Video Experimental Relacionado
Updated: Jul 21, 2026
14:50
Understanding Early Organogenesis Using a Simplified In Situ Hybridization Protocol in Xenopus
Published on: January 12, 2015
El mecanismo de la dominación nucleolar en los híbridos de Xenopus
Cell
|August 1, 1984
Resumen
Los genes ribosómicos de Xenopus laevis dominan en los embriones híbridos debido a más elementos potenciadores y una mejor función promotora en comparación con Xenopus borealis. Esto explica el dominio nucleolar en estas especies.
Área de la Ciencia:
- Biología del desarrollo Biología del desarrollo.
- Genética La genética.
Sus antecedentes:
- La dominación nucleolar es un fenómeno en el que solo un conjunto de genes ribosómicos se expresa en los híbridos.
- Comprender las bases genéticas y moleculares de la dominación nucleolar es crucial para los estudios del desarrollo.
Objetivo del estudio:
- Investigar los mecanismos subyacentes a la dominación nucleolar entre Xenopus laevis y Xenopus borealis.
- Identificar los factores responsables de la expresión preferencial de los genes ribosómicos de X. laevis en embriones híbridos.
Principales métodos:
- Microinyección de genes ribosómicos clonados de X. laevis y X. borealis en ovocitos y embriones de ambas especies.
- Análisis de la expresión génica y la actividad promotora en sistemas híbridos.
Principales resultados:
- Los genes ribosómicos de X. laevis muestran una predominancia en los embriones híbridos.
- El espaciador de X. laevis contiene más elementos potenciadores para el promotor del gen ribosomal que el espaciador de X. borealis.
- El promotor de X. laevis funciona eficientemente con la maquinaria de transcripción de ambas especies, mientras que el promotor de X. borealis interactúa mal con la maquinaria de transcripción de X. laevis.
Conclusiones:
- El dominio de los genes ribosómicos de X. laevis se atribuye principalmente a un mayor número de elementos potenciadores en su región espaciadora.
- Las diferentes interacciones promotor-maquinaria también contribuyen al dominio nucleolar, favoreciendo a X. laevis.
Más Videos Relacionados
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.
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
03:17Inheritance of Chromatin Structures
Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying DNA...
01:43Incomplete Dominance
Gregor Mendel's work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid cell has two variants called alleles inherited from each parent. He suggested that amongst these two alleles, one allele is dominant in character and the other recessive. The combination of alleles determines the phenotype of a gene in an organism.
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...