Expanding geographic distribution knowledge of Galerinamarginata (Batsch) Kühner (Agaricales, Hymenogastraceae) with a novel Antarctic record.

Background: The investigation of Agaricales diversity in the Antarctica is limited, with only seven genera reported for the region. Galerina stands out as the genus with the highest species diversity, including 12 species in Antarctica. This research reports the presence of G.marginata in the region, providing the first complete morphological description for the specimen developing in Antarctica. Sampling was conducted during the Austral summer of 2022/2023 as part of the XLI Brazilian Antarctic Operation in Point Smellie, Byers Peninsula, Livingston Island, South Shetland Archipelago, Antarctica. Phylogenetic relationships reconstructed by Maximum Likelihood demonstrate that G.marginata forms a monophyletic clade with over 60% bootstrap support in most branches. The isolate in this study was found to be internal to the main cluster. Evolutionary reconstructions using the Maximum Likelihood method indicate that the branches correspond to the Antarctic isolate being an internal clade within the marginata group. Recording fungal populations in polar regions offers information about their adaptation and survival in inhospitable environments. Understanding the species' distribution in Antarctica encourages future investigations into its ecology and interactions with other organisms. Here, data are presented to establish an initial foundation for monitoring the G.marginata population in Antarctica and assessing the potential impacts of climate change on its development and survival in the forthcoming years. New information: We report the third occurrence of Galerinamarginata (Batsch) Kühner in Antarctica and provide, for the first time, a comprehensive morphological description of an individual of the species for the Antarctic continent, accompanied by phylogenetic analyses and comprehensive discussions regarding its diversity and global distribution.

Genomic Landscape Comparison of Cardiac versus Extra-Cardiac Angiosarcomas.

Angiosarcomas (ASs) are rare malignant vascular entities that can affect several regions in our body, including the heart. Cardiac ASs comprise 25-40% of cardiac sarcomas and can cause death within months of diagnosis. Thus, our aim was to identify potential differences and/or similarities between cardiac and extra-cardiac ASs to enhance targeted therapies and, consequently, patients' prognosis. Whole-transcriptome analysis of three cardiac and eleven extra-cardiac non-cutaneous samples was performed to investigate differential gene expression and mutational events between the two groups. The gene signature of cardiac and extra-cardiac non-cutaneous ASs was also compared to that of cutaneous angiosarcomas (n = 9). H/N/K-RAS and TP53 alterations were more recurrent in extra-cardiac ASs, while POTE-gene family overexpression was peculiar to cardiac ASs. Additionally, in vitro functional analyses showed that POTEH upregulation conferred a growth advantage to recipient cells, partly supporting the cardiac AS aggressive phenotype and patients' scarce survival rate. These features should be considered when investigating alternative treatments.

Preclinical Models of Visceral Sarcomas.

Visceral sarcomas are a rare malignant subgroup of soft tissue sarcomas (STSs). STSs, accounting for 1% of all adult tumors, are derived from mesenchymal tissues and exhibit a wide heterogeneity. Their rarity and the high number of histotypes hinder the understanding of tumor development mechanisms and negatively influence clinical outcomes and treatment approaches. Although some STSs (~20%) have identifiable genetic markers, as specific mutations or translocations, most are characterized by complex genomic profiles. Thus, identification of new therapeutic targets and development of personalized therapies are urgent clinical needs. Although cell lines are useful for preclinical investigations, more reliable preclinical models are required to develop and test new potential therapies. Here, we provide an overview of the available in vitro and in vivo models of visceral sarcomas, whose gene signatures are still not well characterized, to highlight current challenges and provide insights for future studies.

The PPAR-γ Agonist Pioglitazone Modulates Proliferation and Migration in HUVEC, HAOSMC and Human Arteriovenous Fistula-Derived Cells.

