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BACKGROUND: The field of bee genomics has considerably advanced in recent years, however, the most diverse group of honey producers on the planet, the stingless bees, are still largely neglected. In fact, only eleven of the ~ 600 described stingless bee species have been sequenced, and only three using a long-read (LR) sequencing technology. Here, we sequenced the nuclear and mitochondrial genomes of the most common, widespread and broadly reared stingless bee in Brazil and other neotropical countries-Tetragonisca angustula (popularly known in Brazil as jataí). RESULTS: A total of 48.01 Gb of DNA data were generated, including 2.31 Gb of Pacific Bioscience HiFi reads and 45.70 Gb of Illumina short reads (SRs). Our preferred assembly comprised 683 contigs encompassing 284.49 Mb, 62.84 Mb of which (22.09%) corresponded to 445,793 repetitive elements. N50, L50 and complete BUSCOs reached 1.02 Mb, 91 contigs and 97.1%, respectively. We predicted that the genome of T. angustula comprises 17,459 protein-coding genes and 4,108 non-coding RNAs. The mitogenome consisted of 17,410 bp, and all 37 genes were found to be on the positive strand, an unusual feature among bees. A phylogenomic analysis of 26 hymenopteran species revealed that six odorant receptor orthogroups of T. angustula were found to be experiencing rapid evolution, four of them undergoing significant contractions. CONCLUSIONS: Here, we provided the first nuclear and mitochondrial genome assemblies for the ecologically and economically important T. angustula, the fourth stingless bee species to be sequenced with LR technology thus far. We demonstrated that even relatively small amounts of LR data in combination with sufficient SR data can yield high-quality genome assemblies for bees.

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The increasing use of UV filters, such as benzophenone-3 (BP-3) and titanium dioxide nanoparticles (TiO2 NPs), has raised concerns regarding their ecotoxicological effects on the aquatic environment. The aim of the present study was to examine the embryo-larval toxicity attributed to BP-3 or TiO2 NPs, either alone or in a mixture, utilizing zebrafish (Danio rerio) as a model after exposure to environmentally relevant concentrations of these compounds. Zebrafish embryos were exposed to BP-3 (10, 100, or 1000 ng/L) or TiO2 NPs (1000 ng/L) alone or in a mixture (BP-3 10, 100, or 1000 ng/L plus 1000 ng/L of TiO2 NPs) under static conditions for 144 hr. After exposure, BP-3 levels were determined by high-performance liquid chromatography (HPLC). BP-3 levels increased in the presence of TiO2 NPs, indicating that the BP-3 degradation decreased in the presence of the NPs. In addition, in the presence of zebrafish, BP-3 levels in water decreased, indicating that zebrafish embryos and larvae might absorb BP-3. Data demonstrated that, in general, environmentally relevant concentrations of BP-3 and TiO2 NPs, either alone or in a mixture, did not significantly induce changes in heart and spontaneous contractions frequencies, levels of reactive oxygen species (ROS), morphological and morphometric parameters as well as mortality rates during 144 hr exposure. However, the groups exposed to TiO2 NPs alone and in a mixture with BP-3 at 10 ng/L exhibited an earlier significant hatching rate than the controls. Altogether, the data indicates that a potential ecotoxicological impact on the aquatic environment exists.

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INTRODUCTION: The prevalence of hepatitis C (HCV) is high among prisoners. If untreated, a substantial number of patients progress to cirrhosis, hepatocarcinoma, or liver failure. World Health Organization aims to reduce the incidence of infection by 90% by 2030. OBJECTIVE: To describe the prevalence of anti-HCV and sociodemographic and clinical aspects, related to the presence of the antibody, in the population deprived of liberty. METHODS: Cross-sectional and epidemiological survey, with exploratory, observational, quantitative-analytical components. A simple random sample of 233 participants, with 95% Confidence Interval (CI) and, a 4% margin of error, was calculated for a population of 1,564 prisoners. The relationship between sociodemographic and clinical variables was evaluated, considering as outcome of the rapid test for anti-HCV results, using the associative measure Prevalence Ratio (PR) with a 95% CI. RESULTS: 240 people participated. The prevalence of anti-HCV was 2%, and the use of injectable drugs (PR 14.75; PRIC95% 2.09-104.28), being born in the decades of 1951 to 1980 (PR 9.28; PRIC95% 1.06-81.57) and be co-infected with hepatitis B virus (PR 10.75; PRIC95% 1.66-69.65) were the aspects that presented a relevant prevalence ratio for the presence of the virus, which could be generalized to the population. CONCLUSION: This is a population that is difficult to access, the study is relevant because it contributes to preventive measures of public health in the prison system. Moreover, it shows the need to implement measures to prevent and contain the spread of HCV, aiming at the elimination of hepatitis C in this population.

