36,114 research outputs found

    Revisão taxonómica do género Calendula L. (Asteraceae - Calenduleae) na Península Ibérica e Marrocos

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    The genus Calendula L. (Asteraceae - Calenduleae) includes, depending on the author, 10 to 25 species, distributed mainly in the Mediterranean basin. The taxonomy of this genus is considered to be extremely difficult, due to a great morphological variability, doubtfull relevance of some of the characters used to distinguish its species (e.g. the life form: annual or perennial; the habit: erect or diffuse, shape of the leaves, indumentum, relative size of the capitula and colour of disc or ray florets, achene morphology), but also due to the hybridization and polyploidization. Despite the numerous studies that have been published, no agreement on the classification and characters used to discriminate between taxa has been reached. A taxonomic study of the genus Calendula was conducted for the Iberian Peninsula and Morocco, aiming at (1) access the morphological variability between and within taxa, (2) confirm the chromosome numbers, (3) increase the nuclear DNA content estimations, (4) re-evaluate taxa delimitations and circumscription, and (5) reassess, and redefine, the descriptions and characters useful to distinguish taxa. In order to achieve a satisfying taxonomic core, extensive fieldwork, detailed morphometric analysis, chorological, karyological and genome size studies were conducted. For the Iberian Peninsula, four species were recognized, including nine subspecies (between these two new subspecies were described). For Morocco, including some taxa from Algeria and Tunisia 13 species were recognized (two new species and a nomenclatural change), including 15 subspecies (among these eight new subspecies were described). To corroborate the results obtained and to evaluate the evolutionary relationships among taxa, phylogenetic studies using molecular methods, such as ITS, microsatellites or other molecular markers, should be used.O g√©nero Calendula L. (Asteraceae - Calenduleae) inclui, dependendo do autor, 10 a 25 esp√©cies, distribu√≠das essencialmente na bacia do Mediterr√Ęneo. A taxonomia deste g√©nero √© considerada extremamente dif√≠cil, devido √† grande variabilidade morfol√≥gica, discutivel relev√Ęncia de alguns dos caracteres utilizados para distinguir suas esp√©cies (por exemplo, a forma de vida: anual ou perene, o h√°bito: erecto ou difuso, a forma das folhas, o indumento, o tamanho e a cor dos cap√≠tulos e a morfologia dos aqu√©nios), mas tamb√©m devido √† hibridiza√ß√£o e poliploidiza√ß√£o. Apesar dos in√ļmeros estudos que foram publicados, n√£o foi alcan√ßado um acordo sobre a classifica√ß√£o e os caracteres utilizados para discriminar as suas esp√©cies. Um estudo taxon√≥mico do g√©nero Calendula foi realizado para a Pen√≠nsula Ib√©rica e Marrocos, com o objectivo de (1) verificar a variabilidade morfol√≥gica, (2) confirmar o n√ļmero de cromossomas, (3) aumentar as estimativas de conte√ļdo em ADN, (4) reavaliar a delimita√ß√£o e a circunscri√ß√£o dos taxa, e (5) reavaliar e redefinir as descri√ß√Ķes e caracteres √ļteis para os distinguir. Para alcan√ßar uma robust√™s taxon√≥mica satisfat√≥ria, foram realizados extensos trabalhos de campo, an√°lise morfom√©trica detalhada, abordagens corol√≥gicas, cariol√≥gicas e quanto ao conte√ļdo em ADN. Para a Pen√≠nsula Ib√©rica, quatro esp√©cies foram reconhecidas, incluindo nove subesp√©cies (entre essas duas novas subesp√©cies foram descritas). Para Marrocos, incluindo alguns taxa da Argelia e Tunisia, foram reconhecidas 13 esp√©cies (duas novas e uma mudan√ßa nomenclatural), incluindo 15 subesp√©cies (entre essas oito novas subesp√©cies foram descritas). Para corroborar os resultados obtidos e avaliar as rela√ß√Ķes evolutivas e filogen√©ticas entre os taxa, estudos que utilizem diferentes m√©todos moleculares, tais como ITS, microsat√©lites ou outros marcadores moleculares, devem ser utilizados.Apoio financeiro do Laborat√≥rio Associado CESAM - Centro de Estudos do Ambiente e do Mar (AMB/50017) financiado por fundos nacionais atrav√©s da FCT/MCTES e cofinanciado pelo FEDER (POCI-01-0145-FEDER-007638), no √Ęmbito do Acordo de Parceria PT2020, e Compete 2020Programa Doutoral em Biologi

    Genetic variation within and relationships among five subpopulations of Slovak Thoroughbred