The failure of arteriovenous fistulas (AVFs) following intimal hyperplasia (IH) increases morbidity and mortality rates in patients undergoing hemodialysis for chronic kidney disease. The peroxisome-proliferator associated receptor (PPAR-γ) may be a therapeutic target in IH regulation. In the present study, we investigated PPAR-γ expression and tested the effect of pioglitazone, a PPAR-γ agonist, in different cell types involved in IH. As cell models, we used Human Endothelial Umbilical Vein Cells (HUVEC), Human Aortic Smooth Muscle Cells (HAOSMC), and AVF cells (AVFCs) isolated from (i) normal veins collected at the first AVF establishment (T0), and (ii) failed AVF with IH (T1). PPAR-γ was downregulated in AVF T1 tissues and cells, in comparison to T0 group. HUVEC, HAOSMC, and AVFC (T0 and T1) proliferation and migration were analyzed after pioglitazone administration, alone or in combination with the PPAR-γ inhibitor, GW9662. Pioglitazone negatively regulated HUVEC and HAOSMC proliferation and migration. The effect was antagonized by GW9662. These data were confirmed in AVFCs T1, where pioglitazone induced PPAR-γ expression and downregulated the invasive genes SLUG, MMP-9, and VIMENTIN. In summary, PPAR-γ modulation may represent a promising strategy to reduce the AVF failure risk by modulating cell proliferation and migration.

Genomic Characterization of Rare Primary Cardiac Sarcoma Entities.

Primary cardiac sarcomas are considered rare malignant entities associated with poor prognosis. In fact, knowledge regarding their gene signature and possible treatments is still limited. In our study, whole-transcriptome sequencing on formalin-fixed paraffin-embedded (FFPE) samples from one cardiac osteosarcoma and one cardiac leiomyosarcoma was performed, to investigate their mutational profiles and to highlight differences and/or similarities to other cardiac histotypes. Both cases have been deeply detailed from a pathological point of view. The osteosarcoma sample presented mutations involving ATRX, ERCC5, and COL1A1, while the leiomyosarcoma case showed EXT2, DNM2, and PSIP1 alterations. Altered genes, along with the most differentially expressed genes in the leiomyosarcoma or osteosarcoma sample versus the cardiac angiosarcomas and intimal sarcomas (e.g., YAF2, PAK5, and CRABP1), appeared to be associated with cell growth, proliferation, apoptosis, and the repair of DNA damage, which are key mechanisms involved in tumorigenesis. Moreover, a distinct gene expression profile was detected in the osteosarcoma sample when compared to other cardiac sarcomas. For instance, WIF1, a marker of osteoblastic differentiation, was upregulated in our bone tumor. These findings pave the way for further studies on these entities, in order to identify targeted therapies and, therefore, improve patients' prognoses.

Percepção do pré-natal odontológico pelas gestantes e puérperas atendidas em um hospital maternidade / Perception of dental prenatal care by pregnant and postpartum women assisted in a maternity hospital / Percepción de la atención prenatal dental por parte de las mujeres embarazadas y puérperas atendidas en una maternidad

Objetivo: compreender a percepção de gestantes e puérperas a respeito do pré-natal odontológico. Método: estudo descritivo, exploratório com abordagem qualitativa, realizado em um Hospital Maternidade de um município do interior cearense, mediante entrevistas junto as gestantes, a partir do terceiro trimestre, e puérperas. A coleta de dados ocorreu em 2020. Em seguida, o conteúdo empírico foi analisado e categorizado em seguindo os pressupostos da análise temática. Resultados: participaram da pesquisa, 20 mulheres entre gestantes e puérperas. A partir da percepção das participantes, foram elaboradas três categorias, a saber: a percepção do pré-natal odontológico, segundo a ótica das gestantes e puérperas; relações dialógicas entre gestantes e profissionais de saúde; e implicações da falta de informação sobre a assistência odontológica na gestação. Conclusão: as gestantes reconhecem que o acompanhamento odontológico no período da gravidez é importante, mas demonstraram não entender quais as consequências positivas da assistência

Objective: to understand the perception of pregnant and postpartum women about dental prenatal care. Methods: descriptive, exploratory study with qualitative approach, conducted in a maternity hospital of a city in the interior of ceará, through interviews with pregnant women, from the third trimester, and postpartum women. Data collection occurred in 2020. Then, the empirical content was analyzed and categorized following the assumptions of thematic analysis. Results: twenty women among pregnant and postpartum women participated in the research. From the perception of the participants, three categories were elaborated, namely: the perception of dental prenatal care, according to the pregnant and postpartum women's point of view; dialogical relations between pregnant women and health professionals; and implications of the lack of information on dental care during pregnancy. Conclusion: pregnant women recognize that dental care during pregnancy is important, but they do not understand the positive consequences or the meaning of this assistance

