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OBJECTIVE: To explore the experiences of family physicians leading quality improvement (QI) efforts and to better understand facilitators and barriers related to advancing QI in family practice. DESIGN: Qualitative descriptive study. SETTING: The Department of Family and Community Medicine at the University of Toronto in Ontario. The department launched a quality and innovation program in 2011 with the dual goals of teaching QI skills to learners and supporting faculty in leading QI efforts in practice. PARTICIPANTS: Family physician faculty who held QI leadership roles at any of the department's 14 teaching units between 2011 and 2018. METHODS: Fifteen semistructured telephone interviews were conducted over 3 months in 2018. Analysis was informed by a qualitative descriptive approach. Consistency of responses across the interviews was suggestive of thematic saturation. MAIN FINDINGS: Substantial variation was found in the level of engagement with QI in practice settings despite the common training, forms of support, and curriculum the department provided. Four factors influenced the uptake of QI. First, committed leadership across the organization was fundamental to developing an effective QI culture. Second, external drivers such as mandatory QI plans sometimes motivated engagement in QI but sometimes were barriers, particularly when internal priorities conflicted with external demands. Third, at many practices, QI was widely perceived as extra work rather than as a way to enable better patient care. Finally, physicians described lack of time and resources as a challenge, particularly in community practices, and advocated for practice facilitation as a mechanism to support QI efforts. CONCLUSION: Advancing QI in primary care practice will require committed leaders, a clear understanding among physicians of the potential benefits of QI, alignment of external demands with internal drivers for improvement, and dedicated time for QI work along with support such as practice facilitation.
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Médicos de Familia , Mejoramiento de la Calidad , Humanos , Medicina Familiar y Comunitaria , Investigación Cualitativa , CurriculumRESUMEN
Context: More than 25% of Canadian seniors are prescribed 10+ different medications each year. There is a direct association between more medications and persistent high care needs/costs for seniors. Effective and appropriate deprescribing for seniors in primary care is needed. Objective: To present results of a feasibility study of the Structured Process Informed by Data, Evidence and Research (SPIDER) project aiming at improving safer deprescribing for complex older patients in community-based primary care. Study Design: Single-arm mixed methods study in Toronto, Ontario. Evaluation included participant interviews, focus groups, field notes and quantitative EMR data. Setting: Primary care practices affiliated with the University of Toronto Practice-Based Research Network (UTOPIAN). Population Studied: Patients aged 65+ years taking 10+ different medications. Intervention: 1) QI-focused Learning Collaboratives (LCs); 2) practice coaching; and 3) EMR data for audit & feedback. Outcome Measures: feasibility across eight dimensions: acceptability, demand, implementation, adaptation, integration, practicality, and efficacy. Results: Demand: 33 physicians and 24 allied health professionals from ten UTOPIAN practices and one community health centre participated in the Toronto LC. Implementation: the LC included a full day initial workshop, two short webinars, and a half-day summative congress over nine months. Practices had a monthly call with their QI coach and quarterly data reports. Adaptation, integration, practicality: teams developed various deprescribing tools and processes that were integratable to local context and existing practices. Acceptability: Teams perceived access to coaching as a valuable element of the approach. The initial review and validation of patients identified in the data reports were deemed time-consuming, particularly for under-resourced practices with a large cohort of target patient population. Access to pharmacist services and in-house QI and data support was considered two critical enablers to the sustainability of the approach. Efficacy: reductions in PIP prevalence and prevalence of patients with at least one PIP were 3.6% (p=.4) and 1.4% (p=.5), respectively. Conclusions: The SPIDER approach appears to be feasible. Access to coaching support and pharmacist services may enhance sustainability.
