Population structuration and chromosomal features homogeneity in Parodon nasus (Characiformes: Parodontidae): A comparison between Lower and Upper Paraná River representatives

The ichthyofauna of the La Plata hydrographic basin is divided into Upper and Lower Paraná River systems due to the geographic isolation of the Sete Quedas waterfalls, currently flooded by the lake of the Itaipu dam. In Parodontidae, pairs of species, or groups of cryptic species were described between these systems. Although genetic isolation and speciation have already been proposed in other species in the group, Parodon nasus has been maintained as a valid species and distributed throughout the La Plata river basin. In this perspective, specimens of P. nasus from four different sampling sites in the Upper and Lower Paraná River systems were compared regarding the karyotypes, molecular analyzes of population biology and species delimitation to investigate their genetic and population isolation in the La Plata river basin. Despite a geographic barrier and the immense geographic distance separating the specimens sampled from the Lower Paraná River system compared to those from the Upper Paraná River, the data obtained showed P. nasus as a unique taxon. Thus, unlike other species of Parodontidae that showed diversification when comparing the groups residing in the Lower versus Upper Paraná River, P. nasus showed a population structure and a karyotypic homogeneity.(AU)

A ictiofauna do sistema hidrográfico La Plata é dividida em alto e baixo rio Paraná devido ao isolamento geográfico dos Saltos das Sete Quedas há 22 milhões de anos, atualmente inundado pelo lago da represa da Usina de Itaipu. Em Parodontidae, espécies pares ou grupos de espécies crípticas foram descritos entre esses sistemas. Contudo, embora o isolamento genético e especiação já tenham sido propostos em outras espécies do grupo, Parodon nasus tem sido mantido como espécie válida e distribuída em toda a bacia do rio La Plata. Nessa perspectiva, exemplares de P. nasus de quatro diferentes pontos de amostragem nos sistemas do alto e baixo rio Paraná foram comparados quanto ao arranjo dos cariótipos, análises moleculares de biologia populacional e delimitação de espécies, afim de investigar seu isolamento genético e populacional na bacia do rio La Plata. Apesar da barreira geográfica e imensa distância geográfica separando os exemplares amostrados no sistema baixo rio Paraná em comparação àqueles do alto rio Paraná, os dados obtidos demonstraram P. nasus como único táxon válido. Dessa forma, diferentemente de outras espécies de Parodontidae que demonstraram diversificação quando comparados grupos pares residentes no baixo e alto rio Paraná, P. nasus demonstrou estruturação populacional e homogeneidade cariotípica.(AU)

Comparative cytogenetic analyses in Ancistrus species (Siluriformes: Loricariidae)

Ancistrus is a specious genus of armored catfishes that has been extensively used for cytogenetic studies in the last 17 years. A comparison of the extensive karyotypic plasticity within this genus is presented with new cytogenetic analysis for Ancistrus cf. multispinis and Ancistrus aguaboensis. This study aims to improve our understanding of chromosomal evolution associated with changes in the diploid number (2n) and the dispersion of ribosomal DNAs (rDNAs) within Ancistrus. Ancistrus cf. multispinis and A. aguaboensis exhibit 2n of 52 and 50 chromosomes, respectively. Given that A. cf. multispinis shares a 2n = 52 also found in Pterygoplichthyini, the sister group for Ancistrini, a Robertsonian (Rb) fusion event is proposed for the 2n reduction in A. aguaboensis. 5S rDNAs pseudogenes sites have already been associated with Rb fusion in Ancistrus and our analysis suggests that the 2n reduction in A. aguaboensis was triggered by double strand breaks (DSBs) and chromosomal rearrangements at 5S rDNA sites. The presence of evolutionary breakpoint regions (EBRs) into rDNA cluster is proposed to explain part of the Rb fusion in Ancistrus. Cytogenetic data presented extends the diversity already documented in Ancistrus to further understand the role of chromosomal rearrangements in the diversification of Ancistrini.(AU)