Objetivo: conocer la percepción de las mujeres embarazadas y puérperas sobre el cuidado prenatal dental. Métodos: estudio descriptivo, exploratorio con abordaje cualitativo, realizado en un hospital materno de un municipio del interior cearense, mediante entrevistas junto a las gestantes, a partir del tercer trimestre, y puérperas. La recogida de datos se realizó en 2020. A continuación, el contenido empírico fue analizado y categorizado siguiendo los puntos de vista del análisis temático. Resultados: participaron en la investigación 20 mujeres entre gestantes y puérperas. A partir de la percepción de los participantes, se elaboraron tres categorías, a saber: la percepción del prenatal odontológico, según la óptica de las gestantes y puérperas; las relaciones dialógicas entre gestantes y profesionales de la salud; y las implicaciones de la falta de información sobre la asistencia odontológica en la gestación. Conclusión: las gestantes reconocen que el acompañamiento odontológico en el periodo de gestación es importante, pero demuestran no entender cuáles son las consecuencias positivas o el sentido de esta asistencia

Qualidade de vida e aspectos funcionais de pacientes pós-Covid-19 submetidos à reabilitação pulmonar / Quality of life and functional aspects of post-Covid-19 patients submitted to pulmonary rehabilitation

INTRODUÇÃO: pacientes que tiveram Covid-19, independente do espectro clínico da doença, podem apresentar sintomas persistentes após a alta hospitalar por até 14 meses. Estes pacientes apresentam comprometimentos funcionais e de qualidade de vida sendo, portanto, indicada a reabilitação pulmonar. Este estudo avaliou os aspectos funcionais e a qualidade de vida de pacientes pós-Covid-19 atendidos em um programa de reabilitação pulmonar. MÉTODOS: trata-se de um estudo prospectivo do tipo coorte clínica. Os pacientes pós-Covid-19 que integraram um programa de reabilitação pulmonar por seis semanas consecutivas foram avaliados em relação às variáveis funcionalidade pelo Índice de Barthel e pela escala PCFS, e a qualidade de vida pelo SF-36 na admissão (T0) e após seis semanas de reabilitação (T1). RESULTADOS: Onze pacientes que participaram do estudo apresentaram melhora da funcionalidade tanto pelo Índice de Barthel (p<0,01) como pela escala PCFS (p<0,01) e, também, melhora da qualidade de vida nos domínios capacidade funcional (p< 0,01), limitação por aspectos físicos (p<0,05) e aspectos sociais (p<0,01) no T1 em relação ao T0. CONCLUSÃO: pacientes pós-Covid-19 apresentaram melhora da funcionalidade e da qualidade de vida após um programa de reabilitação pulmonar (AU),

INTRODUCTION: patients who have Covid-19, regardless of the clinical spectrum of the disease, may present, after hospital discharge, persistent symptoms for up to 14 months. These patients have functional and quality of life impairments and, therefore, pulmonary rehabilitation for six consecutive weeks is indicated. This article evaluated the functional aspects and quality of life of post-Covid-19 patients treated in a pulmonary rehabilitation program. METHODS: this is a prospective clinical cohort study. Post-Covid-19 patients who joined a pulmonary rehabilitation program were evaluated concerning the variables functionality by the Barthel Index and the PCFS scale, and quality of life by the SF-36 at admission (T0) and after six weeks of rehabilitation treatment (T1). RESULTS: Eleven patients who participated in the study showed improved functionality both by the Barthel Index (p<0.01) and the PCFS scale (p<0.01) and also improved quality of life in the functional capacity domains (p < 0.01), limitation due to physical aspects (p<0.05) and social aspects (p<0.01) at T1 compared to T0. CONCLUSION: post-Covid-19 patients showed improved functionality and quality of life after a pulmonary rehabilitation program (AU).

Knowledge of Dentists about Hypomineralization Enamel Defects: A Cross-Sectional Study

ABSTRACT Objective: To evaluate a group of Brazilian dentists on their knowledge of Molar Incisor Hypomineralization (MIH) and Hypomineralized Second Primary Molars (HSPM) related to clinical aspects, consequences, and diagnostic criteria. Material and Methods: In this cross-sectional, the participants were invited by e-mail and Whatsapp® to answer a questionnaire about their knowledge of hypomineralization enamel defects (MIH/HSPM) on the Google Forms® platform. The questionnaire comprised eight questions about personal data and multiple-choice questions about their knowledge concerning clinical aspects, diagnostic criteria of MIH/HSPM and differential diagnosis through clinical images. Chi-square test was applied with the significance level set at 5%. Results: Most participants (n = 492; 91.1%) reported having knowledge about MIH/HSPM. The general dentists gave more incorrect answers (n = 40; 65.6 %;) about dental tissues affected by MIH/HSPM. Overall, 83.3% of the dentists gave the correct answer to which dentitions are associated with this condition. In addition, most dentists presented knowledge about the consequences related to possible fractures (n= 487; 90.2%) and about an increased risk of caries (n= 479; 88.9%) in the affected teeth. Regarding the differential diagnosis performed through clinical images, most participants gave incorrect answers (p≤0.001). Conclusion: The participants presented knowledge about the dentition associated with this condition and possible consequences related to the teeth affected by MIH/HSPM; however, they showed difficulties concerning clinical diagnostic criteria.