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Deprescripciones , Humanos , Anciano , Estudios de Factibilidad , Ontario , Farmacéuticos , Grupos FocalesRESUMEN
The veiled chameleon (Chamaeleo calyptratus) is a typical member of the family Chamaeleonidae and a promising object for comparative cytogenetics and genomics. The karyotype of C. calyptratus differs from the putative ancestral chameleon karyotype (2n = 36) due to a smaller chromosome number (2n = 24) resulting from multiple chromosome fusions. The homomorphic sex chromosomes of an XX/XY system were described recently using male-specific RADseq markers. However, the chromosomal pair carrying these markers was not identified. Here we obtained chromosome-specific DNA libraries of C. calyptratus by chromosome flow sorting that were assigned by FISH and sequenced. Sequence comparison with three squamate reptiles reference genomes revealed the ancestral syntenic regions in the C. calyptratus chromosomes. We demonstrated that reducing the chromosome number in the C. calyptratus karyotype occurred through two fusions between microchromosomes and four fusions between micro-and macrochromosomes. PCR-assisted mapping of a previously described Y-specific marker indicates that chromosome 5 may be the sex chromosome pair. One of the chromosome 5 conserved synteny blocks shares homology with the ancestral pleurodont X chromosome, assuming parallelism in the evolution of sex chromosomes from two basal Iguania clades (pleurodonts and acrodonts). The comparative chromosome map produced here can serve as the foundation for future genome assembly of chameleons and vertebrate-wide comparative genomic studies.
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Lagartos , Animales , Masculino , Sintenía/genética , Lagartos/genética , Cromosomas Sexuales/genética , Cromosomas , Genoma , Cariotipo , Evolución MolecularRESUMEN
Patients with high-grade serous ovarian cancer (HGSC) have experienced little improvement in overall survival, and standard treatment has not advanced beyond platinum-based combination chemotherapy, during the past 30 years. To understand the drivers of clinical phenotypes better, here we use whole-genome sequencing of tumour and germline DNA samples from 92 patients with primary refractory, resistant, sensitive and matched acquired resistant disease. We show that gene breakage commonly inactivates the tumour suppressors RB1, NF1, RAD51B and PTEN in HGSC, and contributes to acquired chemotherapy resistance. CCNE1 amplification was common in primary resistant and refractory disease. We observed several molecular events associated with acquired resistance, including multiple independent reversions of germline BRCA1 or BRCA2 mutations in individual patients, loss of BRCA1 promoter methylation, an alteration in molecular subtype, and recurrent promoter fusion associated with overexpression of the drug efflux pump MDR1.
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Resistencia a Antineoplásicos/efectos de los fármacos , Resistencia a Antineoplásicos/genética , Genoma Humano/genética , Neoplasias Ováricas/genética , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Estudios de Cohortes , Ciclina E/genética , Cistadenocarcinoma Seroso/tratamiento farmacológico , Cistadenocarcinoma Seroso/genética , Metilación de ADN , Análisis Mutacional de ADN , Proteínas de Unión al ADN/genética , Femenino , Genes BRCA1 , Genes BRCA2 , Genes de Neurofibromatosis 1 , Mutación de Línea Germinal/genética , Humanos , Mutagénesis/genética , Proteínas Oncogénicas/genética , Neoplasias Ováricas/tratamiento farmacológico , Fosfohidrolasa PTEN/genética , Regiones Promotoras Genéticas/genética , Proteína de Retinoblastoma/genéticaRESUMEN
Although Rallidae is the most diverse family within Gruiformes, there is little information concerning the karyotype of the species in this group. In fact, Gallinula melanops, a species of Rallidae found in Brazil, is among the few species studied cytogenetically, but only with conventional staining and repetitive DNA mapping, showing 2n=80. Thus, in order to understand the karyotypic evolution and phylogeny of this group, the present study aimed to analyze the karyotype of G. melanops by classical and molecular cytogenetics, comparing the results with other species of Gruiformes. The results show that G. melanops has the same chromosome rearrangements as described in Gallinula chloropus (Clade Fulica), including fission of ancestral chromosomes 4 and 5 of Gallus gallus (GGA), beyond the fusion between two of segments resultants of the GGA4/GGA5, also fusions between the chromosomes GGA6/GGA7. Thus, despite the fact that some authors have suggested the inclusion of G. melanops in genus Porphyriops, our molecular cytogenetic results confirm its place in the Gallinula genus.