INTRODUÇÃO: A prevalência da hepatite C (HCV) é elevada entre os prisioneiros. Se não tratada, proporção substancial das infecções progride para cirrose, hepatocarcinoma ou insuficiência hepática. Organização Mundial de Saúde tem a meta de reduzir a incidência da infecção em 90% até 2030. OBJETIVO: Descrever a prevalência do anti-HCV e os aspectos sociodemográficos e clínicos, relacionados à presença do anticorpo, na população privada de liberdade. MÉTODOS: Estudo transversal por inquérito epidemiológico, com componente exploratório, observacional, quantitativo-analítico. Foi calculada amostra aleatória simples de 233 pessoas, Intervalo de Confiança (IC) 95%, margem de erro 4% para população de 1564 prisioneiros. Foi avaliada a relação entre os aspectos sociodemográficos e clínicos com o desfecho obtido pelo teste rápido para anti-HCV por meio da medida associativa Razão de Prevalência (RP) e IC de 95% para essa estimativa. RESULTADOS: Participaram 240 pessoas. A prevalência do anti-HCV foi de 2%, sendo que o uso de drogas injetáveis (RP 14,75; RPIC95% 2,09-104,28), ter nascido nas décadas de 1951 a 1980 (RP 9,28; RPIC95% 1,06-81,57) e ser coinfectado com o vírus da hepatite B (RP 10,75; RPIC95% 1,66-69,65) foram os aspectos que apresentaram razão de prevalência para a presença do vírus, passível de generalização para a população. CONCLUSÃO: Trata-se de população de difícil acesso, o estudo é relevante por contribuir para medidas preventivas de saúde pública no sistema prisional. Outrossim, mostra a necessidade de se implementar medidas para evitar e conter a disseminação de HCV, visando a microeliminação da hepatite C na população carcerária.

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Eosinophil sombrero vesicles are large tubular carriers resident in the cytoplasm of human eosinophils, identifiable by transmission electron microscopy, and important for immune mediator transport. Increased formation of sombrero vesicles occurs in activated eosinophils in vitro and in vivo. In tissue sites of eosinophilic cytolytic inflammation, extracellular eosinophil sombrero vesicles are noted, but their frequency and significance in eosinophil-associated diseases remain unclear. Here, we performed comprehensive quantitative transmission electron microscopy analyses and electron tomography to investigate the numbers, density, integrity, and 3-dimensional structure of eosinophil sombrero vesicles in different biopsy tissues from 5 prototypic eosinophil-associated diseases (eosinophilic chronic rhinosinusitis/nasal sinuses, ulcerative colitis/intestines, hypereosinophilic syndrome/skin, dermatitis/skin, and schistosomiasis/rectum). The morphology of extracellular eosinophil sombrero vesicles was also compared with that of cytoplasmic eosinophil sombrero vesicles, isolated by subcellular fractionation from peripheral blood eosinophils. We demonstrated that (i) eosinophil cytolysis, releasing intact sombrero vesicles and membrane-bound granules, is a consistent event in all eosinophil-associated diseases; (ii) eosinophil sombrero vesicles persist intact even after complete disintegration of all cell organelles, except granules (late cytolysis); (iii) the eosinophil sombrero vesicle population, composed of elongated, curved, and typical sombreros, and the eosinophil sombrero vesicle 3-dimensional architecture, diameter, and density remain unchanged in the extracellular matrix; (iv) free eosinophil sombrero vesicles closely associate with extracellular granules; and (v) free eosinophil sombrero vesicles also associate with externalized chromatin during eosinophil ETosis. Remarkably, eosinophil sombrero vesicles appeared on the surface of other cells, such as plasma cells. Thus, eosinophil cytolysis/ETosis can secrete intact sombrero vesicles, alongside granules, in inflamed tissues of eosinophil-associated diseases, potentially serving as propagators of eosinophil immune responses after cell death.