Ancistrus é um gênero rico em espécies de peixes conhecidos como cascudos e tem sido alvo de estudos citogenéticos nos últimos 17 anos. Uma comparação da plasticidade presente no gênero é apresentada com novas análises citogenéticas para Ancistrus cf. multispinis e Ancistrus aguaboensis. Este estudo visa melhorar nossa compreensão da evolução cromossômica associada as alterações do número diploide (2n) e a dispersão de DNAs ribossômicos (rDNAs) em Ancistrus. Ancistrus cf. multispinis e A. aguaboensis apresentaram 2n de 52 e 50 cromossomos, respectivamente. Visto que A. cf. multispinis compartilha 2n = 52 também encontrado em Pterygoplichthyini, o grupo irmão para Ancistrini, um evento de fusão Robertsoniana (Rb) é proposto para a redução do 2n em A. aguaboensis. Sítios de pseudogenes de rDNA 5S já foram associados a eventos de fusão Rb em Ancistrus e nossas análises sugerem que a redução do 2n em A. aguaboensis foi desencadeada por quebras na dupla fita e rearranjos cromossômicos em sítios de rDNA 5S. A presença de evolutionary breakpoint regions (EBRs) em clusters de rDNA foi proposta para explicar parte da fusão Rb em Ancistrus. Os dados citogenéticos apresentados ampliam a diversidade já documentada em Ancistrus visando melhor entender o papel dos rearranjos cromossômicos na diversificação de Ancistrini.(AU)

Chromosomal distribution of the retroelements Rex 1, Rex 3 and Rex 6 in species of the genus Harttia and Hypostomus (Siluriformes: Loricariidae)

The transposable elements (TE) have been widely applied as physical chromosome markers. However, in Loricariidae there are few physical mapping analyses of these elements. Considering the importance of transposable elements for chromosomal evolution and genome organization, this study conducted the physical chromosome mapping of retroelements (RTEs) Rex1, Rex3 and Rex6 in seven species of the genus Harttia and four species of the genus Hypostomus, aiming to better understand the organization and dynamics of genomes of Loricariidae species. The results showed an intense accumulation of RTEs Rex1, Rex3 and Rex6 and dispersed distribution in heterochromatic and euchromatic regions in the genomes of the species studied here. The presence of retroelements in some chromosomal regions suggests their participation in various chromosomal rearrangements. In addition, the intense accumulation of three retroelements in all species of Harttia and Hypostomus, especially in euchromatic regions, can indicate the participation of these elements in the diversification and evolution of these species through the molecular domestication by genomes of hosts, with these sequences being a co-option for new functions.(AU)

Os elementos transponíveis (TE) têm sido amplamente aplicados como marcadores cromossômicos. Contudo, em Loricariidae, há poucas análises de mapeamento físico destes elementos. Considerando a importância de elementos transponíveis para a evolução cromossômica e organização genômica, este trabalho realizou o mapeamento físico cromossômico dos retroelementos (RTEs) Rex1, Rex3 e Rex6 em sete espécies do gênero Harttia e em quatro espécies do gênero Hypostomus, com o intuito de melhor compreender a organização e dinâmica dos genomas das espécies de Loricariidae. Os resultados evidenciaram um intenso acúmulo dos RTEs Rex1, Rex3 e Rex6 e distribuição dispersa em regiões heterocromáticas e eucromáticas no genoma das espécies estudadas. A presença de retroelementos em algumas regiões cromossômicas sugere sua participação em vários rearranjos cromossômicos. Além disso, o intenso acúmulo dos três retroelementos em todas as espécies de Harttia e Hypostomus, especialmente em regiões eucromáticas, pode indicar a participação destes elementos na diversificação e evolução destas espécies através da domesticação molecular pelo genoma dos hospedeiros, com estas sequências sendo co-optadas paras novas funções.(AU)

Chromosome Mapping and Molecular Characterization of the Tc1/Mariner Element in Rineloricaria (Siluriformes: Loricariidae)

ABSTRACT The Tc1/Mariner sequence was isolated and mapped on chromosomes aiming to verify the association of this transposable element (TE) and chromosomal rearrangements in Rineloricaria. Cytogenetic analysis showed that Tc1/Mariner does not co-localize with chromosomal fusion points, in addition the analysis revealed intense molecular degeneration in its DNA sequence.

