Video Experimental Relacionado
Updated: May 10, 2026

14:08
Blastomere Explants to Test for Cell Fate Commitment During Embryonic Development
Published on: January 26, 2013
Un gen que contiene una caja homeogénica expresado durante la oogénesis en Xenopus
Cell
|November 1, 1984
Resumen
Los investigadores aislaron un nuevo gen de Xenopus con un dominio homeo, similar a los genes de Drosophila. Este gen está altamente transcrito en los ovocitos, lo que sugiere un papel en la determinación temprana del tipo de célula embrionaria.
Área de la Ciencia:
- Biología del desarrollo Biología del desarrollo.
- Biología Molecular Biología Molecular
- Genética La genética.
Sus antecedentes:
- Los genes homeobox son cruciales para el desarrollo embrionario en varias especies.
- El aislamiento previo de un gen homeobox de Xenopus destacó las vías de desarrollo conservadas.
- Los genes homeóticos de Drosophila, como Antennapedia, sirven como modelos clave para comprender la función de los genes.
Objetivo del estudio:
- Informar sobre el aislamiento y la caracterización de un segundo gen que contiene homeobox en Xenopus.
- Para investigar la conservación evolutiva de la secuencia del homeodomain.
- Para explorar el papel potencial de este gen en la embriogénesis temprana de Xenopus.
Principales métodos:
- Aislamiento y secuenciación de genes de Xenopus laevis.
- Análisis de homología del homeodomain con genes conocidos (Drosophila Antennapedia, gen de rana previamente aislado).
- Análisis de los niveles de transcripción génica en los ovocitos de Xenopus.
Principales resultados:
- Aislamiento de un nuevo gen de Xenopus que posee un dominio homeo.
- Conservación de alta secuencia (59/60 aminoácidos) del homeodominio con Drosophila Antennapedia.
- Conservación significativa (54/60 aminoácidos) con un gen homeobox de rana previamente identificado.
- Transcripción abundante del gen en óvulos grandes de Xenopus.
- Identificación de un único carboxitermino con una cola de ácido poliglutámico.
Conclusiones:
- El gen de Xenopus recién aislado representa un gen conservado que contiene homeobox potencialmente involucrado en el desarrollo.
- Su abundante transcripción en los ovocitos sugiere un papel en la expresión génica materna.
- El producto proteico puede desempeñar un papel crítico en la determinación temprana de los tipos de células embrionarias en Xenopus.
Videos de Conceptos Relacionados
Oogenesis
In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...
X and Y Chromosomes
Among mammals, the gender of an organism is determined by the sex chromosomes. Humans have two sex chromosomes, X and Y. Every human diploid cell has 22 pairs of autosomes and one pair of sex chromosomes. A human female has two X chromosomes, while a male has one X chromosome and one Y chromosome.
The germline cells such as egg and sperm cells carry only half the number of chromosomes, i.e., 22 autosomes and one sex chromosome. All eggs have an X chromosome, while sperm cells can carry an X or...
The germline cells such as egg and sperm cells carry only half the number of chromosomes, i.e., 22 autosomes and one sex chromosome. All eggs have an X chromosome, while sperm cells can carry an X or...
The 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...
Dosage 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...
Heterochromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Oogenesis
Oogenesis, the process of developing egg cells (female gametes), occurs within the ovaries and is fundamental to female fertility. This sequence begins during fetal development when diploid oogonia in the developing ovaries undergo mitotic divisions to produce primary oocytes. By birth, these primary oocytes enter prophase I of meiosis but become arrested in this stage, remaining suspended until puberty.
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is known...
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is known...