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This work assessed the impact of laser wavelength and sample conditioning on offline monitoring (viable cell density, cell viability, virus titer, glucose, lactate, glutamine, glutamate, and ammonium) of SARS-CoV-2 viruslike particles production upstream stage by Raman spectroscopy. The evaluated chemometrics techniques were Partial Least Squares (PLS) and Artificial Neural Networks (ANN), and different spectral filtering approaches were also considered. ANN showed better prediction capacity for most of the parameters, but ammonium and lactate, better predicted by PLS, and glutamine, no difference between modeling techniques was detected. For cell growth parameters and virus titer, samples without cells measured at 785 nm Raman laser wavelength originated better-adjusted models. This laser wavelength was also more appropriate for the remaining monitored experimental parameters except for glucose, in which the best model came from the spectral database acquired at 1064 nm wavelength. Cell remotion significantly increased the accuracy of viable cell density, cell viability, glutamate, and virus titer models. However, glucose, lactate, and ammonium models showed better prediction capacity for samples containing cells. Thus, it was demonstrated that laser wavelength, sample conditioning, spectral preprocessing, and chemometric modeling techniques need to be tailored for each experimental parameter to improve accuracy.

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Tomato plants are sensitive to drought stress throughout their growth cycle. To be considered drought-tolerant, a cultivar should display tolerance at all developmental stages. This study aimed to evaluate whether Solanum pennellii introgression lines (ILs) previously selected as drought-tolerant during germination/seedling growth maintained this tolerance in the vegetative/reproductive stage. We then investigated these ILs to uncover candidate genes. The plants were subjected to two different environmental conditions: well-watered and drought-stressed (water withheld for ≤ 20 d after flowering). Phenotyping for morphological, physiological, fruit quality, and yield-related traits was performed, and the data was analyzed using a mixed-model approach. Using a multi-trait index that relies on factor analysis and genotype-ideotype distance (FAI-BLUP index), the genotypes were ordered based on how far they were from the drought-tolerant ideotype. Afterward, the tomato IL population map furnished by the SOL Genomics Network was utilized to identify introgressed segments of significance for the identification of candidate genes. Significant genotypic differences were found in the yield, water content, mean weight, length, and width of the fruit, the percentage of fruits displaying blossom-end rot, and titratable acidity. The drought-tolerance ideotype was built considering the maximum values for the fruit water content, number of fruits, mean fruit weight, and yield, minimum values for blossom-end rot, and mean values for titratable acidity. IL 1-4-18, IL 7-4-1, IL 7-1, IL 7-5-5, and IL 1-2 were ranked above M-82 and therefore considered drought-tolerant during the vegetative/reproductive stage. IL 1-4-18 and IL1-2 sustained drought tolerance displayed during germination/seedling growth into the vegetative/reproductive stage. The following candidate genes associated with drought tolerance were identified: AHG2, At1g55840, PRXIIF, SAP5, REF4-RELATED 1, PRXQ, CFS1, LCD, CCD1, and SCS. Because they are already associated with genetic markers, they can be transferred to elite tomato cultivars through marker-assisted technology after validation.

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BACKGROUND: Fibroblast-like synoviocytes (FLS) play a prominent role in rheumatoid synovitis and degradation of the extracellular matrix through the production of inflammatory cytokines and metalloproteinases (MMPs). Since animal models are frequently used for elucidating the disease mechanism and therapeutic development, it is relevant to study the ultrastructural characteristics and functional responses in human and mouse FLS. The objective of the study was to analyze ultrastructural characteristics, Interleukin-6 (IL-6) and Metalloproteinase-3 (MMP-3) production and the activation of intracellular pathways in Fibroblast like synoviocytes (FLS) cultures obtained from patients with rheumatoid arthritis (RA) and from mice with collagen-induced arthritis (CIA). METHODS: FLSs were obtained from RA patients (RA-FLSs) (n = 8) and mice with CIA (CIA-FLSs) (n = 4). Morphology was assessed by transmission and scanning electron microscopy. IL-6 and MMP-3 production was measured by ELISA, and activation of intracellular signaling pathways (NF-κB and MAPK: p-ERK1/2, p-P38 and p-JNK) was measured by Western blotting in cultures of RA-FLSs and CIA-FLSs stimulated with tumor necrosis factor-alpha (TNF-α) and IL-1ß. RESULTS: RA-FLS and CIA-FLS cultures exhibited rich cytoplasm, rough endoplasmic reticula and prominent and well-developed Golgi complexes. Transmission electron microscopy demonstrated the presence of lamellar bodies, which are cytoplasmic structures related to surfactant production, in FLSs from both sources. Increased levels of pinocytosis and numbers of pinocytotic vesicles were observed in RA-FLSs (p < 0.05). Basal production of MMP-3 and IL-6 was present in RA-FLSs and CIA-FLSs. Regarding the production of MMP-3 and IL-6 and the activation of signaling pathways, the present study demonstrated a lower response to IL-1ß by CIA-FLSs than by RA-FLSs. CONCLUSION: This study provides a comprehensive understanding of the biology of RA-FLS and CIA-FLS. The differences and similarities in ultrastructural morphology and important inflammatory cytokines shown, contribute to future in vitro studies using RA-FLS and CIA-FLS, in addition, they indicate that the adoption of CIA-FLS for studies should take careful and be well designed, since they do not completely resemble human diseases.