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    Genetic variation at six microsatellite loci was analysed for five Thoroughbred subpopulations to determine the magnitude of genetic differentiation and the genetic relationships among the subpopulations. Significant deviations from Hardy-Weinberg equilibrium were shown for a number of locus-population combinations, with all subpopulations. The genetic diversities and relationships of five Thoroughbred subpopulations were evaluated using six microsatellites recommended by the International Society of Animal Genetics (ISAG). The allele frequencies, the effective numbers of alleles, and the observed and expected heterozygosities were calculated. POPGENE v. 1.31 (Yeh et al., 1997) was used to test for deviations from the Hardy-Weinberg (H-W) equilibrium and to assign FIS estimates (Weir, 1990). The utility of microsatellites for evaluating genetic diversity of horses is discussed

    Sandfish generations: loss of genetic diversity due to hatchery practices in the sea cucumber Holothuria (Metriatyla) scabra

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    Hatcheries are indispensable for seed production of many commercial aquaculture species. However, for mass-spawning species in particular, they can be capricious environments where genetic diversity among progeny may be lost due to small effective broodstock population sizes, variable parental contributions and differential family survival. Understanding the genetic impacts of hatchery production is therefore important for addressing these problems and optimising propagation methods. We used 6051 genome-wide Single Nucleotide Polymorphisms (SNPs) to analyse genetic diversity, parental contributions and offspring kinship during a commercial-scale hatchery production run of sandfish (Holothuria scabra), a high-value sea cucumber grown in mariculture operations across the Indo-Pacific region. Broodstock contributions were highly skewed, with up to 26% of the parent pool contributing and kinship analyses determined that just two parents sired between 44.4 and 67.5% of all offspring genotyped. Effective population sizes were reduced as expected between broodstock and offspring groups (NeLD = 1121.2 vs. 19.4, respectively), while losses of allelic diversity but not overall heterozygosity were apparent. Numbers of families surviving (13‚Äď16) to the juvenile stage were low, suggesting low effective population sizes among offspring cohorts is an issue for sandfish hatchery operations. To address variability in family compositions and broodstock contributions, pedigree tracking and batch spawning may be used to optimize broodstock management and hatchery protocols, to ensure production of genetically diverse offspring for routine culture and restocking operations. As many sandfish broodstock remain wild-sourced, maintenance of healthy wild populations as reservoirs of genetic diversity is important, along with selection for spawning of genetically diverse individuals which are as distantly-related as possible

    Deep space orbit determination and guidance of the LICIACube microsatellite mission

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    Recently, the JPL's MarCO mission demonstrated that these probes are also mature enough to be employed in the deep space, even though with the limitations related to the employed commercial components. Currently, other deep space CubeSats are planned either as stand-alone missions or as companions of a traditional large probe. Therefore, developing a dedicated navigation suite is crucial to reaching the mission's goals, considering the limitations of the onboard components compared to typical deep space missions. In this framework, the LICIACube mission represents an ideal candidate test-bench, as it performs a flyby of the Didymos asteroid system subject to a strong position, epochs, and pointing requirements. This mission will also allow us to infer the capabilities of such microsatellites and highlight their limitations compared with the benefits of a lighter design and tailoring efforts. In this work, the OD and guidance methods and tools adopted for classical deep space missions have been tailored for the CubeSat applications and validated through extensive analyses. In addition, navigation procedures and interfaces have been designed in view of the operations foreseen in late 2022. The pre-launch covariance analysis has been performed to assess the mission's feasibility for the nominal trajectory and its associated uncertainties, based on conservative assumptions on the main parameters. Extensive sensitivity analyses have been carried out to understand the main mission parameters affecting the performance and to demonstrate the robustness of the designed trajectory and operation schedule in fulfilling the mission requirements. The developed system was also stressed by tuning the models to access different reconstruction methods for the maneuvers. The analysis demonstrated the feasibility of the LICIACube mission navigation in compliance with the mission requirements, compatible with the limited resources available, both in space and on the ground

    Parámetros genéticos de los caracteres morfológicos lineales de la raza caprina murciano-granadina y sus relaciones con otros caracteres funcionales

