blotch extending two scales horizontally and vertically, lateral line with 28-32 scales, five scale series above and below lateral line; circumpeduncular scales 13-14, anal-fin rays 16-19 and dorsal portion of eyes blue in live specimens. The new species is also supported by high divergence in the mitochondrial gene cytochrome c oxidase subunit I (COI). The presence of minute fin bony hooks in both females and males, population variations and late development of the lateral line in Moenkhausia andrica are discussed.


Assuntos
Characidae , Caraciformes , Nadadeiras de Animais , Animais , Brasil , Characidae/genética , Caraciformes/genética , Feminino , Masculino , Rios
10.
Artigo em Inglês | MEDLINE | ID: mdl-34319218

RESUMO

Environmental impacts on water resources and discharges of pollutants are some of the main problems of aquatic ecosystems. Currently, the Iguaçu River is considered the second most polluted river in Brazil, therefore, given the importance of understanding the effects of water pollution on living organisms, this study aimed to analyze the possible genotoxic effects in Astyanax bifasciatus (Characiformes; Characidae) and Geophagus brasiliensis (Perciformes: Cichlidae) in response to the water quality of the Iguaçu River. Four sampling points were determined on the Iguaçu River, with different levels of environmental impact. The micronuclei and nuclear abnormalities were quantified by counting 2000 erythrocytes from each specimen. There was a statistical difference in the frequency of nuclear abnormalities both for A. bifasciatus (Kruskal-Wallis 3;30 = 10.9; p = 0.01) and for G. brasiliensis (Kruskal-Wallis 3;26 = 12.27; p = 0.006), with point 1 (critically degraded) showing a higher frequency of nuclear abnormalities and point 4 (moderately degraded) showing a lower frequency of nuclear abnormalities for both species, showing genotoxic potential in fish erythrocytes. This result demonstrates the need for further discussion on the conservation of the Iguaçu River as well as broadening the discussion on its potability.


Assuntos
Characidae , Poluentes Químicos da Água , Animais , Brasil , Characidae/genética , Dano ao DNA , Ecossistema , Monitoramento Ambiental , Rios , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
11.
PLoS Genet ; 17(7): e1009642, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34252077

RESUMO

Circadian rhythms are nearly ubiquitous throughout nature, suggesting they are critical for survival in diverse environments. Organisms inhabiting largely arrhythmic environments, such as caves, offer a unique opportunity to study the evolution of circadian rhythms in response to changing ecological pressures. Populations of the Mexican tetra, Astyanax mexicanus, have repeatedly invaded caves from surface rivers, where individuals must contend with perpetual darkness, reduced food availability, and limited fluctuations in daily environmental cues. To investigate the molecular basis for evolved changes in circadian rhythms, we investigated rhythmic transcription across multiple independently-evolved cavefish populations. Our findings reveal that evolution in a cave environment has led to the repeated disruption of the endogenous biological clock, and its entrainment by light. The circadian transcriptome shows widespread reductions and losses of rhythmic transcription and changes to the timing of the activation/repression of core-transcriptional clock. In addition to dysregulation of the core clock, we find that rhythmic transcription of the melatonin regulator aanat2 and melatonin rhythms are disrupted in cavefish under darkness. Mutants of aanat2 and core clock gene rorca disrupt diurnal regulation of sleep in A. mexicanus, phenocopying circadian modulation of sleep and activity phenotypes of cave populations. Together, these findings reveal multiple independent mechanisms for loss of circadian rhythms in cavefish populations and provide a platform for studying how evolved changes in the biological clock can contribute to variation in sleep and circadian behavior.


Assuntos
Evolução Biológica , Characidae/fisiologia , Relógios Circadianos/genética , Proteínas de Peixes/genética , Animais , Encéfalo/fisiologia , Cavernas , Characidae/genética , Relógios Circadianos/fisiologia , Evolução Molecular , Regulação da Expressão Gênica , Genética Populacional , Hibridização in Situ Fluorescente , Fígado/fisiologia , Melatonina/metabolismo , Mutação , Sono/genética , Sono/fisiologia
12.
Fish Physiol Biochem ; 47(4): 1165-1177, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34142328

