Video Experimental Relacionado
Updated: Jun 26, 2026
11:00
Tissue Determination Using the Animal Cap Transplant (ACT) Assay in Xenopus laevis
Published on: May 17, 2010
Xenopus chordin: un nuevo factor dorsalizante activado por genes homeobox específicos del organizador
Y Sasai1, B Lu, H Steinbeisser
1Molecular Biology Institute, University of California, Los Angeles 90024-1737.
Cell
|December 2, 1994
Resumen
Los investigadores identificaron el gen del cordón en Xenopus, un factor clave en el desarrollo embrionario. El cordón actúa como un potente factor dorsalizante, esencial para regular la formación de la cabeza, el tronco y la cola.
Área de la Ciencia:
- Biología del desarrollo Biología del desarrollo.
- Biología Molecular Biología Molecular
- Xenopus laevis Investigación Investigación de las especies.
Sus antecedentes:
- Los genes homeobox específicos de los organizadores como goosecoid y Xnot2 juegan un papel crucial en el patrón embrionario.
- Comprender los mecanismos moleculares que regulan el desarrollo axial es fundamental para la biología del desarrollo.
Objetivo del estudio:
- Para aislar y caracterizar nuevos genes involucrados en la formación del eje embrionario en Xenopus.
- Investigar el papel del gen de cordón recién identificado en la regulación de la dorsalización y el desarrollo axial.
Principales métodos:
- Se empleó el cribado diferencial para identificar genes activados por genes homeobox específicos del organizador.
- Los patrones de expresión génica de cordón fueron analizados durante el desarrollo embrionario.
- Se realizó una microinyección de ARNm de cordón para evaluar sus efectos en el desarrollo axial en embriones ventralizados.
Principales resultados:
- Se aisló un nuevo gen, el chordin, que codifica una proteína con una secuencia de señal y cuatro dominios ricos en Cys.
- La expresión del cordón se inicia en el organizador de Spemann después de la goosecoid y requiere de novo la síntesis de proteínas para la inducción de activina.
- La microinyección de ARNm de cordón indujo con éxito los ejes gemelos y salvó el desarrollo axial en embriones de Xenopus ventralizados.
Conclusiones:
- El cordón es un potente factor dorsalizante crucial para regular las interacciones célula-célula en los centros organizadores embrionarios.
- La expresión temporal y espacial del cordón sugiere su papel vital en el desarrollo de la cabeza, el tronco y la cola.
- La capacidad de Chordin para rescatar embriones ventralizados destaca su importancia en el establecimiento del eje primario del cuerpo.
Videos de Conceptos Relacionados
01:58X-Inactivation
The human X chromosome contains over ten times the number of genes as in the Y chromosome. Since males have only one X chromosome, and females have two, one might expect females to produce twice as many of the proteins, with undesirable results.
02:33Combinatorial Gene Control
Combinatorial gene control is the synergistic action of several transcriptional factors to regulate the expression of a single gene. The absence of one or more of these factors may lead to a significant difference in the level of gene expression or repression.
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...
02:23Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
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...
02:50Dosage Compensation
In animals, gender is determined by the number and type of sex chromosome. For example, human females have two X chromosomes, and males have one X and one Y chromosome, whereas C.elegans with one X chromosome is a male, and the one with two X chromosomes is a hermaphrodite.
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...
02:32Exon Recombination
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Exon shuffling follows “splice frame rules.” Each exon has three reading...