Video Experimental Relacionado
Updated: Feb 9, 2026
02:31
Phase Transitions and Effect of Intermolecular Forces
23.3K
La ingeniería del cariotipo por fusión cromosómica conduce al aislamiento reproductivo en la levadura
Jingchuan Luo1,2, Xiaoji Sun1, Brendan P Cormack2
1Institute for Systems Genetics, NYU Langone Health, New York, NY, USA.
Nature
|August 3, 2018
Resumen
La levadura de brote tolera una reducción cromosómica significativa, con una cepa de dos cromosomas que muestra defectos mínimos. Las fusiones cromosómicas pueden conducir al aislamiento reproductivo, lo que demuestra la robustez del genoma.
Área de la Ciencia:
- La genética
- Biología molecular
- Biología evolutiva
Sus antecedentes:
- Las especies exhiben diversos números de cromosomas, incluso con tamaños de genoma similares, debido a eventos de la historia del genoma como fusiones y duplicaciones.
- El número de cromosomas humanos difiere de otros simios debido a un evento de fusión, lo que genera preguntas sobre la tolerancia a los cambios cromosómicos.
Objetivo del estudio:
- Investigar la tolerancia de las especies de levadura a los cambios significativos en el número de cromosomas.
- Explorar el impacto de la reducción cromosómica en el crecimiento de la levadura, la transcriptómica y el aislamiento reproductivo.
Principales métodos:
- Utilizó la edición del genoma CRISPR-Cas9 para fusionar cromosomas en Saccharomyces cerevisiae.
- Generó una serie de cepas de levadura con números cromosómicos progresivamente reducidos (dieciséis a dos).
- Se evaluaron los cambios transcriptómicos, los defectos de crecimiento y la viabilidad de las esporas en cruces entre cepas con diferentes conteos de cromosomas.
Principales resultados:
- Una cepa de levadura de dos cromosomas (aprox. 6 megabases cada una) mostraron modestas alteraciones transcriptómicas y un crecimiento normal.
- La viabilidad de las esporas disminuyó significativamente a medida que el número de cromosomas cayó por debajo de dieciséis, con menos del 10% de viabilidad en doce cromosomas.
- Los cruces homotípicos entre cepas con ocho, cuatro o dos cromosomas mostraron una excelente esporulación y viabilidad, lo que indica el aislamiento reproductivo después de ocho eventos de fusión.
Conclusiones:
- La levadura en ciernes demuestra una notable tolerancia a la reducción del número de cromosomas.
- Los eventos de fusión cromosómica son suficientes para establecer el aislamiento reproductivo entre las cepas de levadura.
- Este estudio proporciona un modelo para comprender la robustez del genoma y la flexibilidad evolutiva del número de cromosomas.
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