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Gallic acid is a powerful antioxidant with multiple therapeutic applications, usually obtained from the acidic hydrolysis of tannins produced by many plants. As this process generates a considerable amount of toxic waste, the use of tannases or tannase-producing microorganisms has become a greener alternative over the last years. However, their high costs still impose some barriers for industrial scalability, requiring solutions that could be both greener and cost-effective. Since Pseudomonas putida KT2440 is a powerful degrader of gallic acid, its metabolism offers pathways that can be engineered to produce it from cheap and renewable carbon sources, such as the crude glycerol generated in biodiesel units. In this study, a synthetic operon with the heterologous genes aroG4, quiC and pobA* was developed and expressed in P. putida, based on an in silico analysis of possible metabolic routes, resulting in no production. Then, the sequences pcaHG and galTAPR were deleted from the genome of this strain to avoid the degradation of gallic acid and its main intermediate, the protocatechuic acid. This mutant was transformed with the vector containing the synthetic operon and was finally able to convert glycerol into gallic acid. Production assays in shaker showed a final concentration of 346.7 ± 0.004 mg L-1 gallic acid after 72 h.

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Abstract Background Fibroblast-like synoviocytes (FLS) play a prominent role in rheumatoid synovitis and degradation of the extracellular matrix through the production of inflammatory cytokines and metalloproteinases (MMPs). Since animal models are frequently used for elucidating the disease mechanism and therapeutic development, it is relevant to study the ultrastructural characteristics and functional responses in human and mouse FLS. The objective of the study was to analyze ultrastructural characteristics, Interleukin-6 (IL-6) and Metalloproteinase-3 (MMP-3) production and the activation of intracellular pathways in Fibroblast like synoviocytes (FLS) cultures obtained from patients with rheumatoid arthritis (RA) and from mice with collagen-induced arthritis (CIA). Methods FLSs were obtained from RA patients (RA-FLSs) (n = 8) and mice with CIA (CIA-FLSs) (n = 4). Morphology was assessed by transmission and scanning electron microscopy. IL-6 and MMP-3 production was measured by ELISA, and activation of intracellular signaling pathways (NF-κB and MAPK: p-ERK1/2, p-P38 and p-JNK) was measured by Western blotting in cultures of RA-FLSs and CIA-FLSs stimulated with tumor necrosis factor-alpha (TNF-α) and IL-1β. Results RA-FLS and CIA-FLS cultures exhibited rich cytoplasm, rough endoplasmic reticula and prominent and well- developed Golgi complexes. Transmission electron microscopy demonstrated the presence of lamellar bodies, which are cytoplasmic structures related to surfactant production, in FLSs from both sources. Increased levels of pinocytosis and numbers of pinocytotic vesicles were observed in RA-FLSs (p < 0.05). Basal production of MMP-3 and IL-6 was present in RA-FLSs and CIA-FLSs. Regarding the production of MMP-3 and IL-6 and the activation of signaling pathways, the present study demonstrated a lower response to IL-1β by CIA-FLSs than by RA-FLSs. Conclusion This study provides a comprehensive understanding of the biology of RA-FLS and CIA-FLS. The differences and similarities in ultrastructural morphology and important inflammatory cytokines shown, contribute to future in vitro studies using RA-FLS and CIA-FLS, in addition, they indicate that the adoption of CIA-FLS for studies should take careful and be well designed, since they do not completely resemble human diseases.