RESUMO

The objective of this study was to analyze the sublethal effects of propiconazole on Deuterodon iguape, a native fish common in Brazil, which has potential for aquaculture and use as a bioindicator. The hypothesis was to test whether D. iguape has a metabolism similar to Danio rerio so that its use in bioassays may be validated. Lethal concentration (LC50) and metabolic rates were studied in fish exposed to propiconazole. Specific oxygen consumption and ammonia excretion for D. iguape and D. rerio increased by 0.01 µg L-1 and then decreased as the propiconazole concentration increased. The decrease in the averages of specific oxygen consumption at the concentration of 0.1 µg L-1 represented a reduction in the metabolic rate compared to the control of 71% for D. iguape and 40% D. rerio. For the ammonia excretion, at the same concentration, there was a reduction of 68.7% and 45.4% for D. iguape and D. rerio, respectively. When comparing ammonia excretion of the two species for each concentration of propiconazole, there was a significant difference (p < 0.05) in relation to the control and for the highest concentration (0.1 µg L-1). As for specific oxygen consumption, there was a statistically significant difference only for the concentration of 0.1 µg L-1. D. iguape proved to be a good and useful bioindicator for ichthyologists or ecologists in studies of moderate pesticide contamination in freshwater aquatic environments, as its metabolic response was similar to D. rerio.


Assuntos
Characidae/metabolismo , Fungicidas Industriais/toxicidade , Triazóis/toxicidade , Poluentes Químicos da Água/toxicidade , Amônia/metabolismo , Animais , Brasil , Dose Letal Mediana , Consumo de Oxigênio , Peixe-Zebra
13.
Microb Pathog ; 158: 104991, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34175434

RESUMO

The present study describes the morphological, histopathological and SSU rDNA data of a new myxosporean species infecting farmed Astyanax lacustris fish from the state of São Paulo, Brazil. Henneguya lambariensis sp. nov. was found infecting the gills, and the plasmodial development resulted in displacement, blood congestion, compression, deformation and lamellar fusion, stretching of the epithelia, hyperplasia of the epithelial cells, edema, and mild infiltration of the mast cells and lymphocytes. The SSU rDNA sequencing resulted in the sequencing of 1804 nucleotides that did not correspond to any myxosporean sequences deposited in GenBank. The closest phylogenetic affinity of the new species was to the South American Henneguya loreotoensis and Henneguya guanduensis, which also parasite the gills. The present study suggests this new myxosporean species has considerable pathogenic potential, and health monitoring should be implemented in A. lacustris fish farms to ensure production.


Assuntos
Characidae , Doenças dos Peixes , Myxozoa , Doenças Parasitárias em Animais , Animais , Brasil , Brânquias , Myxozoa/genética , Filogenia
14.
Braz J Biol ; 82: e232701, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34076161

RESUMO

The present study objectified to evaluate the trophic relationships and the possible aggressive mimicry involving Carnegiella strigata, Carnegiella marthae and Gnathocharax steindachneri, in lowland forest streams. Samplings occurred in November 2002, March and August 2003 in Amanã Sustainable Development Reserve (ASDR). The total of 943 fish was caught, being 79.43% of C. marthae, 3.18% of C. strigata and 17.39% of G. steindachneri. Stomach contents, degree of stomach repletion, relative volume and frequency of occurrence of food items were evaluated. Thirteen food items were identified, and the presence of terrestrial and aquatic insects indicates the high dependence of these species and the flooded forest. Low feeding overlap was observed between Carnegiella strigata and C. marthae compared to Gnathocharax steindachneri. However, the overlap between the two Carnegiella species was relatively high, which could explain the low frequency of syntopic occurrence among these species, suggesting a possible case of competitive exclusion.


Assuntos
Characidae , Caraciformes , Animais , Peixes , Conteúdo Gastrointestinal , Lagos , Rios
15.
Parasitol Int ; 84: 102406, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34144199

RESUMO

The present study describes three new species of monogenean parasites of characid fishes from the Upper Paraná River basin, Brazil: Characithecium paranapanemense n. sp. on Psalidodon paranae and Psalidodon bockmanni, Diaphorocleidus magnus n. sp. on Astyanax lacustris and Psalidodon fasciatus, and Diaphorocleidus neotropicalis n. sp. on Astyanax lacustris and P. bockmanni. An amendment for Diaphorocleidus is proposed, since additional characters observed in the new species required to extend the generic diagnostic features mainly to include: articulation process connecting the base of the MCO with accessory piece present or absent, and accessory piece with variable shapes (plate-like, pincer-shaped, wrench-shaped, sheath-shaped), divided or not into subunits. Characithecium paranapanemense n. sp. can be distinguished from other congeners by the morphology of its MCO and accessory piece. Diaphorocleidus magnus n. sp. differs from most of its congeners by the morphology of its accessory piece, the presence of articulation process connecting the base of the MCO with accessory piece, and the morphology of the sclerotized structures of the haptor. Diaphorocleidus neotropicalis n. sp. can be easily distinguished from its congeners by the morphology of the accessory piece, the sclerotized structures of the haptor and the morphology of the vagina. Molecular data of the new species (partial 28S rDNA and mitochondrial cytochrome oxidase I) were obtained and the first phylogenetic analysis based on 28S rDNA gene sequences for species of Characithecium and Diaphorocleidus are provided. Although Diaphorocleidus and Characithecium share some morphological similarities, phylogenetic analysis indicates that species of these two genera are not closely related.