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ISSUES ADDRESSED: Neurodivergent people have a strong history of raw creative expression in the arts, however they also have a history of being segregated from society. This segregation has obstructed pathways to building the connections that maintain both mental and physical health. This research sought to illuminate how group art-making impacts relationship formation with neurodivergent people in regional Australia. METHOD: The study included nine participants with intellectual disability and one with an acquired brain injury who regularly attend art-making workshops, along with eight of their chosen arts advocates. A single iterative case-study design was employed using participatory action research (PAR) methodology. Methods included: three participant think aloud (T/A) groups, nine researcher observations, and nine third-party interviews. The data were thematically analysed then triangulated using three different sources. RESULTS: Making art in a group can form enriched relationships with (a) the artwork; (b) the self; (c) others; and (d) community. Facilitation supported how these relationships formed. The relationships increased agency, belonging and wellbeing. CONCLUSION: These connections mitigate the numerous effects of marginalisation. Art-making has the capacity to enrich the health and wellbeing of neurodivergent populations. SO WHAT?: Art-making groups can provide a space that interrupts the isolation and social exclusion experienced by neurodivergent people. Art workshops offer both an emancipatory space to create where sense of self and relationships with others are enhanced, and an opportunity to reach beyond the studio to connect with communities. These rich connections contribute to better health outcomes for neurodivergent people, thus enhance the wellbeing of their communities.
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Arte , Discapacidad Intelectual , Australia , HumanosRESUMEN
Health equity allows people to reach their full health potential and receive high-quality care that is appropriate for them and their needs, no matter where they live, what they have, or who they are. It is a core element of quality in health care. Around the world, there are many efforts to improve equity through primary care. In order to advance these efforts, it is important to share successes and challenges. Building on our work with international stakeholders to identify key primary care research priorities, we organized the Toronto International Conference on Quality in Primary Care that was held on November 16, 2019. Participants from 8 countries took part. Key recommendations included the establishment of continuous relationships between providers and patients over time, relationships between providers in the health and social sectors, and resources supported proportionally to patient need. Solutions must be generated using team-based approaches that explicitly include people with who have experienced discrimination. Progress will require confronting structural determinants including racism, capitalism, and colonialism. Conference participants suggested practical solutions, such as developing a public transportation program for rural residents to improve community building and the ability to attend medical appointments, and identifying patients who have recently missed clinic visits that may benefit from additional care. These approaches will need to be evaluated through high-quality research and quality improvement, with a knowledge translation that facilitates sustainability and expansion across settings.
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Equidad en Salud , Atención Primaria de Salud , Mejoramiento de la Calidad/organización & administración , Determinantes Sociales de la Salud , Congresos como Asunto , Asignación de Recursos para la Atención de Salud , Recursos en Salud , Humanos , InternacionalidadRESUMEN
PURPOSE: Cancer therapy diminishes strength and physical function in cancer survivors. Whether oncology rehabilitation (OR) exercise training following therapy can correct these deficits, and whether its effectiveness differs by age, is not clear. We examine the utility of a clinically based, 12-week, combined aerobic and resistance training intervention on muscle strength and physical function in two age groups of cancer survivors. METHODS: Strength and physical function measures were assessed in middle-aged (45 to 64 years) and older (≥ 65 years) patients following treatment for stage 0-III cancer before and after the OR training program. RESULTS: Older patients had lower physical function compared to middle-aged patients across a range of subjective and objective measures at baseline, and exercise improved all indices of physical function and strength in both age groups. Compared to the middle-aged individuals, older participants tended to have less improvement leg strength and the 5 time sit to stand (5TSTS) test as a result of OR. In models predicting post-intervention measures, older age contributed to less improvement in walking distance and power as well as the 5TSTS test. CONCLUSION: Prior to beginning the OR exercise program, middle-aged patients had higher physical function compared to older patients. However, a 12-week aerobic and resistance training intervention improved physical function across both age groups, although older age did limit responsiveness in some physical function measures. The physical function and strength of middle-aged and older cancer survivors improve in response to an exercise-based OR program after cancer treatment.
