Video Experimental Relacionado

Updated: Apr 30, 2026

Chromatin Immunoprecipitation Assay for Tissue-specific Genes using Early-stage Mouse Embryos

Chromatin Immunoprecipitation Assay for Tissue-specific Genes using Early-stage Mouse Embryos

Published on: April 29, 2011

Los nucleosomas están por fases a lo largo del gen de globina beta mayor del ratón en las células eritroides y no

R Benezra, C R Cantor, R Axel

|March 14, 1986

Resumen

Los nucleosomas se posicionan con precisión a lo largo del gen de globina beta mayor del ratón. En las células activas, esta matriz de nucleosomas en fase se interrumpe cerca del extremo 5' del gen, lo que indica estados estructurales distintos.

Área de la Ciencia:

Biología Molecular Biología Molecular
La epigenética es la epigenética.
La genómica es la genómica.

Sus antecedentes:

El posicionamiento de los nucleosomas es crucial para la regulación génica.
El gen de globina beta mayor del ratón sirve como modelo para estudiar la activación génica en las células eritroides.

Objetivo del estudio:

Para determinar la ubicación precisa y la disposición de los nucleosomas a lo largo del gen de globina beta mayor del ratón.
Para investigar cómo el posicionamiento de los nucleosomas difiere entre los estados celulares inactivos y activos.

Principales métodos:

Se utilizó el reactivo químico de escisión methidiumpropyl-EDTA-Fe ((II) (MPE-Fe ((II)) para el mapeo de nucleosomas.
Se analizó la distribución de los nucleosomas en células L de ratón (no tiroides) y en células de eritroleucemia murina (eritroides).

Principales resultados:

En las células L inactivas de ratón, los nucleosomas están precisamente por fases a través de la región del gen globina (-3000 a +1500).
Tanto en las células de eritroleucemia no inducida como en las inducidas, esta fase se mantiene pero se interrumpe entre las posiciones -200 y +500.
Esta región empobrecida de nucleosomas en las células activas está protegida de la digestión de MPE-Fe (II) y está flanqueada por sitios hipersensibles.

Conclusiones:

El gen de globina beta mayor del ratón existe en al menos dos estados estructurales distintos basados en la organización de los nucleosomas.
Un estado inactivo presenta una serie continua de nucleosomas en fase.
Un estado activo se caracteriza por una interrupción de esta matriz en la región 5' del gen.

Más Videos Relacionados

Mouse Fetal Liver Culture System to Dissect Target Gene Functions at the Early and Late Stages of Terminal Erythropoiesis

Mouse Fetal Liver Culture System to Dissect Target Gene Functions at the Early and Late Stages of Terminal Erythropoiesis

Published on: September 9, 2014

Direct Lineage Reprogramming of Adult Mouse Fibroblast to Erythroid Progenitors

Direct Lineage Reprogramming of Adult Mouse Fibroblast to Erythroid Progenitors

Published on: December 14, 2018

Videos de Conceptos Relacionados

The Nucleosome Core Particle

The Nucleosome Core Particle

Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...

Euchromatin

Euchromatin

The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions take up more dye, appearing darker, while the less-compact areas take up less dye and appear lighter. Based on the compaction level, chromatins are classified into two primary forms – euchromatin and heterochromatin.
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...

Chromatin Position Affects Gene Expression

Chromatin Position Affects Gene Expression

Chromatin is the massive complex of DNA and proteins packaged inside the nucleus. The complexity of chromatin folding and how it is packaged inside the nucleus greatly influences access to genetic information. Generally, the nucleus' periphery is considered transcriptionally repressive, while the cell's interior is considered a transcriptionally active area.
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the...

The Nucleolus

The Nucleolus

The nucleolus is the most prominent substructure of the nucleus. When it was first discovered, it was considered to be an isolated organelle that forms fibrils and granules. In 1931, the relationship between the nucleolus and chromosomes was first described by Heitz. He observed that the appearance and size of nucleolus varies depending on the stage of the cell cycle. He also noticed constricted regions on different chromosomes clustered together at definite cell cycle stages. These regions,...

General Transcription Factors

General Transcription Factors

Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...

The Nucleosome Core Particle

The Nucleosome Core Particle

Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...