Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
Neotrop Entomol ; 51(3): 339-355, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35103980

RESUMEN

Anastrepha fraterculus (Wiedmann) is an important American pest species. Knowledge of its population dynamics is of particular interest for ecology, evolutionary biology, and management programs. In the present study, phenotypic, genotypic, and spatial data were combined, within the frame of landscape genetics, to uncover the spatial population genetic structure (SGS) and demographic processes of an Argentinian local population from the Yungas ecoregion. Eight simple sequence repeats (SSR) loci and six morphometric traits were analysed considering the hierarchical levels: tree/fruit/individual. Genetic variability estimates were high (HE = 0.72, RA = 4.39). Multivariate analyses of phenotypic data showed that in average 52.81% of variance is explained by the tree level, followed by between individuals 28.37%. Spatial analysis of morphological traits revealed a negative autocorrelation in all cases. SGS analysis and isolation by distance based on SSR showed no significant autocorrelation for molecular coancestry. The comparison between phenotypic (PST) and molecular (FST) differentiation identified positive selection in different fruits for all traits. Bayesian analysis revealed a cryptic structure within the population, with three clusters spatially separated. The results of this study showed a metapopulation dynamics. The genetic background of the components of this metapopulation is expected to change through time due to seasonality, repopulation activities, and high gene flow, with an estimated dispersal ability of at least 10 km. Effective population size (Ne) of the metapopulation was estimated in around 800 flies, and within subpopulations (clusters) Ne was associated with the levels of genetic drift experienced by the founding lineages.


Asunto(s)
Genética de Población , Tephritidae , Animales , Teorema de Bayes , Drosophila/genética , Variación Genética , Repeticiones de Microsatélite , Dinámica Poblacional , América del Sur , Tephritidae/genética
2.
Rev. argent. mastología ; 39(144): 39-61, sept. 2020. graf, tab
Artículo en Español | LILACS, BINACIS | ID: biblio-1150855

RESUMEN

Introducción: El cáncer de mama se clasifica en 4 subgrupos moleculares de tumores. Estos factores biológicos junto al grado histológico, han tomado importancia en la nueva clasificación TNM ya que permite establecer pronósticos de sobrevida. Objetivo: Analizar la correlación entre los distintos subtipos moleculares de los carcinomas de mama con factores clínico-patológico, la presencia de metástasis axilares y en la re-estadificación de los tumores según la nueva Clasificación TNM de la AJCC. Material y método: Estudio observacional y descriptivo de series de casos, registrados en Registro de Cáncer de Mama (RCM), en Argentina entre los años 2006 a 2016. Resultados: La mayoría de los tumores fueron Luminales. Los estadios avanzados fueron en edades tempranas. El mayor compromiso axilar perteneció a HER2 neu positivos. Se consiguió re estadificar las pacientes aumentando el número de pacientes con estadios IA y IB y descendiendo los estadios IIA, IIIA, IIIB y IIIC. Conclusiones: De los subtipos moleculares con factores clinicopatológicos más desfavorables fueron los Triples Negativos y Her2 neu. La importancia de los factores biológicos a la hora de re estadificar los pacientes según TNM 8° edición, favorece los tratamientos conservadores y específicos contra el tumor evitando el sobre tratamiento e implican menores costos que las plataformas genómcias.


Introduction: Breast cancer is classified into 4 molecular subgroups. These biological factors, together with the histological grade, are important factors in the 8th edition of the TNM Classification, and allow establishing survival prognoses in patients with breast cancer. Objetive: The main objetive was to analyse the correlation between different molecular subtypes of breast carcinomas, the presence of axillary metastases and the correlation of tumours in the new TNM Classification. Material and method: Observational and descriptive restrospective study of case series registred in RCM, in Argentina between 2006 and 2016. Results: Most of the tumours were Luminals. The clinical presentation of advanced stages was more frequent at early ages. The molecular subtypes with the highest axillary involvement were HER2 neu tumours. We managed to re-stage the patients to the TNM Classification 8th edition, increasing the number of patients with stages IA and IB and decreasing the stage IIA, IIIA, IIIB and IIIC. Conclusions: Triples negative tumours were diagnosed in more advanced stages, according to the new TNM Classification, than the Luminals. The surgical decision was not modified according to the molecular subtype. We conclude the importance of biological factors when re-staging patients according to the new TNM Classification 8th edition because it increases the number of conservative treatments, and more targets treatment.