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    Linear appraisal systems (LAS) are effective strategies for systematically collecting zoometric information from animal populations. Traditionally applied LAS in goats was developed considering the variability and scales found in highly selected breeds. Implementing LAS may reduce time, personnel, and resource needs when performing zoometric large-scale collection. Moreover, selection for zoometrics defines individuals‚Äô productive longevity, endurance, enhanced productive abilities, and consequently, long-term profitability. As a result, traditional LAS may no longer cover the different contexts of goat breeds widespread throughout the world, and departures from normality may be indicative of the different stages of selection at which a certain population can be found. In the first study, an evaluation of the distribution and symmetry properties of twenty-eight zoometric traits was developed. After symmetry analysis was performed, the scale readjustment proposal suggested specific strategies should be implemented such as scale reduction of lower or upper levels, determination of a setup moment to evaluate and collect information from young (up to 2 years) and adult bucks (over 2 years), the addition of upper categories in males due to upper values in the scale being incorrectly clustered together. Thus, the particular analysis of each variable permits determining specific strategies for each trait and serve as a model for other breeds, either selected or in terms of selection. The aim of the second study was to propose a method to optimize and validate LAS in opposition to traditional measuring protocols routinely implemented in Murciano-Granadina goats. The data sample consisted of 41323 LAS and traditional measuring records, belonging to 22727 herdbook registered primipara does, 17111 multipara does, and 1485 bucks. Each record comprised information on 17 linear traits for primipara and multipara does, and 10 traits for bucks. All zoometric parameters were scored on a 9-points scale. Cronbach‚Äôs alpha values suggested a high internal consistency of the optimized variable panel. Model fit, variability explanation power, and predictive power (MSE, AIC/AICc, and BIC, respectively) suggested a model comprising zoometric LAS scores performed better than traditional zoometry. Optimization procedures result in reduced models able to capture variability for dairy-related zoometric traits without noticeable detrimental effects on model validity properties. The third study aimed to perform a particular analysis of each variable that permits determining specific strategies for each trait and serves as a model for other breeds. Among the strategies proposed are the reduction/readjustment of the levels in the scale as it happens for limb-related traits, the extension of the scale as it occurs in the stature of males, or the subdivision of the scale used in males into two categories, bucks younger than two years and bucks of two years old and older. Murciano- Granadina goat breed has drifted towards better dairy-linked conformation traits but without losing the grounds of the zoometric basis which confers it with enhanced adaptability to the environment. Hence, such strategies can help to achieve a better understanding of the momentum of selection for dairy-linked zoometric traits in Murciano-Granadina population and their future evolution to enhance the profitability and efficiency of breeding plans. The objective of the fourth study was to evaluate the progress of heritabilities of the traits comprising the linear appraisal system in the Murciano-Granadina breed during the complete decade from December 2011 to December 2021. The estimated values for heritability were obtained from multivariate analyzes using the BLUP methodology and MTDFREML software. For 2021 heritabilities, a simple animal model was applied to records collected from 22727 primiparous goats and 17111 multiparous goats belonging to 85 herds. The model included the linear and quadratic and linear components of the covariates age and days in milk, respectively. The fixed effects considered in the model were herd, reproductive status, calving month, and herd/year interaction. The animal was considered as a random effect. The variables studied included five characteristics related to structure and capacity, two traits related to dairy structure, six related to the mammary system, and three related to legs and feet. The heritabilities for structure and capacity characters progressed from 0.22 to 0.28 including non-convergent variables in June 2012 to values between 0.10 and 0.41 with all variables converging in June 2021. Heritabilities for dairy structure progressed from 0.18 with nonconvergent variables in 2011 to 0.17 to 0.25 in 2021. Heritabilities for mammary system traits progressed from 0.12 to 0, 27 with non-convergent variables in 2012 to between 0.10 and 0.41 in 2021. For legs and feet, heritabilities progressed from 0.16 to 0.17 with non-convergent variables to 0.09 a 0.22. Genetic progress is not only evident in heritability values, but there has been a notable reduction in the standard error of heritabilities from 0.1000 (0.080-0.120) to 0.000 (0.000-0.001) from 2011 to 2021. These results provide evidence of the enhancement in the effectiveness and precision of the linear qualification system applied during the past decade and its successful integration into the breeding program of the Murciano- Granadina breed. The fifth study estimates genetic and phenotypic parameters for zoometric/LAS traits in Murciano-Granadina goats, estimate genetic and phenotypic correlations among all traits, and to determine whether major area selection would be appropriate or if adaptability strategies may need to be followed. Heritability estimates for the zoometric/LAS traits were low to high, ranging from 0.09 to 0.43 and the accuracy of estimation has improved after decades rendering standard errors negligible. Scale inversion of specific traits may need to be performed before major areas selection strategies are implemented. Genetic and phenotypic correlations suggest that negative selection against thicker bones and higher rear insertion heights, indirectly results in the optimization of selection practices in the rest of the traits, especially of those in the structure and capacity and mammary system major areas. The integration and implementation of the strategies proposed within Murciano-Granadina breeding program maximize selection opportunities and the sustainable international competitiveness of the Murciano- Granadina goat in the dairy goat breed panorama. The objective of the sixth study was to develop a discriminant canonical analysis (DCA) tool that permits outlining the role of the individual haplotypes of each component of the casein complex (őĪS1, ő≤, őĪS2, and őļ-casein) on zoometrics/linear appraisal breeding values. The relationship of the predicted breeding value for 17 zoometric/Linear appraisal traits and őĪS1, ő≤, őĪS2, and őļ-casein genes haplotypic sequences was assessed. Results suggest that, although a lack of significant differences (P>0.05) was reported across the predictive breeding values of zoometric/linear appraisal traits for őĪS1, őĪS2 and őļ casein, significant differences were found for ő≤ Casein (P0,05) en los valores de cr√≠a predichos de los rasgos de zoometr√≠a/calificaci√≥n lineal para la őĪS1, őĪS2 y őļ-case√≠na, se encontraron diferencias significativas para la ő≤-case√≠na (P<0,05), respectivamente. La presencia de secuencias haplot√≠picas de ő≤-case√≠na GAGACCCC, GGAACCCC, GGAACCTC, GGAATCTC, GGGACCCC, GGGATCTC y GGGGCCCC, vinculadas a combinaciones diferenciales de mayores cantidades de leche de mayor calidad en t√©rminos de su composici√≥n, tambi√©n puede estar relacionada con una mayor valoraci√≥n zoom√©trica/lineal de la predicci√≥n de los valores de cr√≠a. La selecci√≥n debe realizarse con cuidado, dado que la consideraci√≥n de animales aparentemente deseables que presentan la secuencia haplot√≠pica GGGATCCC en el gen de la ő≤- case√≠na, debido a sus valores gen√©ticos predichos positivos para ciertos rasgos de zoometr√≠a/calificaci√≥n lineal, como la altura de la inserci√≥n trasera, la calidad √≥sea , la inserci√≥n anterior, la profundidad de ubre, la vista lateral de patas traseras y la vista trasera de patas traseras pueden conducir a una selecci√≥n indirecta frente al resto de rasgos de zoometr√≠a/calificaci√≥n lineal y a su vez conducir a una selecci√≥n ineficiente hacia un tipo morfotipo lechero √≥ptimo en cabras Murciano-Granadina. Por el contrario, la consideraci√≥n de animales que presentan la secuencia haplot√≠pica GGAACCCC implica tambi√©n considerar animales que aumentan el potencial gen√©tico para todos los rasgos de zoometr√≠a/calificaci√≥n lineal, haci√©ndolos as√≠ recomendables como reproductores. La informaci√≥n derivada de los presentes an√°lisis mejorar√° la selecci√≥n de individuos reproductores que busquen un tipo lechero bastante deseable, a trav√©s de la determinaci√≥n de las secuencias haplot√≠picas que presentan en el locus ő≤-case√≠na. Todos estos estudios persiguen la obtenci√≥n de un conocimiento m√°s profundo de los caracteres morfol√≥gicos lineales de la raza caprina Murciano-Granadina y sus relaciones con otras caracter√≠sticas funcionales. Esto sienta las bases para estrategias de normalizaci√≥n y mejora de la capacidad productiva y el morfotipo lechero de la cabra Murciano-Granadina y ayudar√° a alcanzar su consolidaci√≥n competitiva en el panorama caprino lechero internacional