Comparative Cytogenetics Among Three Sympatric Hypostomus Species (Siluriformes: Loricariidae): An Evolutionary Analysis in a High Endemic Region

ABSTRACT The karyotypes of three armored catfish species (Loricariidae) from the Iguaçu river, southern of the Brazil, were compared using different techniques: C-banding, Ag-NOR and fluorescence in situ hybridization (FISH), which used 5S and 18S rDNAs and total Cot-1 fraction as probes. Hypostomus commersoni and Hypostomus derbyi presented 2n = 68 chromosomes, with karyotype formulae 12m+12sm+14st+30a and 12m+12sm+10st+34a, respectively; whereas Hypostomus myersi presented 2n = 74 chromosomes and 12m+16sm+12st+34a. The chromosomal localization of the Ag-NORs, 5S and 18S rDNAs differed in number of sites and chromosomal localization among the studied species. The total Cot-1 probe permitted the visualization of the repetitive DNA fraction in karyotypes of each species. Cross-hybridizations using total Cot-1 probe revealed that these species have repetitive DNAs in common. However, this does not occur in H. commersoni in relation to the other species. The apparent karyotype similarity suggests a close relationship between the sympatric H. commersoni and H. derbyi species, but the small differences detected in the examined chromosomal markers indicate evolutionary divergence due to gene flow restriction among them. Hence, the present findings indicate different composition of repetitive sequences among studied species, which permit to infer its role in chromosomal differentiation of Hypostomus.

Karyotype analysis of three species of Corydoras (Siluriformes: Callichthyidae) from southern Brazil: rearranged karyotypes and cytotaxonomy

The genus Corydoras comprises a diversity of species with different diploid numbers. We compared cytogenetic data among Corydoras species from different rivers of the Ponta Grossa Arch region in southern Brazil. Corydoras ehrhardti and C. aff. paleatus have a similar karyotype formula and the same diploid number (2n = 44). Corydoras lacrimostigmata has a higher diploid number, with 2n = 58 chromosomes. Fluorescence in situ hybridization using 5S and 18S ribosomal DNA probes suggests that these ribosomal DNA sequences are involved in chromosomal rearrangements in these Corydoras species. 5S rDNA is a chromosomal marker that is considered to be unique to the species analyzed in this study. Signals of interstitial telomeric sites are seen in a chromosome pair of C. lacrimostigmata, suggesting chromosomal rearrangements via fusions or translocations. This study revealed that C. ehrhardti and C. aff. paleatus have exclusive chromosomal markers associated with chromosome differentiation, which we speculate to prevent genetic introgression.(AU)

Corydoras compreende um gênero diversificado com espécies de diferentes números diploides. Nós comparamos dados citogenéticos de espécies de Corydoras de diferentes rios da região do Arco de Ponta Grossa no sul do Brasil. Corydoras ehrhardti e C. aff. paleatus tem fórmula cariotípica similar e o mesmo número diploide (2n = 44). Corydoras lacrimostigmata tem um número diploide maior, com 2n= 58 cromossomos. A hibridação in situ fluorescente (FISH) com sondas de DNA ribossomal 5S e 18S sugere que estas sequências de DNA ribossomal estão envolvidas em rearranjos cromossômicos nestas espécies de Corydoras. A marcação do DNAr 5S foi considerada espécie-específico para as espécies analisadas neste estudo. Sinais de sítios teloméricos intersticiais foram vistos em um par de cromossomos de C. lacrimostigmata sugerindo a ocorrência de rearranjos cromossômicos como fusões ou translocações. Este estudo revelou que as espécies C. ehrhardti e C. aff. paleatus têm marcadores cromossômicos exclusivos associados à diferenciação cromossômica, os quais, em nossa hipótese, podem prevenir a introgressão gênica.(AU)

Swim training and the genetic expression of adipokines in monosodium glutamate-treated obese rats

