Actualmente la Genética ha ocupado un papel central en la comprensión de los procesos biológicos, debido a que, de manera recurrente, los conocimientos genéticos auxilian a las demás ramas de la ...Biología en la explicación de los fenómenos que ellas estudian. Este hecho ha conllevado a la necesaria integración interdisciplinaria en la enseñanza de la Genética, con el fin de propiciar un enfoque sistémico en el estudio, la impartición y la comprensión de los procesos en que están involucrados los genes. Tradicionalmente, en la impartición del tema relacionado con la transmisión de los caracteres de las plantas de guisante investigados por Mendel, ha primado un enfoque historicista y reproductivo de los cruzamientos realizados por él, sin abordar aspectos morfo-fisiológicos, metabólicos y genético-moleculares, de esos caracteres. Este enfoque aún prevalece en determinados centros de educación superior. El presente artículo tiene como objetivo, fundamentar una propuesta más integradora y actual para la impartición del tema: "Leyes de Mendel". La misma, además de manejar el término "factores hereditarios" como entidades abstractas, en la explicación de los experimentos realizados por Mendel, considera también la caracterización molecular actual de estas entidades como "genes". Incluir la información antes mencionada en la enseñanza de los cursos de Genética sería una contribución significativa en la formación de especialistas y en el perfeccionamiento de la asignatura. Con tal fin, se recomienda una enseñanza más completa y actualizada de los caracteres estudiados por Mendel. Se proporcionan ejemplos concretos y se hace referencia a los conceptos genéticos que permiten lograr el enfoque propuesto en el desarrollo de conferencias, clases prácticas y seminarios. Hoy es factible la enseñanza de la Genética con la perspectiva del pensamiento sistémico, el arsenal de conocimiento acumulado por las Ciencias Biológicas así lo permite. La integración de contenidos de nivel de organismo y nivel molecular, en determinados temas de los programas de Genética, contribuirá a una representación más consistente del papel que juegan los genes como parte de la materia viva.
Gregor Mendel’s discovery of the laws of segregation and independent assortment and his inference of the existence of non-mendelian interactions between loci remain at the heart of today’s ...explorations of the genetic architecture of quantitative traits.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We report the first annotated chromosome-level reference genome assembly for pea, Gregor Mendel's original genetic model. Phylogenetics and paleogenomics show genomic rearrangements across legumes ...and suggest a major role for repetitive elements in pea genome evolution. Compared to other sequenced Leguminosae genomes, the pea genome shows intense gene dynamics, most likely associated with genome size expansion when the Fabeae diverged from its sister tribes. During Pisum evolution, translocation and transposition differentially occurred across lineages. This reference sequence will accelerate our understanding of the molecular basis of agronomically important traits and support crop improvement.
Johann Gregor Mendel, born 200 years ago, was supposed to be a farmer, intended to be a teacher, became a priest, turned to being a researcher, and later became a world famous scientist associated ...with genetics. Here, we look into his life through his own words.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Exceptions to Mendel’s law of segregation were important for demonstrating that chromosomes carry genetic material. Scrutiny of additional exceptions to Mendel’s law caused by selfish genes has the ...potential to unravel other unsolved mysteries of genetics.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
By following the evolution of populations that are initially genetically homogeneous, much can be learned about core biological principles. For example, it allows for detailed studies of the rate of ...emergence of de novo mutations and their change in frequency due to drift and selection. Unfortunately, in multicellular organisms with generation times of months or years, it is difficult to set up and carry out such experiments over many generations. An alternative is provided by "natural evolution experiments" that started from colonizations or invasions of new habitats by selfing lineages. With limited or missing gene flow from other lineages, new mutations and their effects can be easily detected. North America has been colonized in historic times by the plant Arabidopsis thaliana, and although multiple intercrossing lineages are found today, many of the individuals belong to a single lineage, HPG1. To determine in this lineage the rate of substitutions-the subset of mutations that survived natural selection and drift-, we have sequenced genomes from plants collected between 1863 and 2006. We identified 73 modern and 27 herbarium specimens that belonged to HPG1. Using the estimated substitution rate, we infer that the last common HPG1 ancestor lived in the early 17th century, when it was most likely introduced by chance from Europe. Mutations in coding regions are depleted in frequency compared to those in other portions of the genome, consistent with purifying selection. Nevertheless, a handful of mutations is found at high frequency in present-day populations. We link these to detectable phenotypic variance in traits of known ecological importance, life history and growth, which could reflect their adaptive value. Our work showcases how, by applying genomics methods to a combination of modern and historic samples from colonizing lineages, we can directly study new mutations and their potential evolutionary relevance.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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