Video Experimental Relacionado
Updated: Jul 20, 2026
10:02
Ex Vivo Culture of Chick Cerebellar Slices and Spatially Targeted Electroporation of Granule Cell Precursors
Published on: December 14, 2015
Evolución eucariota: origen temprano de los intrones canónicos
Alastair G B Simpson1, Erin K MacQuarrie, Andrew J Roger
1Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada. simpson@hades.biochem.da.ca
Nature
|September 20, 2002
Resumen
Los intrones spliceosómicos canónicos probablemente se originaron muy temprano en la evolución eucariota, no tan tarde como se pensaba anteriormente. El descubrimiento de intrones eucariotas normales en Carpediemonas membranifera desafía las suposiciones anteriores sobre la evolución de los intrones.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Biología evolutiva Biología evolutiva.
- La genómica es la genómica.
Sus antecedentes:
- Los intrones espliceosómicos son características clave de los genomas eucariotas.
- Anteriormente se creía que los intrones se habían originado a finales de la evolución eucariota.
- El descubrimiento de un solo intrón aberrante en Giardia provocó una reevaluación.
Objetivo del estudio:
- Para investigar los orígenes evolutivos de las intrones espliceosomales.
- Para determinar si existen intrones canónicos en eucariotas con divergencia temprana.
Principales métodos:
- Análisis de intrones en el genoma de Carpediemonas membranifera.
- Comparación de secuencias de límites de intrones con sitios conocidos de empalme de eucariotas.
Principales resultados:
- Intrones identificados con secuencias de frontera eucarióticas normales en Carpediemonas membranifera.
- Estos hallazgos sugieren la presencia de intrones canónicos en eucariotas con divergencia temprana.
Conclusiones:
- Los intrones spliceosómicos canónicos probablemente surgieron muy temprano en la evolución eucariota.
- La presencia de intrones normales en Carpediemonas membranifera refuta la hipótesis de origen tardío.
Videos de Conceptos Relacionados
02:55The 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,...
01:24Eukaryotic Evolution
The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the nucleus-first hypothesis, the ancestral prokaryote first evolved a membrane to enclose DNA and form the nucleus. Conversely, the mitochondria-first hypothesis suggests that the nucleus was formed after endosymbiosis of mitochondria.
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
01:10Zygotic Development And Stem Cell Formation
The development of all multicellular organisms starts with the fusion of haploid cells called sperm and egg to form a diploid zygote. A zygote is a totipotent cell that can develop into a complete organism. The zygote undergoes cell division or cleavage to form an 8-cell mass. Until this stage, the cells are spherical, loosely attached, and remain totipotent. Totipotent cells are capable of developing both the embryonic and the extraembryonic tissues. However, as they continue to divide, they...
01:14Introduction to Nuclear Reprogramming
Nuclear reprogramming is the process of switching gene expression of one cell type to that of another cell type, usually from a differentiated cell state to an undifferentiated cell state. Differentiation occurs during processes such as development and morphogenesis, tissue regeneration, and malignancy. Cells can also be artificially induced to reprogram their gene expression by techniques such as nuclear transfer, induced pluripotency, and cell fusion. Such techniques have many applications in...
01:24Methods of Nuclear Reprogramming
Nuclear reprogramming is a process of transforming one cell type into an unrelated cell type by epigenetic changes that alter the cell’s original gene expression pattern. Such epigenetic changes force cells to express a different set of genes, which play a significant role in inducing transformation into other cell types. Nuclear reprogramming offers applications in reproductive cloning for livestock propagation and regenerative medicine — developing patient-specific cells for injury repair.
00:57Cellular Differentiation
How does a complex organism such as a human develop from a single cell? It all starts from a single fertilized egg which gives rise to a vast array of cell types, such as nerve cells, muscle cells, and epithelial cells that characterize the adult? Throughout development and adulthood, cellular differentiation leads cells to assume their final morphology and physiology. Differentiation is the process by which unspecialized cells become specialized to carry out distinct functions.
A zygote is a...
A zygote is a...