Objective The aim of this study was to evaluate the genetic expression of adipokines in the adipocytes of monosodium glutamate (MSG)-treated obese rats submitted to physical activity.Materials and methods Obesity was induced by neonatal MSG administration. Exercised rats (MSG and control) were subjected to swim training for 30 min for 10 weeks, whereas their respective controls remained sedentary. Total RNA was obtained from sections of the mesenteric adipose tissue of the rats. mRNA levels of adiponectin (Adipoq), tumor necrosis factor alpha (Tnf), peroxisome proliferator-activated receptor alpha (Ppara), and peroxisome proliferator-activated receptor gamma (Pparg) adipokines were quantified by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR).Results In the exercise-trained control group, the expression of Adipoq increased compared to the sedentary control, which was not observed in the MSG-obese rats. Increased levels of Tnf in MSG-obese rats were not reversed by the swim training. The expression of Ppara was higher in sedentary MSG-obese rats compared to the sedentary control. Swimming increased this adipokine expression in the exercise-trained control rats compared to the sedentary ones. mRNA levels of Pparg were higher in the sedentary MSG-rats compared to the sedentary control; however, the exercise did not influenced its expression in the groups analyzed.Conclusions In conclusion, regular physical activity was not capable to correct the expression of proinflammatory adipokines in MSG-obese rat adipocytes.

Hipertensão arterial de difícil controle e o polimorfismo A1166C do gene AT1 / Difficult-to-treat hypertension and AT1 A1166C gene polymorphism

Fundamentos: Polimorfismos presentes em genes que codificam proteínas do sistema renina-angiotensina aldosterona (SRAA) estão associados com o quadro de hipertensão arterial sistêmica (HAS) em algumas populações. Estudos demonstram a relação entre o polimorfismo A1166C no gene do receptor tipo 1 da angiotensina II (AT1) com a HAS, mas os dados ainda são controversos. Objetivo: Analisar a presença deste polimorfismo em pacientes portadores de HAS resistente da região dos Campos Gerais (PR), Brasil. Materiais e Métodos: Grupos de pacientes com hipertensão de fácil (G1) (n = 34) e difícil controle medicamentoso (G2) (n = 39) foram analisados quanto ao polimorfismo mencionado, utilizando-se a técnica de Polymerase Chain Reaction­ Restriction Fragment Lenght Polymorphism (PCR-RFLP). Os pacientes foram categorizados em três genótipos: AA, AC e CC. As frequências alélicas e genotípicas foram calculadas para cada grupo e os dados confrontados com as características metabólicas e antropométricas dos indivíduos. Resultados: não houve diferença entre os grupos quanto a sexo e idade. O índice de massa corporal (IMC), pressão arterial sistólica (PAS), diastólica (PAD) e número de anti-hipertensivos utilizados foram maiores no G2. Asfrequências alélicas e genotípicas mostraram-se semelhantes entre os grupos (p > 0,05). Conclusão: Nesta população, este polimorfismo não está associado ao fácil ou difícil controle da pressão arterial (PA). Possivelmente, outros fatores devem estar influenciando a HAS nestes pacientes

Background: Polymorphisms in genes encoding proteins of the renin-angiotensin-aldosterone system (RAAS) are associated with systemic arterial hypertension (SAH) in some populations. Some reports demonstrated the relationship between the angiotensin II type 1 receptor (AT1) A1166C gene polymorphism with SAH, but the data are still controversial. Objective: To analyze the presence of this polymorphism in patients porting difficult-to-treat SAH from Campos Gerais region (PR), Brazil. Materials and Methods: Groups of patients porting hypertension easy (G1) (n = 34) and difficult-to-treat using drugs (G2) (n = 39) were analyzed according to the polymorphism mentioned, using the Polymerase Chain Reaction­ Restriction Fragment Lenght Polymorphism (PCR-RFLP) technique. The patients were categorized into three genotypes: AA, AC and CC. The allele and genotype frequencies were calculated and the results were compared with metabolic and anthropometric characteristics of the patients. Results: There was no difference between groups regarding gender and age. The body mass index (BMI), systolic and diastolic blood pressures and the number of antihypertensive drugs were higher in G2. The allele and genotype frequencies were similar between the groups (p > 0.05). Conclusions: In this population, the polymorphism analyzed is not associated with easy or difficult-to-treat SAH. Possibly, other factors are influencing the hypertension in these patients

