Video Experimental Relacionado
Updated: Feb 9, 2026
02:31
Phase Transitions and Effect of Intermolecular Forces
23.3K
Activación genética inadecuada en la FSHD: un complejo represor se une a una repetición cromosómica eliminada en el
Davide Gabellini1, Michael R Green, Rossella Tupler
1Howard Hughes Medical Institute, Program in Gene Function and Expression, Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.
Cell
|August 15, 2002
Resumen
La distrofia muscular faccioscapulohumeral (FSHD) está relacionada con las deleciones D4Z4 en el cromosoma 4. Esta deleción hace que los genes 4q35 se sobreexpriman, lo que podría conducir a esta enfermedad muscular.
Área de la Ciencia:
- Genética La genética.
- Biología Molecular Biología Molecular
- Neurología Neurología.
Sus antecedentes:
- La distrofia muscular facioscapulohumeral (FSHD) es una miopatía autosómica dominante común con una causa molecular desconocida.
- La mayoría de los pacientes con FSHD presentan deleciones en las repeticiones en tándem D4Z4 en el cromosoma 4q35.5.
Objetivo del estudio:
- Para investigar el mecanismo molecular subyacente FSHD.
- Determinar el papel funcional de las deleciones repetidas de D4Z4 en la patogénesis de la FSHD.
Principales métodos:
- Análisis de la expresión génica en el tejido muscular FSHD.
- Ensayos de unión in vitro e in vivo para estudiar las interacciones proteína-ADN.
- Identificación de las proteínas que interactúan con el elemento D4Z4.
Principales resultados:
- Los genes anteriores a D4Z4 en el cromosoma 4q35 están inadecuadamente sobreexpresados en el músculo FSHD.
- Un complejo multiproteínico (YY1, HMGB2, nucleolina) se une a un elemento dentro de D4Z4.4.
- Este complejo media la represión transcripcional de los genes 4q35, y su unión es interrumpida por deleciones D4Z4.
Conclusiones:
- Las deleciones de D4Z4 en FSHD interrumpen la unión de un complejo represor de la transcripción.
- Esta interrupción conduce a la desrepresión inapropiada de los genes 4q35, causando FSHD.
- Los hallazgos proporcionan una base molecular para la patogénesis de FSHD.
Videos de Conceptos Relacionados
02:31Phase Transitions
23.3K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
23.3K
02:58Properties of Transition Metals
30.0K
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
30.0K
01:58Cooperative Allosteric Transitions
8.8K
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
8.8K
02:39Phase Transitions: Vaporization and Condensation
21.5K
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
21.5K
02:33Phase Transitions: Sublimation and Deposition
20.3K
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
20.3K
02:39Phase Transitions: Melting and Freezing
15.2K
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
15.2K