    Mining alleles for tar spot complex resistance from CIMMYT's maize Germplasm Bank

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    The tar spot complex (TSC) is a devastating disease of maize (Zea mays L.), occurring in 17 countries throughout Central, South, and North America and the Caribbean, and can cause grain yield losses of up to 80%. As yield losses from the disease continue to intensify in Central America, Phyllachora maydis, one of the causal pathogens of TSC, was first detected in the United States in 2015, and in 2020 in Ontario, Canada. Both the distribution and yield losses due to TSC are increasing, and there is a critical need to identify the genetic resources for TSC resistance. The Seeds of Discovery Initiative at CIMMYT has sought to combine next-generation sequencing technologies and phenotypic characterization to identify valuable alleles held in the CIMMYT Germplasm Bank for use in germplasm improvement programs. Individual landrace accessions of the ‚ÄúBreeders' Core Collection‚ÄĚ were crossed to CIMMYT hybrids to form 918 unique accessions topcrosses (F1 families) which were evaluated during 2011 and 2012 for TSC disease reaction. A total of 16 associated SNP variants were identified for TSC foliar leaf damage resistance and increased grain yield. These variants were confirmed by evaluating the TSC reaction of previously untested selections of the larger F1 testcross population (4,471 accessions) based on the presence of identified favorable SNPs. We demonstrated the usefulness of mining for donor alleles in Germplasm Bank accessions for newly emerging diseases using genomic variation in landraces