SRF Rearrangements in Soft Tissue Tumors with Muscle Differentiation.

The Serum Response Factor (SRF) is a transcription factor that regulates the expression of a wide set of genes involved in cell proliferation, migration, cytoskeletal organization and myogenesis. Accumulating evidence suggests that SRF may play a role in carcinogenesis and tumor progression in various neoplasms, where it is often involved in different fusion events. Here we investigated SRF rearrangements in soft tissue tumors, along with a gene expression profile analysis to gain insight into the oncogenic mechanism driven by SRF fusion. Whole transcriptome analysis of cell lines transiently overexpressing the SRF::E2F1 chimeric transcript uncovered the specific gene expression profile driven by the aberrant gene fusion, including overexpression of SRF-dependent target genes and of signatures related to myogenic commitment, inflammation and immune activation. This result was confirmed by the analysis of two cases of myoepitheliomas harboring SRF::E2F1 fusion with respect to EWSR1-fusion positive tumors. The recognition of the specific gene signature driven by SRF rearrangement in soft tissue tumors could aid the molecular classification of this rare tumor entity and support therapeutic decisions.

Air Pollution Exposure Induces Vascular Injury and Hampers Endothelial Repair by Altering Progenitor and Stem Cells Functionality.

Extensive evidence indicates an association of air pollution exposure with an increased risk of cardiovascular disease (CVD) development. Fine particulate matter (PM) represents one of the main components of urban pollution, but the mechanisms by which it exerts adverse effects on cardiovascular system remain partially unknown and under investigation. The alteration of endothelial functions and inflammation are among the earliest pathophysiological impacts of environmental exposure on the cardiovascular system and represent critical mediators of PM-induced injury. In this context, endothelial stem/progenitor cells (EPCs) play an important role in vascular homeostasis, endothelial reparative capacity, and vasomotor functionality modulation. Several studies indicate the impairment of EPCs' vascular reparative capacity due to PM exposure. Since a central source of EPCs is bone marrow (BM), their number and function could be related to the population and functional status of stem cells (SCs) of this district. In this review, we provide an overview of the potential mechanisms by which PM exposure hinders vascular repair by the alteration of progenitor and stem cells' functionality.

Chromosomal distribution of major rDNA and genome size variation in Belostoma angustum Lauck, B. nessimiani Ribeiro & Alecrim, and B. sanctulum Montandon (Insecta, Heteroptera, Belostomatidae).

Known as "electric-light bugs", belostomatids potentially act as agents of biological control. The Belostoma genus has holokinetic chromosomes, interspecific variation in diploid number, sex chromosome system and DNA content. Thus, the chromosomal complement, the accumulation of constitutive heterochromatin and the distribution of rDNA clusters by fluorescence in situ hybridization (FISH) in Belostoma angustum (BAN), Belostoma sanctulum (BSA), and Belostoma nessimiani (BNE) were evaluated. In addition, a comparative analysis of the DNA content of these species and B. estevezae (BES) was performed. BES has the highest Belostoma DNA content, while BSA has the lowest. BAN showed 2n = 29 + X1X2Y, while BSA and BNE had 2n = 14 + XY. BSA showed 18S rDNA markings on sex chromosomes, while BNE and BAN did on autosomes. The difference between BSA and BNE occurs because of the possible movement of the rDNA cluster in BNE. We suggest the occurrence of fusion in the autosomes of BSA and BNE, and fragmentation in the sex chromosomes in BAN. Also, the genome size of 1-2 pg represents a haploid DNA content of a common ancestor, from which the genomes of BES and BAN had evolved by gene duplication and heterochromatinization events.

Karyotype Evolution and Genomic Organization of Repetitive DNAs in the Saffron Finch, Sicalis flaveola (Passeriformes, Aves).