Assuntos
Characidae , Doenças dos Peixes/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Brasil/epidemiologia , DNA de Helmintos/análise , DNA Ribossômico/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Proteínas de Helminto/análise , Masculino , Proteínas Mitocondriais/análise , Prevalência , Trematódeos/anatomia & histologia , Trematódeos/citologia , Trematódeos/genética , Infecções por Trematódeos/parasitologia
16.
Cells ; 10(5)2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064768

RESUMO

The way in which transcriptional activity overcomes the physical DNA structure and gene regulation mechanisms involves complex processes that are not yet fully understood. Modifications in the cytosine-guanine sequence of DNA by 5-mC are preferentially located in heterochromatic regions and are related to gene silencing. Herein, we investigate evidence of epigenetic regulation related to the B chromosome model and transposable elements in A. scabripinnis. Indirect immunofluorescence using anti-5-mC to mark methylated regions was employed along with quantitative ELISA to determine the total genomic DNA methylation level. 5-mC signals were dispersed in the chromosomes of both females and males, with preferential accumulation in the B chromosome. In addition to the heterochromatic methylated regions, our results suggest that methylation is associated with transposable elements (LINE and Tc1-Mariner). Heterochromatin content was measured based on the C-band length in relation to the size of chromosome 1. The B chromosome in A. scabripinnis comprises heterochromatin located in the pericentromeric region of both arms of this isochromosome. In this context, individuals with B chromosomes should have an increased heterochromatin content when compared to individuals that do not. Although, both heterochromatin content and genome methylation showed no significant differences between sexes or in relation to the occurrence of B chromosomes. Our evidence suggests that the B chromosome can have a compensation effect on the heterochromatin content and that methylation possibly operates to silence TEs in A. scabripinnis. This represents a sui generis compensation and gene activity buffering mechanism.


Assuntos
Characidae/metabolismo , Cromossomos/metabolismo , Citidina/análogos & derivados , Metilação de DNA , Elementos de DNA Transponíveis , Inativação Gênica , Heterocromatina/metabolismo , Animais , Citidina/farmacologia , Citogenética , Ensaio de Imunoadsorção Enzimática , Epigênese Genética , Feminino , Hibridização in Situ Fluorescente , Isocromossomos , Masculino , Metilação
17.
Fish Shellfish Immunol ; 116: 12-18, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33965526

RESUMO

Triploid induction is a promising biotechnique that could be used to enhance aquaculture yields in the near future. However, studies conducted with several fish species have demonstrated that the presence of an extra set of chromosomes may result in deleterious health effects. Furthermore, studies of fish immune responses still need to be conducted before these specimens can be readily commercialized. In the study presented herein, we evaluated the effects of triploid induction on hematology, erythrocyte morphometry and morphology, phagocytosis, and the expression levels of IL-1ß and TGF-ß using specimens of the Neotropical species, Astyanax altiparanae. In general, the cell counts of erythrocytes, leukocytes, and neutrophils in triploid fish were lower than those in diploid fish. The erythrocytes of triploid fish were larger than those found in diploid fish, but also demonstrated considerably higher frequencies of cellular and nuclear abnormalities. Although not statistically significant, triploid induction resulted in a phagocytic capacity (PC) 20% lower than that found with diploid fish. No notable differences were observed in phagocytic index (PI). Gene expression levels for the cytokine IL-1 were lower in tissues from the head kidney, liver, and spleen of triploid fish with respect to diploid fish. Gene expression levels of TGF-ß were lower only in the spleen of triploids compared to diploids. In conclusion, triploid induction resulted in A. altiparanae specimens with immune impairments and potentially lower resistances to disease and low-quality environments.


Assuntos
Characidae , Imunidade Inata , Triploidia , Animais , Characidae/sangue , Characidae/genética , Characidae/imunologia , Eritrócitos , Feminino , Proteínas de Peixes/genética , Testes Hematológicos , Interleucina-1beta/genética , Leucócitos/imunologia , Masculino , Fagocitose , Saccharomyces cerevisiae , Fator de Crescimento Transformador beta/genética
18.
BMC Ecol Evol ; 21(1): 94, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-34020589