Asunto(s)
Humanos , Femenino , Neoplasias de la Mama , Factores Biológicos , Clasificación , Metástasis de la Neoplasia , Estadificación de Neoplasias
3.
Mol Ecol Resour ; 17(6): e241-e250, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28654194

RESUMEN

The integration of ecology and genetics has become established in recent decades, in hand with the development of new technologies, whose implementation is allowing an improvement of the tools used for data analysis. In a landscape genetics context, integrative management of population information from different sources can make spatial studies involving phenotypic, genotypic and environmental data simpler, more accessible and faster. Tools for exploratory analysis of autocorrelation can help to uncover the spatial genetic structure of populations and generate appropriate hypotheses in searching for possible causes and consequences of their spatial processes. This study presents EcoGenetics, an R package with tools for multisource management and exploratory analysis in landscape genetics.


Asunto(s)
Biodiversidad , Bioestadística/métodos , Genética de Población/métodos , Análisis Espacial
4.
Am J Bot ; 104(2): 313-321, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28143832

RESUMEN

PREMISE OF THE STUDY: Gene flow through dispersal of seeds and pollen is a fundamental determinant of spatial genetic structure (SGS) in natural populations of trees at different spatial scales. Within continuous populations, restrictions to gene flow should be manifested in a process of local genetic differentiation, known as isolation by distance. The present work examines the SGS of a Prosopis alba population in a patchy region where urban, forest, and agricultural areas coexist. The analysis discussed here expands our knowledge about the processes affecting the distribution of the genetic variability in populations of disturbed landscapes. METHODS: Three sites with different landscape and demographic characteristics were analyzed. Seven highly variable microsatellite markers were used to survey the relevance of both isolation by distance and stochastic migration in the SGS of the population. KEY RESULTS: The analyses showed that (1) the genetic similarity declined with increasing geographic distance, (2) the population may be conceived as a single genetically continuous unit showing spatial differentiation as consequence of isolation by distance, rather than a structured population following the island model, and (3) there is evidence supporting a past immigration event into one of the study sites, which promoted a local pattern of genetic structure. CONCLUSIONS: These results indicate that in spite of the population fragmentation produced by land-use changes, P. alba maintains the genetic cohesion and a continuous genetic structure in the analyzed area.


Asunto(s)
Flujo Génico , Variación Genética , Prosopis/genética , Procesos Estocásticos , Argentina , Ecosistema , Frecuencia de los Genes , Genética de Población , Geografía , Repeticiones de Microsatélite , Polen/genética , Dinámica Poblacional , Prosopis/crecimiento & desarrollo , Aislamiento Reproductivo , Dispersión de Semillas/genética , Análisis de Secuencia de ADN
5.
Artículo en Español | LILACS | ID: biblio-908098

RESUMEN

El cáncer de laringe es la segunda neoplasia maligna de cabeza y cuello en adultos. Hemos decidido la búsqueda de un método diagnóstico eficaz y eficiente de las tumoraciones laríngeas sospechosas de malignidad. Se realiza la punción aspiración con aguja fina transcartilaginosa laríngea (PAAF TCL) en las lesiones laríngeas de estadios TNM altos (III y IV) como método diagnóstico alternativo a la tradicional biopsia por microcirugía laríngea. Se logra así la optimización de recursos institucionales y el beneficio de los pacientes en función del tratamiento de los mismos.


Laryngeal cancer is the second leading cause ofhead and neck malignant neoplasms in adults. Wedecided to search for effective diagnostic method oflaryngeal tumors suspicious of malignancy. Transcartilaginous Fine Needle Aspiration Biopsy (TF-NAB) is performed in laryngeal lesions of high levelTNM stage (III and IV) as an alternative to traditionalbiopsy by laryngeal microsurgery. It achievesthe optimization of institutional resources and thebenefit of patients according to their treatment.