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Supervivientes de Cáncer/psicología , Terapia por Ejercicio/métodos , Ejercicio Físico/fisiología , Fuerza Muscular/fisiología , Neoplasias/rehabilitación , Entrenamiento de Fuerza/métodos , Factores de Edad , Anciano , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Comparative chromosome-painting analysis among highly rearranged karyotypes of Sigmodontinae rodents (Rodentia, Cricetidae) detects conserved syntenic blocks, which are proposed as chromosomal signatures and can be used as phylogenetic markers. In the Akodontini tribe, the molecular topology (Cytb and/or IRBP) shows five low-supported clades (divisions: "Akodon", "Bibimys", "Blarinomys", "Oxymycterus", and "Scapteromys") within two high-supported major clades (clade A: "Akodon", "Bibimys", and "Oxymycterus"; clade B: "Blarinomys" and "Scapteromys"). Here, we examine the chromosomal signatures of the Akodontini tribe by using Hylaeamys megacephalus (HME) probes to study the karyotypes of Oxymycterus amazonicus (2n = 54, FN = 64) and Blarinomys breviceps (2n = 28, FN = 50), and compare these data with those from other taxa investigated using the same set of probes. We strategically employ the chromosomal signatures to elucidate phylogenetic relationships among the Akodontini. When we follow the evolution of chromosomal signature states, we find that the cytogenetic data corroborate the current molecular relationships in clade A nodes. We discuss the distinct events that caused karyotypic variability in the Oxymycterus and Blarinomys genera. In addition, we propose that Blarinomys may constitute a species complex, and that the taxonomy should be revised to better delimit the geographical boundaries and their taxonomic status.
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Cariotipo , Filogenia , Roedores/clasificación , Roedores/genética , Animales , Evolución Biológica , Brasil , Pintura Cromosómica , Citogenética/métodos , Geografía , Cariotipificación , Masculino , Sigmodontinae/clasificación , Sigmodontinae/genética , SinteníaRESUMEN
Cytogenetic analyses of the Suboscines species are still scarce, and so far, there is no karyotype description of any species belonging to the family Conopophagidae. Thus, the aim of this study is to describe and analyze the karyotype of Conopophaga lineata by chromosome painting using Gallus gallus (GGA) probes and to identify the location of the 18/28S rDNA cluster. Metaphases were obtained from fibroblast culture from two individuals of C. lineata. We observed a diploid number of 2n=78. GGA probes showed that most ancestral syntenies are conserved, except for the fission of GGA1 and GGA2, into two distinct pairs each. We identified the location of 18S rDNA genes in a pair of microchromosomes. The fission of the syntenic group corresponding to GGA2 was observed in other Furnariida, and hence may correspond to a chromosomal synapomorphy for the species of Parvorder Furnariida.
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The order Charadriiformes comprises three major clades: Lari and Scolopaci as sister group to Charadrii. Until now, only three Charadriiformes species have been studied by chromosome painting: Larus argentatus (Lari), Burhinus oedicnemus and Vanellus chilensis (Charadrii). Hence, there is a lack of information concerning the third clade, Scolapaci. Based on this, and to gain a better understanding of karyotype evolution in the order Charadriiformes, we applied conventional and molecular cytogenetic approaches in a species belonging to clade Scolopaci - the wattled jacana (Jacana jacana) - using Gallus gallus and Zenaida auriculata chromosome-specific probes. Cross-species evaluation of J. jacana chromosomes shows extensive genomic reshuffling within macrochromosomes during evolution, with multiple fission and fusion events, although the diploid number remains at high level (2n=82). Interestingly, this species does not have the GGA7-8 fusion, which was found in two representatives of Charadrii clade, reinforcing the idea that this fusion may be exclusive to the Charadrii clade. In addition, it is shown that the chromosome evolution in Charadriiformes is complex and resulted in species with typical and atypical karyotypes. The karyotypic features of Scolopaci are very different from those of Charadrii and Lari, indicating that after divergence, each suborder has undergone different chromosome rearrangements.