    DataSheet3_Genetic diversity and structure of Brycon henni in regulated and non-regulated water flow rivers of the Colombian Andes.PDF

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    The sabaleta, Brycon henni, is a medium-size fish species found in the Andean range of the Magdalena-Cauca river basin in Colombia, where it is a fishery resource. Recruitment of sabaleta has affected construction of dams with unknown consequences on its genetic diversity and structure. Understanding the current genetic architecture in the dam-influenced areas compared to non-regulated water flow systems is crucial to diagnose the impact of human interventions and formulate proper management strategies. In this study, we evaluated the genetic structure and diversity of B. henni by using a set of microsatellites in individuals from 14 localities to identify the number of distinct genetic pools. We used various approaches to compare populations between regulated and non-regulated areas in the Magdalena-Cauca basin, and identified eleven well-differentiated and highly diverse population groups with marked genetic structures at local and regional levels. Genetic diversity of B. henni was very similar among non-regulated and dam-regulated water flow areas; however, one of the populations in non-regulated areas showed evidence of a founder effect associated with recent introductions. The effect of dams on the genetic structure of B. henni in the Magdalena-Cauca basin was negligible, probably due to their recent construction. Future reduction of genetic diversity and the loss of unique populations is expected due to the combined effect of geographic isolation and population declines. Thus, monitoring programs are necessary to detect changes in the genetic structure of fish populations to develop useful conservation actions.</p

    Nuclear shape instability caused by lamin A deregulation promotes invasiveness in pediatric bone sarcomas: from nucleo-cytoskeleton dynamics to novel therapeutic opportunities

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    Osteosarcoma (OS) and Ewing sarcoma (EWS) are the two most frequent primary bone tumors, in which metastases remain the most relevant adverse prognostic factor. Lamin A is the main constituent of the nuclear lamina, with a fundamental role in maintaining the connection between nucleus and cytoskeleton (through LINC complex proteins interactions), and its alterations can be implicated in tumor progression. We investigated how nucleo-cytoskeleton dynamics is influenced by lamin A modulation in OS and EWS, demonstrating that both these cancer models had low levels of lamin A, which are linked to a significantly more marked nuclear misshaping. In our in vitro studies, reduced levels of lamin A promoted migratory abilities in these tumors. Moreover, these findings were corroborated by gene expression analyses on EWS patient samples, showing that LMNA levels were significantly lower in metastatic lesions compared to primary tumors and that patients with low LMNA had a significant worse overall survival. We also found that LMNA expression significantly impaired EWS metastases formation in vivo. We demonstrated that low lamin A expression was linked to a severe mislocalization of LINC complex proteins, thus disrupting nucleo-cytoskeleton interactions, with a corresponding gain in malignant properties, which resulted in increased invasiveness. Lamin A overexpression or its accumulation by a statin-based pharmacological treatment allowed us to reconstitute a functional nucleo-cytoskeleton interplay, which resulted in significant downmodulation of ROCK2 and YAP, two crucial drivers of EWS aggressiveness. Our study demonstrated that lamin A is a favorable mediator of nuclear shape stability in bone sarcomas, and its modulation rescues LINC complex protein localization and regulates mechano-signaling pathways, thus promoting a less aggressive cancer phenotype. We also identified statins, already employed in clinical practice, as a tool capable to increase lamin A levels, and to reconstitute functional nucleo-cytoskeletal dynamics, resulting in reduced cellular migration

    The First GECAM Observation Results on Terrestrial Gamma-ray Flashes and Terrestrial Electron Beams

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    Gravitational-wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) is a space-borne instrument dedicated to monitoring high-energy transients, including Terrestrial Gamma-ray Flashes (TGFs) and Terrestrial Electron Beams (TEBs). We implemented a TGF/TEB search algorithm for GECAM, with which 147 bright TGFs, 2 typical TEBs and 2 special TEB-like events are identified during an effective observation time of ‚ąľ\sim9 months. We show that, with gamma-ray and charged particle detectors, GECAM can effectively identify and distinguish TGFs and TEBs, and measure their temporal and spectral properties in detail. A very high TGF-lightning association rate of ‚ąľ\sim80\% is obtained between GECAM and GLD360 in east Asia region.Comment: The paper was accepted by Geophysical Research Letters on June 16th, 202
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