Evidence of incipient speciation in astyanax scabripinnis species complex (teleostei: characidae)

Two populations of the Astyanax scabripinnis complex, isolated by a waterfall with over 100 meters depth and inhabiting different altitudes of the same river (1850 m a.s.l. and 662 m a.s.l.) were compared in reproductive data, geometric morphometry, tooth morphology, anal-fin rays counts, and karyotype, in order to test the hypothesis of speciation between the two populations. The results in the geometric morphometry analysis showed differences between the populations. Discriminant function analysis (DFA) and canonical variance analysis revealed sexual dimorphism. Secondary sexual characters, such as hooks in the anal fin rays of the males are absent in the lower altitude population. Both populations had the same macro karyotype structure, except for the absence of B chromosomes in the lower altitude population. The fluorescence in situ hybridization showed differences for both markers (18S rDNA and 5S rDNA), and reproductive data suggests pre-zygotic reproductive isolation among the two populations. The data showed the absence of gene flow, indicating that an incipient speciation process has occurred, which leads the two populations to follow independent evolutionary pathways.

Duas populações do complexo Astyanax scabripinnis isoladas por uma queda d´água de mais de 100 metros de altura e localizadas em diferentes altitudes do mesmo rio (662 m e 1850 m a.s.l.) foram comparadas através de dados de reprodução, cariótipo, morfometria geométrica, morfologia dentária, e número de raios da nadadeira anal, de modo a testar a hipótese de especiação entre as duas populações. Os resultados de morfometria geométrica mostraram diferenças entre as populações. A análise da função discriminante (DFA) e a análise de variância canônica (CVA) demonstraram a presença de dimorfismo sexual. Caracteres sexuais secundários, como ganchos em raios da nadadeira anal dos machos, estão ausentes na população de menor altitude. Ambas as populações têm a mesma macro estrutura cariotípica, exceto pela ausência de cromossomos B na população de menor altitude. A hibridação in situ mostrou diferenças para ambos os marcadores (rDNA 18S e rDNA 5S), e os dados de reprodução sugerem isolamento reprodutivo pré-zigótico entre as duas populações. Os dados mostram ausência de fluxo gênico, indicando que ocorreu um processo de especiação incipiente, o que leva as duas populações seguirem vias evolutivas independentes.

Relação do polimorfismo C825T do gene GNB3 e hipertensão arterial sistêmica de difícil controle / Relationship between C825T polymorphism of the GNB3 gene and dificult-to-treat hypertension

Fundamentos: O polimorfismo C825T do gene GNB3 está associado à hipertensão arterial sistêmica (HAS) em algumas populações já analisadas, porém alguns estudos se mostram controversos no que se refere a esta relação. Objetivo: Avaliar a relação do polimorfismo C825T do gene GNB3 com a HAS de difícil controle medicamentoso em hipertensos de Campos Gerais, PR - Brasil. Métodos: Em relação ao polimorfismo C825T de GNB3, foram determinados os genótipos de 60 hipertensos, os quais foram estratificados em dois grupos (fácil e difícil controle medicamentoso), por meio da técnica de PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Lenght Polymorphism). Foram avaliadas as frequências alélicas e genotípicas, utilizando-se o teste do qui-quadrado de Pearson, com correção de Yates e odds ratio (OR). Resultados: Não houve diferenças entre os grupos, quando comparadas as frequências alélicas e genotípicas, indicando que a população está em equilíbrio. A probabilidade de o paciente possuir o polimorfismo e a HAS de difícil controle foi 53,5 % (OR=1,15; IC95 % = 0,41-3,26), analisando-se os genótipos. Já a análise dos alelos, separadamente, mostrou uma associação de 55,4 % (OR=1,24; IC95 % = 0,59-2,57). Conclusão: Nesta população não foi encontrada relação entre o polimorfismo C825T do gene GNB3 e a HAS de difícil controle, indicando que outros fatores estão influenciando a manifestação dessa doença nestes pacientes.