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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.
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BACKGROUND: The Neacomys genus is predominantly found in the Amazon region, and belongs to the most diverse tribe of the Sigmodontinae subfamily (Rodentia, Cricetidae, Oryzomyini). The systematics of this genus and questions about its diversity and range have been investigated by morphological, molecular (Cytb and COI sequences) and karyotype analysis (classic cytogenetics and chromosome painting), which have revealed candidate species and new distribution areas. Here we analyzed four species of Neacomys by chromosome painting with Hylaeamys megacephalus (HME) whole-chromosome probes, and compared the results with two previously studied Neacomys species and with other taxa from Oryzomyini and Akodontini tribes that have been hybridized with HME probes. Maximum Parsimony (MP) analyses were performed with the PAUP and T.N.T. software packages, using a non-additive (unordered) multi-state character matrix, based on chromosomal morphology, number and syntenic blocks. We also compared the chromosomal phylogeny obtained in this study with molecular topologies (Cytb and COI) that included eastern Amazonian species of Neacomys, to define the phylogenetic relationships of these taxa. RESULTS: The comparative chromosome painting analysis of the seven karyotypes of the six species of Neacomys shows that their diversity is due to 17 fusion/fission events and one translocation, pericentric inversions in four syntenic blocks, and constitutive heterochromatin (CH) amplification/deletion of six syntenic autosomal blocks plus the X chromosome. The chromosomal phylogeny is consistent with the molecular relationships of species of Neacomys. We describe new karyotypes and expand the distribution area for species from eastern Amazonia and detect complex rearrangements by chromosome painting among the karyotypes. CONCLUSIONS: Our phylogeny reflects the molecular relationships of the Akodontini and Oryzomyini taxa and supports the monophyly of Neacomys. This work presents new insights about the chromosomal evolution of this group, and we conclude that the karyotypic divergence is in accord with phylogenetic relationships.
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Pintura Cromosómica , Cromosomas de los Mamíferos/genética , Filogenia , Sigmodontinae/genética , Animales , Brasil , Sondas de ADN , Geografía , Cariotipo , SinteníaRESUMEN
The mammalian Y Chromosome sequence, critical for studying male fertility and dispersal, is enriched in repeats and palindromes, and thus, is the most difficult component of the genome to assemble. Previously, expensive and labor-intensive BAC-based techniques were used to sequence the Y for a handful of mammalian species. Here, we present a much faster and more affordable strategy for sequencing and assembling mammalian Y Chromosomes of sufficient quality for most comparative genomics analyses and for conservation genetics applications. The strategy combines flow sorting, short- and long-read genome and transcriptome sequencing, and droplet digital PCR with novel and existing computational methods. It can be used to reconstruct sex chromosomes in a heterogametic sex of any species. We applied our strategy to produce a draft of the gorilla Y sequence. The resulting assembly allowed us to refine gene content, evaluate copy number of ampliconic gene families, locate species-specific palindromes, examine the repetitive element content, and produce sequence alignments with human and chimpanzee Y Chromosomes. Our results inform the evolution of the hominine (human, chimpanzee, and gorilla) Y Chromosomes. Surprisingly, we found the gorilla Y Chromosome to be similar to the human Y Chromosome, but not to the chimpanzee Y Chromosome. Moreover, we have utilized the assembled gorilla Y Chromosome sequence to design genetic markers for studying the male-specific dispersal of this endangered species.