RESUMO

BACKGROUND: Despite a longstanding interest in understanding how animals adapt to environments with limited nutrients, we have incomplete knowledge of the genetic basis of metabolic evolution. The Mexican tetra, Astyanax mexicanus, is a species of fish that consists of two morphotypes; eyeless cavefish that have adapted to a low-nutrient cave environment, and ancestral river-dwelling surface fish with abundant access to nutrients. Cavefish have evolved altered blood sugar regulation, starvation tolerance, increased fat accumulation, and superior body condition. To investigate the genetic basis of cavefish metabolic evolution we carried out a quantitative trait loci (QTL) analysis in surface/cave F2 hybrids. We genetically mapped seven metabolism-associated traits in hybrids that were challenged with a nutrient restricted diet. RESULTS: We found that female F2 hybrids are bigger than males and have a longer hindgut, bigger liver, and heavier gonad, even after correcting for fish size. Although there is no difference between male and female blood sugar level, we found that high blood sugar is associated with weight gain in females and lower body weight and fat level in males. We identified a significant QTL associated with 24-h-fasting blood glucose level with the same effect in males and females. Differently, we identified sex-independent and sex-dependent QTL associated with fish length, body condition, liver size, hindgut length, and gonad weight. We found that some of the genes within the metabolism QTL display evidence of non-neutral evolution and are likely to be under selection. Furthermore, we report predicted nonsynonymous changes to the cavefish coding sequence of these genes. CONCLUSIONS: Our study reveals previously unappreciated genomic regions associated with blood glucose regulation, body condition, gonad size, and internal organ morphology. In addition, we find an interaction between sex and metabolism-related traits in A. mexicanus. We reveal coding changes in genes that are likely under selection in the low-nutrient cave environment, leading to a better understanding of the genetic basis of metabolic evolution.


Assuntos
Characidae , Locos de Características Quantitativas , Animais , Evolução Biológica , Characidae/genética , Mapeamento Cromossômico , Feminino , Masculino , México , Locos de Características Quantitativas/genética
19.
Int J Biol Macromol ; 183: 1079-1086, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33984380

RESUMO

Generally, a teleostean group possesses only one type or a set of similar mitochondrial gene arrangements. However, a new type of gene arrangement has been identified in the mitochondrial genomes (mitogenomes) of Moenkhausia. Here, three newly sequenced complete mitogenomes of tetras (Characidae: Moenkhausia) are presented (M. costae, M. pittieri, and M. sanctaefilomenae). The three mitogenomes had a classical circular structure, with total lengths ranging from 15,811 to 18,435 bp. Base composition analysis indicated that the sequences were biased toward adenine (A) and thymine (T), with A + T content of 54.63% in M. costae, 58.47% in M. pittieri, and 59.98% in M. sanctaefilomenae. The gene order and organization of M. sanctaefilomenae differed from those of typical teleostean mitogenomes. The genes tRNA-Ile, tRNA-Gln, and tRNA-Pro were translocated between tRNA-Trp and tRNA-Asn. One extra tRNA-Met and an extra CR were also discovered in the mitogenome. BI and ML analyses based on sequences of 38 different mitogenomes showed that M. costae and M. pittieri were classified together, and M. sanctaefilomenae was slightly further from other fish of the same genus. These results provide insight into the gene arrangement features of Characidae mitogenomes and lay the foundation for further phylogenetic studies on Characidae.


Assuntos
Characidae/genética , Genoma Mitocondrial/genética , Animais , Ordem dos Genes/genética , Rearranjo Gênico/genética , RNA de Transferência/genética
20.
Sci Rep ; 11(1): 10312, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33986376

RESUMO

The direction of visceral organ asymmetry is highly conserved during vertebrate evolution with heart development biased to the left and pancreas and liver development restricted to opposing sides of the midline. Here we show that reversals in visceral organ asymmetry have evolved in Astyanax mexicanus, a teleost species with interfertile surface-dwelling (surface fish) and cave-dwelling (cavefish) forms. Visceral organ asymmetry is conventional in surface fish but some cavefish have evolved reversals in heart, liver, and pancreas development. Corresponding changes in the normally left-sided expression of the Nodal-Pitx2/Lefty signaling system are also present in the cavefish lateral plate mesoderm (LPM). The Nodal antagonists lefty1 (lft1) and lefty2 (lft2), which confine Nodal signaling to the left LPM, are expressed in most surface fish, however, lft2, but not lft1, expression is absent during somitogenesis of most cavefish. Despite this difference, multiple lines of evidence suggested that evolutionary changes in L-R patterning are controlled upstream of Nodal-Pitx2/Lefty signaling. Accordingly, reciprocal hybridization of cavefish and surface fish showed that modifications of heart asymmetry are present in hybrids derived from cavefish mothers but not from surface fish mothers. The results indicate that changes in visceral asymmetry during cavefish evolution are influenced by maternal genetic effects.


Assuntos
Padronização Corporal , Characidae/embriologia , Animais , Evolução Biológica , Feminino
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