The Saffron finch (Sicalis flaveola), a semi-domestic species, is tolerant of human proximity and nesting in roof spaces. Considering the importance of cytogenomic approaches in revealing different aspects of genomic organization and evolution, we provide detailed cytogenetic data for S. flaveola, including the standard Giemsa karyotype, C- and G-banding, repetitive DNA mapping, and bacterial artificial chromosome (BAC) FISH. We also compared our results with the sister groups, Passeriformes and Psittaciformes, bringing new insights into the chromosome and genome evolution of birds. The results revealed contrasting rates of intrachromosomal changes, highlighting the role of SSR (simple short repetition probes) accumulation in the karyotype reorganization. The SSRs showed scattered hybridization, but brighter signals were observed in the microchromosomes and the short arms of Z chromosome in S. flaveola. BACs probes showed conservation of ancestral syntenies of macrochromosomes (except GGA1), as well as the tested microchromosomes. The comparison of our results with previous studies indicates that the great biological diversity observed in Passeriformes was not likely accompanied by interchromosomal changes. In addition, although repetitive sequences often act as hotspots of genome rearrangements, Passeriformes species showed a higher number of signals when compared with the sister group Psittaciformes, indicating that these sequences were not involved in the extensive karyotype reorganization seen in the latter.

HSP90 identified by a proteomic approach as druggable target to reverse platinum resistance in ovarian cancer.

Acquired resistance to platinum (Pt)-based therapies is an urgent unmet need in the management of epithelial ovarian cancer (EOC) patients. Here, we characterized by an unbiased proteomics method three isogenic EOC models of acquired Pt resistance (TOV-112D, OVSAHO, and MDAH-2774). Using this approach, we identified several differentially expressed proteins in Pt-resistant (Pt-res) compared to parental cells and the chaperone HSP90 as a central hub of these protein networks. Accordingly, up-regulation of HSP90 was observed in all Pt-res cells and heat-shock protein 90 alpha isoform knockout resensitizes Pt-res cells to cisplatin (CDDP) treatment. Moreover, pharmacological HSP90 inhibition using two different inhibitors [17-(allylamino)-17-demethoxygeldanamycin (17AAG) and ganetespib] synergizes with CDDP in killing Pt-res cells in all tested models. Mechanistically, genetic or pharmacological HSP90 inhibition plus CDDP -induced apoptosis and increased DNA damage, particularly in Pt-res cells. Importantly, the antitumor activities of HSP90 inhibitors (HSP90i) were confirmed both ex vivo in primary cultures derived from Pt-res EOC patients ascites and in vivo in a xenograft model. Collectively, our data suggest an innovative antitumor strategy, based on Pt compounds plus HSP90i, to rechallenge Pt-res EOC patients that might warrant further clinical evaluation.

Prática simulada no ensino sobre queimaduras para estudantes de enfermagem e medicina: Revisão integrativa / Simulated practice in teaching burns for nursing and medicine students: Integrative review

OBJETIVO: Analisar as evidências científicas sobre o uso da prática simulada como estratégia de ensino de estudantes de graduação em Enfermagem e Medicina sobre o tratamento de pessoas com lesões por queimaduras. MÉTODO: A busca foi realizada nas bases/bancos de dados eletrônicos PubMed, LILACS, Web of Science e Embase, sem determinação de limite temporal. Inicialmente, foram identificados 281 estudos potencialmente elegíveis, sendo 36 duplicados no gerenciador eletrônico de referências EndNote Web e, posteriormente, nove no software Rayyan QCR. RESULTADOS: Foram incluídos nessa revisão três artigos científicos. Em relação à força de evidência, foram encontrados níveis fraco e moderado de evidências. Os estudantes reportaram satisfação com as ferramentas utilizadas na simulação. O treino por simulação por meio de imagens de casos clínicos de queimados em cenário simulado possibilitou aos estudantes a identificação de temáticas como paciente-centrado, realismo e aprendizado. O uso de cenário baseado em simulação fornece um modelo estruturado e flexível na abordagem dos estudantes ao caso clínico de pessoa com lesões por queimaduras. CONCLUSÃO: Apesar da escassez dos estudos, a simulação aparenta ser (já que a força de evidência foi fraca e poucos estudos) valiosa ferramenta educativa, permitindo que os alunos ganhem experiência concreta que pode ser incorporada à prática da vida real e desenvolvam competências em ambientes educacionais mais seguros e controlados. Considera-se o treinamento por simulação um instrumento importante e eficaz para o ensino de cuidados de pessoas que sofreram queimaduras em todo o mundo.