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Biología Computacional , Secuenciación de Nucleótidos de Alto Rendimiento , Mamíferos/genética , Cromosoma Y , Animales , Biología Computacional/métodos , Reordenamiento Génico , Genoma , Genómica , Gorilla gorilla/genética , Humanos , Secuencias Invertidas Repetidas , Masculino , Repeticiones de Microsatélite , Pan troglodytes/genética , Secuencias Repetitivas de Ácidos Nucleicos , Análisis de Secuencia de ADNRESUMEN
Supernumerary elements of the genome are often called B chromosomes. They usually consist of various autosomal sequences and, because of low selective pressure, are mostly pseudogenized and contain many repeats. There are numerous reports on B chromosomes in mammals, fish, invertebrates, plants, and fungi, but only a few of them have been studied using sequencing techniques. However, reptilian supernumerary chromosomes have been detected only cytogenetically and never sequenced or analyzed at the molecular level. One model squamate species with available genome sequence is Anolis carolinensis. The scope of the present article is to describe the genetic content of A. carolinensis supernumerary chromosomes. In this article, we confirm the presence of B chromosomes in this species by reverse painting and synaptonemal complex analysis. We applied low-pass high-throughput sequencing to analyze flow-sorted B chromosomes. Anole B chromosomes exhibit similar traits to other supernumerary chromosomes from different taxons: they contain two genes related to cell division control (INCENP and SPIRE2), are enriched in specific repeats, and show a high degree of pseudogenization. Therefore, the present study confirms that reptilian B chromosomes resemble supernumerary chromosomes of other taxons.
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Cromosomas/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Lagartos/genética , Análisis de Secuencia de ADN/métodos , Animales , División Celular , Proteínas Cromosómicas no Histona/genética , Mapeo Cromosómico , Pintura Cromosómica , Evolución Molecular , Proteínas de Microfilamentos/genética , FilogeniaRESUMEN
Chromosome homologies in reptiles have been investigated extensively by gene mapping and chromosome painting. Relative chromosome size can be estimated roughly from conventional karyotypes, but chromosome GC content cannot be evaluated by any of these approaches. However, GC content can be obtained by whole-genome sequencing, although complete data are available only for a limited number of reptilian species. Chromosomes can be characterized by size and GC content in bivariate flow karyotypes, in which the distribution of peaks represents the differences. We have analysed flow karyotypes from 9 representative squamate species and show chromosome profiles for each species based on the relationship between size and GC content. Our results reveal that the GC content of macrochromosomes is invariable in the 9 species. A higher GC content was found in microchromosomes, similar to profiles previously determined in crocodile, turtle, and chicken. The findings suggest that karyotype evolution in reptiles is characterized by unique features of chromosome GC content.
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Composición de Base/genética , Cromosomas/genética , Cariotipificación/métodos , Reptiles/genética , Animales , Evolución Molecular , Tamaño del Genoma , Filogenia , Reptiles/clasificación , Especificidad de la Especie , Secuenciación Completa del Genoma/métodosRESUMEN
Despite the variation observed in the diploid chromosome number of storks (Ciconiiformes, Ciconiidae), from 2n = 52 to 2n = 78, most reports have relied solely on analyses by conventional staining. As most species have similar macrochromosomes, some authors propose that karyotype evolution involves mainly fusions between microchromosomes, which are highly variable in species with different diploid numbers. In order to verify this hypothesis, in this study, the karyotypes of 2 species of storks from South America with different diploid numbers, the jabiru (Jabiru mycteria, 2n = 56) and the maguary stork (Ciconia maguary, 2n = 72), were analyzed by chromosome painting using whole chromosome probes from the macrochromosomes of Gallus gallus (GGA) and Leucopternis albicollis (LAL). The results revealed that J. mycteria and C. maguary share synteny within chromosome pairs 1-9 and Z. The syntenies to the macrochromosomes of G. gallus are conserved, except for GGA4, which is homologous to 2 different pairs, as in most species of birds. A fusion of GGA8 and GGA9 was observed in both species. Additionally, chromosomes corresponding to GGA4p and GGA6 are fused to other segments that did not hybridize to any of the macrochromosome probes used, suggesting that these segments correspond to microchromosomes. Hence, our data corroborate the proposed hypothesis that karyotype evolution is based on fusions involving microchromosomes. In view of the morphological constancy of the macrochromosome pairs in most Ciconiidae, we propose a putative ancestral karyotype for the family, including the GGA8/GGA9 fusion, and a diploid number of 2n = 78. The use of probes for microchromosome pairs should be the next step in identifying other synapomorphies that may help to clarify the phylogeny of this family.