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Resumo Objetivou-se relatar a experiência no gerenciamento de pesquisa-ação sobre inquérito de hepatite C junto à comunidade carcerária no Triângulo Mineiro, Minas Gerais. A proposta foi desenvolvida entre março de 2019 e março de 2020, alcançando 240 pessoas, com o intuito de conter a disseminação do agravo por meio de inquérito, testagem e acompanhamento dos casos positivos. Adotou-se ação intersetorial, com articulação entre universidades, sociedade médica, hospital de ensino e Secretaria de Estado de Justiça e Segurança Pública. As estratégias para o gerenciamento da pesquisa-ação foram: cenários e atores do estudo, registro e formalização da atividade, aplicação dos testes e manejo dos internos reagentes. Dificuldades foram identificadas quanto à acomodação de rotinas entre equipe de pesquisadores e funcionamento próprio da penitenciária, o que exigiu treinamento ostensivo entre as partes e articulações gerenciais. Considera-se que o relato, quando destaca as estratégias adotadas para a condução da pesquisa, colabora para a organização de investigações futuras que visem acessar essa população ainda invisibilizada.

Abstract We aimed to report the experience in managing action research on hepatitis C investigation in the prison community in the Triângulo Mineiro region, Minas Gerais, Brazil. The proposal was developed from March 2019 to March 2020, reaching 240 people to contain the spread of the disease through a survey, testing, and monitoring of positive cases. We adopted intersectoral action with articulation between Universities, Medical Society, Teaching Hospital, and State Secretariat for Justice and Public Security. Strategies for the management of action research are described: study settings and stakeholders, registration and formalization of the activity, application of tests, and management of reagent inmates. We identified difficulties regarding the accommodation of routines among the research team and the proper functioning of the penitentiary, which required extensive training between the parties and managerial articulations. We consider that the report collaborates with the organization of future research aimed at accessing this still invisible population, the prison community when it highlights the strategies adopted to conduct the research.

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We aimed to report the experience in managing action research on hepatitis C investigation in the prison community in the Triângulo Mineiro region, Minas Gerais, Brazil. The proposal was developed from March 2019 to March 2020, reaching 240 people to contain the spread of the disease through a survey, testing, and monitoring of positive cases. We adopted intersectoral action with articulation between Universities, Medical Society, Teaching Hospital, and State Secretariat for Justice and Public Security. Strategies for the management of action research are described: study settings and stakeholders, registration and formalization of the activity, application of tests, and management of reagent inmates. We identified difficulties regarding the accommodation of routines among the research team and the proper functioning of the penitentiary, which required extensive training between the parties and managerial articulations. We consider that the report collaborates with the organization of future research aimed at accessing this still invisible population, the prison community when it highlights the strategies adopted to conduct the research.

Objetivou-se relatar a experiência no gerenciamento de pesquisa-ação sobre inquérito de hepatite C junto à comunidade carcerária no Triângulo Mineiro, Minas Gerais. A proposta foi desenvolvida entre março de 2019 e março de 2020, alcançando 240 pessoas, com o intuito de conter a disseminação do agravo por meio de inquérito, testagem e acompanhamento dos casos positivos. Adotou-se ação intersetorial, com articulação entre universidades, sociedade médica, hospital de ensino e Secretaria de Estado de Justiça e Segurança Pública. As estratégias para o gerenciamento da pesquisa-ação foram: cenários e atores do estudo, registro e formalização da atividade, aplicação dos testes e manejo dos internos reagentes. Dificuldades foram identificadas quanto à acomodação de rotinas entre equipe de pesquisadores e funcionamento próprio da penitenciária, o que exigiu treinamento ostensivo entre as partes e articulações gerenciais. Considera-se que o relato, quando destaca as estratégias adotadas para a condução da pesquisa, colabora para a organização de investigações futuras que visem acessar essa população ainda invisibilizada.