OBJECTIVE: To analyze the evidence available in the literature on the use of simulation as a teaching method on burn treatment with nursing and medical students. METHODS: The search was performed in the electronic databases/databases PubMed, LILACS, Web of Science and Embase, without determining the time limit. Initially, 281 potentially eligible studies were identified, 36 of which were duplicated in the electronic reference manager EndNote Web and, later, nine in the Rayyan QCR software. RESULTS: Three scientific articles were included in this review. Students reported satisfaction with the tools used in the simulation; training by simulation through images of clinical burn cases in a simulated scenario allowed students to identify themes such as patient-centered, realism and learning. The use of scenario-based simulation provides a structured and flexible model in the students' approach to clinical case of a person with burn injuries. CONCLUSION: Despite the scarcity of studies, simulation appears to be (since the strength of evidence was weak and few studies) a valuable educational tool, allowing students to gain concrete experience that can be incorporated into real-life practice and to develop skills in more educational environments. safe and controlled. Simulation training is considered an important and effective tool for teaching care for people who have suffered burns around the world.

Introducing the Bird Chromosome Database: An Overview of Cytogenetic Studies in Birds.

Bird chromosomes, which have been investigated scientifically for more than a century, present a number of unique features. In general, bird karyotypes have a high diploid number (2n) of typically around 80 chromosomes that are divided into macro- and microchromosomes. In recent decades, FISH studies using whole chromosome painting probes have shown that the macrochromosomes evolved through both inter- and intrachromosomal rearrangements. However, chromosome painting data are available for only a few bird species, which hinders a more systematic approach to the understanding of the evolutionary history of the enigmatic bird karyotype. Thus, we decided to create an innovative database through compilation of the cytogenetic data available for birds, including chromosome numbers and the results of chromosome painting with chicken (Gallus gallus) probes. The data were obtained through an extensive literature review, which focused on cytogenetic studies published up to 2019. In the first version of the "Bird Chromosome Database (BCD)" (https://sites.unipampa.edu.br/birdchromosomedatabase) we have compiled data on the chromosome numbers of 1,067 bird species and chromosome painting data on 96 species. We found considerable variation in the diploid numbers, which ranged from 40 to 142, although most (around 50%) of the species studied up to now have between 78 and 82 chromosomes. Despite its importance for cytogenetic research, chromosome painting has been applied to less than 1% of all bird species. The BCD will enable researchers to identify the main knowledge gaps in bird cytogenetics, including the most under-sampled groups, and make inferences on chromosomal homologies in phylogenetic studies.

Comparative analyses of three swallow species (Aves, Passeriformes, Hirundinidae): Insights on karyotype evolution and genomic organization.

Despite the richness of species in the Hirudinidae family, little is known about the genome organization of swallows. The Progne tapera species presents genetic and morphological difference when compared to other members of the same genus. Hence, the aims of this study were to analyze the chromosomal evolution of three species Progne tapera, Progne chalybea and Pygochelidon cyanoleuca - by comparative chromosome painting using two sets of probes, Gallus gallus and Zenaida auriculata, in order to determine chromosome homologies and the relationship between these species. All karyotypes exhibited 76 chromosomes with similar morphology, except for the 5th, 6th and 7th chromosome pairs in P. cyanoleuca. Additionally, comparative chromosome painting demonstrated the same hybridization pattern in the two Progne, which was similar to the putative avian ancestral karyotype, except for the centric fission in the first pair, as found in other Passeriformes. Thus, these data display a close relationship between the Progne species. Although P. cyanoleuca demonstrated the same fission in the first pair of the ancestral syntenic (GGA1), it also showed an additional chromosomal rearrangement for this species, namely a fusion with a microchromosome in the seventh pair.

Comparative chromosome painting in hummingbirds (Trochilidae).