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Aves/genética , Pintura Cromosómica/veterinaria , Cromosomas/genética , Variación Genética/genética , Cariotipo , Animales , Brasil , Diploidia , Evolución Molecular , Femenino , FilogeniaRESUMEN
Pigeons and doves (Columbiformes) are one of the oldest and most diverse extant lineages of birds. However, the karyotype evolution within Columbiformes remains unclear. To delineate the synteny-conserved segments and karyotypic differences among four Columbidae species, we used chromosome painting from Gallus gallus (GGA, 2n = 78) and Leucopternis albicollis (LAL, 2n = 68). Besides that, a set of painting probes for the eared dove, Zenaida auriculata (ZAU, 2n = 76), was generated from flow-sorted chromosomes. Chromosome painting with GGA and ZAU probes showed conservation of the first ten ancestral pairs in Z. auriculata, Columba livia, and Columbina picui, while in Leptotila verreauxi, fusion of the ancestral chromosomes 6 and 7 was observed. However, LAL probes revealed a complex reorganization of ancestral chromosome 1, involving paracentric and pericentric inversions. Because of the presence of similar intrachromosomal rearrangements in the chromosomes corresponding to GGA1q in the Columbidae and Passeriformes species but without a common origin, these results are consistent with the recent proposal of divergence within Neoaves (Passerea and Columbea). In addition, inversions in chromosome 2 were identified in C. picui and L. verreauxi. Thus, in four species of distinct genera of the Columbidae family, unique chromosomal rearrangements have occurred during karyotype evolution, confirming that despite conservation of the ancestral syntenic groups, these chromosomes have been modified by the occurrence of intrachromosomal rearrangements.
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Pintura Cromosómica , Columbidae/genética , Gorriones/genética , Animales , Pollos , Inversión Cromosómica , Cromosomas/genética , Evolución Molecular , Reordenamiento Génico , Humanos , Cariotipo , SinteníaRESUMEN
The involvement of chromosome changes in the initial steps of speciation is controversial. Here we examine diversification trends within the mole voles Ellobius, a group of subterranean rodents. The first description of their chromosome variability was published almost 40 years ago. Studying the G-band structure of chromosomes in numerous individuals revealed subsequent homologous, step-by-step, Robertsonian translocations, which changed diploid numbers from 54 to 30. Here we used a molecular cytogenetic strategy which demonstrates that chromosomal translocations are not always homologous; consequently, karyotypes with the same diploid number can carry different combinations of metacentrics. We further showed that at least three chromosomal forms with 2n = 34 and distinct metacentrics inhabit the Pamir-Alay mountains. Each of these forms independently hybridized with E. tancrei, 2n = 54, forming separate hybrid zones. The chromosomal variations correlate slightly with geographic barriers. Additionally, we confirmed that the emergence of partial or monobrachial homology appeared to be a strong barrier for hybridization in nature, in contradistinction to experiments which we reported earlier. We discuss the possibility of whole arm reciprocal translocations for mole voles. Our findings suggest that chromosomal translocations lead to diversification and speciation.