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A meningite bacteriana é uma inflamação das leptomeninges que envolvem o Sistema Nervoso Central. Essa patologia, que possui diversos agentes etiológicos, apresenta-se na forma de síndrome, com quadro clínico grave. Entre as principais bactérias que causam a meningite, estão a Neisseria meningitis e Streptococcus pneumoniae. A transmissão ocorre através das vias aéreas por meio de gotículas, sendo a corrente sanguínea a principal rota para as bactérias chegarem à barreira hematoencefálica e, a partir dessa, até as meninges. Atualmente existem vários métodos de diagnóstico precisos, onde a cultura de líquido cefalorraquidiano (LCR) é o método padrão ouro. Ademais, a melhora na qualidade do tratamento com beta-lactâmicos e a maior possibilidade de prevenção, devido à elevação do número e da eficácia de vacinas, vem contribuindo para redução dos casos da doença e de sua gravidade. Porém, apesar desses avanços, ainda há um elevado número de mortalidades e sequelas causadas por essa síndrome.

Bacterial meningitis is an inflammation of the leptomeninges that surround the Central Nervous System. This pathology, which has several etiological agents, is presented as a syndrome with a severe clinical scenario. The main bacteria causing meningitis include Neisseria meningitis and Streptococcus pneumoniae. It can be transmitted by droplets through the airways, with the bacteria using the bloodstream as the main route to reach the blood-brain barrier, and from there to the meninges. There are currently several accurate diagnostic methods, with CSF culture being the gold standard. In addition, the improvement in the quality of beta-lactam treatment and the greater possibility of prevention due to the increased number and effectiveness of vaccines have contributed to reducing the number of cases and severity of the disease. Nevertheless, despite these advances, this syndrome still presents a high number of mortalities and sequelae.

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Lycosa is one of the most speciose genera in Lycosidae, including species with different sexual chromosome systems (SCS). We carried out cytogenetic analyses in three species of Lycosa, revealing that L. erythrognatha and L. sericovittata share 2n ♂ = 22 and SCS X1X20 while L. gr. nordenskjoldi presents 2n ♂ = 19 and SCS XO, composed only of acrocentric chromosomes. All species shared pericentromeric heterochromatin. Nonetheless, one specimen of L. sericovittata carried two chromosomes with terminal heterochromatin and L. gr. nordenskjoldi showed four chromosomes with interstitial heterochromatin plus another chromosome with terminal C-bands. The pericentromeric heterochromatin of all species as well as the terminal heterochromatic blocks in L. sericovittata were CMA3+. The 18S rDNA sites varied in number and type of bearing chromosomes both at inter and intrapopulational levels, with the highest variation in L. gr. nordenskjoldi. These differences may be related to gene dispersal due to the influence of transposition elements and translocation events. Despite these variations, all species shared ribosomal sites in pair 5. This study demonstrated intra and interspecific chromosomal variability of Lycosa, suggesting that chromosomal rearrangements are related to the diversification of diploid number and SCS in this group of spiders.

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Brazil is the largest producer of soybeans in the world. The vast extent of soybean plantations across the Brazilian territory exposes this crop to attack by several insects, including the velvetbean caterpillar, Anticarsia gemmatalis. One of the alternatives used to control this insect are the toxins produced by Bacillus thuringiensis (Bt). However, in some cases, resistance to these toxins has been reported in the laboratory. Despite the ecological and economic impact of the velvetbean caterpillar, there are few studies on the genetic structure of this species, especially with regard to microsatellites. In this paper, we carried out a comparative transcriptional analysis of microsatellites in resistant (RES) and susceptible (SUS) strains of A. gemmatalis challenged and not challenged with Bt toxins. According to the number of sequences analyzed in each group, a 7.9% simple sequence repeat (SSR) rate was identified for the SUS library, and 7.4% for SUSBt. For the RES group, this value was 8.5% and for the RESBt 7.7%. Most of the fragments found showed a shorter repeat pattern, located in mono- and trinucleotide motifs. Among the 128 types of SSR motifs, it was possible to notice a large amount of adenine and thymine in relation to guanine and cytosine, which was also seen in chromosomes after staining with base-specific fluorochromes DAPI/CMA3, highlighting DAPI-positive regions. Although the participation of microsatellites in the resistance mechanism of A. gemmatalis to Bt is not clear, the results obtained in this work contribute to a better understanding of the repetitive DNA found in transcribed regions of a non-model organism.

