Video Experimental Relacionado
Updated: Jul 10, 2026
10:17
An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations
Published on: November 3, 2010
Expresión monoalélica extendida en los autosomas humanos
Alexander Gimelbrant1, John N Hutchinson, Benjamin R Thompson
1Center for Human Genetic Research and Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Simches Research Building, 185 Cambridge Street, Boston, MA 02114, USA.
Science (New York, N.Y.)
|November 17, 2007
Resumen
La expresión génica monoalélica aleatoria, donde solo una de las dos copias de genes parentales está activa, es más común de lo que se pensaba. Este hallazgo en células humanas sugiere un nuevo mecanismo para generar diversidad celular.
Área de la Ciencia:
- Genética y Genómica.
- Biología Molecular Biología Molecular
- La epigenética es la epigenética.
Sus antecedentes:
- La expresión génica monoalélica, que implica la selección aleatoria del alelo materno o paterno, es una característica conocida de los genes inactivados con X y de ciertas familias de genes autosómicos.
- Comprender la prevalencia y los mecanismos de la expresión monoalélica es crucial para comprender la regulación génica y la heterogeneidad celular.
Objetivo del estudio:
- Realizar una evaluación de todo el genoma de la transcripción específica de alelos en células humanas para identificar genes que exhiben expresión monoalélica aleatoria.
- Investigar el alcance de la expresión monoalélica aleatoria a través de un gran conjunto de genes humanos y sus implicaciones para la diversidad celular.
Principales métodos:
- Utilizó un enfoque de todo el genoma para analizar la transcripción específica del alelo.
- Examinó aproximadamente 4000 genes humanos en líneas celulares clonales para identificar patrones de expresión monoalélica y bialélica.
Principales resultados:
- Identificó más de 300 genes humanos que están sujetos a la expresión monoalélica aleatoria.
- Se observó que la mayoría de estos genes monoalélicos también exhibieron expresión bialélica en algunas líneas celulares clonales, lo que indica opciones alélicas independientes.
- Se demostró que la expresión monoalélica aleatoria puede conducir a variaciones en las secuencias de proteínas expresadas y los niveles de expresión génica entre las células.
Conclusiones:
- La ocurrencia generalizada de la expresión monoalélica aleatoria sugiere que es un mecanismo biológico significativo.
- Este fenómeno probablemente contribuye a generar diversidad funcional dentro de las células individuales y sus descendientes clonales.
- Se requiere más investigación para dilucidar los mecanismos moleculares precisos que subyacen a esta expresión monoalélica aleatoria generalizada.
Videos de Conceptos Relacionados
01:35Pedigree Analysis
Overview
02:30Genomic Imprinting and Inheritance
Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes.
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
01:33Pleiotropy
Pleiotropy is the phenomenon in which a single gene impacts multiple, seemingly unrelated phenotypic traits. For example, defects in the SOX10 gene cause Waardenburg Syndrome Type 4, or WS4, which can cause defects in pigmentation, hearing impairments, and an absence of intestinal contractions necessary for elimination. This diversity of phenotypes results from the expression pattern of SOX10 in early embryonic and fetal development. SOX10 is found in neural crest cells that form melanocytes,...
02:19The Y Chromosome Determines Maleness
The Y chromosome is a sex chromosome found in several vertebrates and mammals, including humans. In addition to 22 pairs of autosomes, the human males have one X chromosome and one Y chromosome. In these organisms, the presence or absence of the Y chromosome determines the development of male traits.
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size. Today,...
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size. Today,...
02:45The Ratio of X Chromosome to Autosomes
In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies.
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
01:19X-linked Traits
In most mammalian species, females have two X sex chromosomes and males have an X and Y. As a result, mutations on the X chromosome in females may be masked by the presence of a normal allele on the second X. In contrast, a mutation on the X chromosome in males more often causes observable biological defects, as there is no normal X to compensate. Trait variations arising from mutations on the X chromosome are called “X-linked”.