Background: C825T polymorphism of the GNB3 gene is associated with systemic arterial hypertension (SAH) in some studied populations, although certain studies are controversial in terms of this relationship. Objective: To evaluate the relationship between C825T polymorphism of the GNB3 gene and difficult-to-treat SAH among hypertensive patients in Campos Gerais, Paraná State, Brazil. Methods: With regard to C825T polymorphism of the GNB3 gene, the genotypes were defined for sixty hypertensive patients divided in 2 groups (easy and difficult-to-treat with drugs), using the Polymerase Chain Reaction - Restriction Fragment Length Polymorphism (PCR-RFLP) technique. The allele and genotype frequencies were assessed through the Pearson chi-square test, with Yates correction and odds ratio (OR). Results: There were no differences between the groups when comparing the allele and genotype frequencies, indicating that the population is in equilibrium. The probability that a patient has polymorphism with difficult-to-treat SAH reached 53.5% (OR=1.15, 95%CI = 0.41-3.26), analyzing the genotypes. A separate allele analysis showed an association of 55.4% (OR=1.24, 95%CI = 0.59-2.57). Conclusion: No relationship was found in this population between C825T polymorphism of the GNB3 gene and difficult-to-treat SAH, indicating that other factors are influencing the appearance of this disease among these patients.

Metabolic effects of an entero-omentectomy in mildly obese type 2 diabetes mellitus patients after three years

BACKGROUND: Various digestive tract procedures effectively improve metabolic syndrome, especially the control of type 2 diabetes mellitus. Very good metabolic results have been shown with vertical gastrectomy and entero-omentectomy; however, the metabolic effects of an isolated entero-omentectomy have not been previously studied. METHODS: Nine patients with type 2 diabetes mellitus and a body mass index ranging from 29 to 34.8 kg/m² underwent an entero-omentectomy procedure that consisted of an enterectomy of the middle jejunum and exeresis of the major part of the omentum performed through a mini-laparotomy. Glucagon-like peptide-1 and peptide YY were measured preoperatively and three months following the operation. Fasting and postprandial variations in glycemia, insulinemia, triglyceridemia, hemoglobin A1c, and body mass index were determined in the preoperative period and 3, 18 and, 36 months after the operation. RESULTS: All patients significantly improved the control of their type 2 diabetes mellitus. Postprandial secretion of peptide YY and Glucagon-like peptide-1 were enhanced, whereas hemoglobin A1c, fasting and postprandial glucose, insulin, and triglyceride levels were significantly reduced. Mean body mass index was reduced from 31.1 to 27.3 kg/m². No major surgical or nutritional complications occurred. CONCLUSIONS: Entero-omentectomy is easy and safe to perform. A simple reduction in jejunal extension and visceral fat causes important improvements in the metabolic profile.

Cytogenetic analysis of Astylus antis (Perty, 1830) (Coleoptera, Melyridae): Karyotype, heterochromatin and location of ribosomal genes

Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid number 2n = 18, with mostly metacentric chromosomes. Metaphase I cells exhibited 2n = 8II+Xyp and a parachute configuration of the sex chromosomes. Spermatogonial metaphase cells submitted to C-banding showed the presence of small dots of constitutive heterochromatin in the centromeric regions of nearly all the autosomes and on the short arm of the X chromosome (Xp), as well as an additional band on one of the arms of pair 1. Mitotic cells submitted to double staining with base-specific fluorochromes (DAPI-CMA3) revealed no regions rich in A+T or G+C sequences. Analysis of spermatogonial mitotic cells after sequential Giemsa/AgNO3 staining did not reveal any specific mark on the chromosomes. Meiotic metaphase I cells stained with silver nitrate revealed a strong impregnation associated to the sex chromosomes, and in situ hybridization with an 18S rDNA probe showed ribosomal cistrons in an autosomal bivalent.