O câncer de laringe é segunda neoplasia maligna de cabeça e pescoço em adultos. Decidimos buscar um método diagnóstico eficaz e eficiente das tumorações laríngeas com suspeitas de malignidade.Realiza-se a Punção Aspiração com Agulha Fina Transcartilaginosa Laríngea (PAAF TCL) nas lesões laríngeas de estádios TNM altos (III e IV) como método diagnóstico alternativo à tradicional biopsia por microcirurgia laríngea. Obtém-se assim a otimização de recursos institucionais e o benefício dos pacientes em função do seu tratamento.


Asunto(s)
Humanos , Biopsia con Aguja Fina/instrumentación , Biopsia con Aguja Fina/métodos , Neoplasias Laríngeas/diagnóstico , Análisis Costo-Eficiencia , Análisis Costo-Beneficio
6.
Genetica ; 131(3): 217-30, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17242965

RESUMEN

Genetic variability, population structure and differentiation among 17 populations of 5 species and 2 natural interspecific hybrids of section Algarobia of genus Prosopis were analyzed from data of 23 isozyme and 28 RAPD loci. Both markers indicated that the studied populations are highly variable. P. alba populations in average showed lower values of genetic variability estimates from isozyme data, but this trend was not observed for RAPD markers. The hierarchical analyses of the distribution of genetic variability showed that the highest proportion of variation occurred within populations, the differentiation among species was intermediate and the lowest component was observed among populations within species. The consistency between results from both dataset implies that they are not biased and reflect the actual genetic structure of the populations analyzed. The matrices of Euclidean distances obtained from the two sets of markers were highly correlated according to Mantel test. In both cases the corresponding phenogram and MDS plot tended to cluster conspecific populations while hybrid populations were not intermediate between putative parents. Some disagreements between isozyme and RAPD phenograms were observed mainly in the affinities of hybrid populations. Such inconsistencies might result from reticular rather than dichotomic evolutionary relationships. The phenetic associations retrieved gave no support to the division of the section Algarobia into series.


Asunto(s)
Genética de Población/métodos , Isoenzimas/genética , Prosopis/genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Argentina , Quimera , Flujo Génico , Frecuencia de los Genes , Variación Genética , Geografía , Modelos Genéticos , Prosopis/clasificación
7.
Genetica ; 121(1): 33-42, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15098735

RESUMEN

Prosopis species constitute a very important resource in arid and semiarid regions. Some species of section Algarobia hybridise and introgress naturally in areas of sympatry. According to previous isoenzymatic studies these species have high variability within populations. However, the genetic differentiation among species was very low, and these markers failed to provide diagnostic loci for species recognition. Here we analysed by the RAPD technique natural populations of Prosopis alba, P. ruscifolia, P. nigra, P. flexuosa, and P. vinalillo with the purpose of obtaining markers for species and hybrid identification, by analysing the distribution of genetic diversity within and among species. Genetic variability (H = 0.12-0.26) was similar in all populations. Genetic differentiation among populations (FST = 0.39) was highly significant. Hierarchical analysis of genetic structure performed by Wright (1978) method and analysis of molecular variance (AMOVA) indicated that the diversity among populations within species is low (4-13%) and most genetic diversity (54-61%) occurs within populations. The differentiation among species is intermediate (26-42%) between the previous components but highly significant. Five bands provided a tool for identifying any of the species studied, with the exception of P. vinalillo. The difficulty in diagnosing this species is discussed in reference to the hypothesis of its hybrid origin.


Asunto(s)
Variación Genética , Prosopis/genética , Técnica del ADN Polimorfo Amplificado Aleatorio/métodos , Argentina , Frecuencia de los Genes , Marcadores Genéticos , Genética de Población , Geografía , Filogenia , Prosopis/clasificación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...