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Lycosa is one of the most speciose genera in Lycosidae, including species with different sexual chromosome systems (SCS). We carried out cytogenetic analyses in three species of Lycosa, revealing that L. erythrognatha and L. sericovittata share 2n ♂ = 22 and SCS X1X20 while L. gr. nordenskjoldi presents 2n ♂ = 19 and SCS XO, composed only of acrocentric chromosomes. All species shared pericentromeric heterochromatin. Nonetheless, one specimen of L. sericovittata carried two chromosomes with terminal heterochromatin and L. gr. nordenskjoldi showed four chromosomes with interstitial heterochromatin plus another chromosome with terminal C-bands. The pericentromeric heterochromatin of all species as well as the terminal heterochromatic blocks in L. sericovittata were CMA3+. The 18S rDNA sites varied in number and type of bearing chromosomes both at inter and intrapopulational levels, with the highest variation in L. gr. nordenskjoldi. These differences may be related to gene dispersal due to the influence of transposition elements and translocation events. Despite these variations, all species shared ribosomal sites in pair 5. This study demonstrated intra and interspecific chromosomal variability of Lycosa, suggesting that chromosomal rearrangements are related to the diversification of diploid number and SCS in this group of spiders.

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The pathogenic protist Trypanosoma cruzi uses kissing bugs as invertebrate hosts that vectorize the infection among mammals. This parasite oxidizes proline to glutamate through two enzymatic steps and one nonenzymatic step. In insect vectors, T. cruzi differentiates from a noninfective replicating form to nonproliferative infective forms. Proline sustains this differentiation, but to date, a link between proline metabolism and differentiation has not been established. In T. cruzi, the enzymatic steps of the proline-glutamate oxidation pathway are catalyzed exclusively by the mitochondrial enzymes proline dehydrogenase [TcPRODH, EC: 1.5.5.2] and Δ1-pyrroline-5-carboxylate dehydrogenase [TcP5CDH, EC: 1.2.1.88]. Both enzymatic steps produce reducing equivalents that are able to directly feed the mitochondrial electron transport chain (ETC) and thus produce ATP. In this study, we demonstrate the contribution of each enzyme of the proline-glutamate pathway to ATP production. In addition, we show that parasites overexpressing these enzymes produce increased levels of H2O2, but only those overexpressing TcP5CDH produce increased levels of superoxide anion. We show that parasites overexpressing TcPRODH, but not parasites overexpressing TcP5CDH, exhibit a higher rate of differentiation into metacyclic trypomastigotes in vitro. Finally, insect hosts infected with parasites overexpressing TcPRODH showed a diminished parasitic load but a higher percent of metacyclic trypomastigotes, when compared with controls. Our data show that parasites overexpressing both, PRODH and P5CDH had increased mitochondrial functions that orchestrated different oxygen signaling, resulting in different outcomes in relation to the efficiency of parasitic differentiation in the invertebrate host.

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Aedes aegypti mosquitoes transmit arboviruses of important global health impact, and their intestinal microbiota can influence vector competence by stimulating the innate immune system. Midgut epithelial cells also produce toxic reactive oxygen species (ROS) by dual oxidases (DUOXs) that are essential players in insect immunity. Strigomonas culicis is a monoxenous trypanosomatid that naturally inhabits mosquitoes; it hosts an endosymbiotic bacterium that completes essential biosynthetic pathways of the parasite and influences its oxidative metabolism. Our group previously showed that S. culicis hydrogen peroxide (H2O2)-resistant (WTR) strain is more infectious to A. aegypti mosquitoes than the wild-type (WT) strain. Here, we investigated the influence of both strains on the midgut oxidative environment and the effect of infection on mosquito fitness and immunity. WT stimulated the production of superoxide by mitochondrial metabolism of midgut epithelial cells after 4 days post-infection, while WTR exacerbated H2O2 production mediated by increased DUOX activity and impairment of antioxidant system. The infection with both strains also disrupted the fecundity and fertility of the females, with a greater impact on reproductive fitness of WTR-infected mosquitoes. The presence of these parasites induced specific transcriptional modulation of immune-related genes, such as attacin and defensin A during WTR infection (11.8- and 6.4-fold, respectively) and defensin C in WT infection (7.1-fold). Thus, we propose that A. aegypti oxidative response starts in early infection time and does not affect the survival of the H2O2-resistant strain, which has a more efficient antioxidant system. Our data provide new biological aspects of A. aegypti-S. culicis relationship that can be used later in alternative vector control strategies.

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