Hummingbirds (Trochilidae) are one of the most enigmatic avian groups, and also among the most diverse, with approximately 360 recognized species in 106 genera, of which 43 are monotypic. This fact has generated considerable interest in the evolutionary biology of the hummingbirds, which is reflected in a number of DNA-based studies. However, only a few of them explored chromosomal data. Given this, the present study provides an analysis of the karyotypes of three species of Neotropical hummingbirds, Anthracothorax nigricollis (ANI), Campylopterus largipennis (CLA), and Hylocharis chrysura (HCH), in order to analyze the chromosomal processes associated with the evolution of the Trochilidae. The diploid number of ANI is 2n=80 chromosomes, while CLA and HCH have identical karyotypes, with 2n=78. Chromosome painting with Gallus gallus probes (GGA1-12) shows that the hummingbirds have a karyotype close to the proposed ancestral bird karyotype. Despite this, an informative rearrangement was detected: an in-tandem fusion between GGA7 and GGA9 found in CLA and HCH, but absent in ANI. A comparative analysis with the tree of life of the hummingbirds indicated that this fusion must have arisen following the divergence of a number of hummingbird species.

Evolution of Bird Sex Chromosomes Narrated by Repetitive Sequences: Unusual W Chromosome Enlargement in Gallinula melanops (Aves: Gruiformes: Rallidae).

Among birds, species with the ZZ/ZW sex determination system generally show significant differences in morphology and size between the Z and W chromosomes (with the W usually being smaller than the Z). In the present study, we report for the first time the karyotype of the spot-flanked gallinule (Gallinula melanops) by means of classical and molecular cytogenetics. The spot-flanked gallinule has 2n = 80 (11 pairs of macrochromosomes and 29 pairs of microchromosomes) with an unusual W chromosome that is larger than the Z. Besides being totally heterochromatic, it has a secondary constriction in its long arm corresponding to the nucleolar organizer region, as confirmed by both silver staining and mapping of 18S rDNA probes. This is an unprecedented fact among birds. Additionally, 18S rDNA sites were also observed in 6 microchromosomes, while 5S rDNA was found in just 1 microchromosomal pair. Seven out of the 11 used microsatellite sequences were found to be accumulated in microchromosomes, and 6 microsatellite sequences were found in the W chromosome. In addition to the involvement of heterochromatin and repetitive DNAs in the differentiation of the large W chromosome, the results also show an alternative scenario that highlights the plasticity that shapes the evolutionary history of bird sex chromosomes.

Karyotype Evolution and Distinct Evolutionary History of the W Chromosomes in Swallows (Aves, Passeriformes).

As in many other bird groups, data on karyotype organization and distribution of repetitive sequences are also lacking in species belonging to the family Hirundinidae. Thus, in the present study, we analyzed the karyotypes of 3 swallow species (Progne tapera, Progne chalybea, and Pygochelidon cyanoleuca) by Giemsa and AgNOR staining, C-banding, and FISH with 11 microsatellite sequences. The diploid chromosome number was 2n = 76 in all 3 species, and NORs were observed in 2 chromosome pairs each. The microsatellite distribution pattern was similar in both Progne species, whereas P. cyanoleuca presented a distinct organization. These repetitive DNA sequences were found in the centromeric, pericentromeric, and telomeric regions of the macrochromosomes, as well as in 2 interstitial blocks in the W chromosome. Most microchromosomes had mainly telomeric signals. The Z chromosome displayed 1 hybridization signal in P. tapera but none in the other species. In contrast, the W chromosome showed an accumulation of different microsatellite sequences. The swallow W chromosome is larger than that of most Passeriformes. The observed enlargement in chromosome size might be explained by these high amounts of repetitive sequences. In sum, our data highlight the significant role that microsatellite sequences may play in sex chromosome differentiation.

USP1 links platinum resistance to cancer cell dissemination by regulating Snail stability.

Resistance to platinum-based chemotherapy is a common event in patients with cancer, generally associated with tumor dissemination and metastasis. Whether platinum treatment per se activates molecular pathways linked to tumor spreading is not known. Here, we report that the ubiquitin-specific protease 1 (USP1) mediates ovarian cancer cell resistance to platinum, by regulating the stability of Snail, which, in turn, promotes tumor dissemination. At the molecular level, we observed that upon platinum treatment, USP1 is phosphorylated by ATM and ATR and binds to Snail. Then, USP1 de-ubiquitinates and stabilizes Snail expression, conferring resistance to platinum, increased stem cell-like features, and metastatic ability. Consistently, knockout or pharmacological inhibition of USP1 increased platinum sensitivity and decreased metastatic dissemination in a Snail-dependent manner. Our findings identify Snail as a USP1 target and open the way to a novel strategy to overcome platinum resistance and more successfully treat patients with ovarian cancer.