Video Experimental Relacionado
Updated: Jul 24, 2026

06:38
Determination of Reproductive Competence by Confirming Pubertal Onset and Performing a Fertility Assay in Mice and Rats
Published on: October 13, 2018
Diferenciación sexual masculina en ratones que carecen del antígeno H-Y
Nature
|December 6, 1984
Resumen
El antígeno H-Y, que anteriormente se pensaba que determinaba el sexo masculino en los mamíferos, está ausente en algunos ratones machos. Este hallazgo desafía el antígeno H-Y.
Área de la Ciencia:
- Genética de mamíferos genética de mamíferos
- Biología del desarrollo Biología del desarrollo.
- Inmunología Inmunología.
Sus antecedentes:
- El fenotipo sexual de los mamíferos está determinado por la diferenciación de las gónadas fetales en testículos u ovarios.
- El cromosoma Y normalmente dirige el desarrollo del testículo, mientras que su ausencia conduce a la diferenciación de los ovarios.
- Se ha debatido el factor Y-dependiente exacto que induce el desarrollo del testículo, siendo el antígeno H-Y una hipótesis prominente.
Objetivo del estudio:
- Para investigar el papel del antígeno H-Y en la determinación del sexo de los mamíferos.
- Para determinar si el antígeno H-Y es esencial para la diferenciación de los testículos.
Principales métodos:
- Análisis de la presencia del antígeno H-Y en ratones con fenotipos masculinos pero con diferentes constituciones de cromosomas sexuales.
- Evaluación fenotípica de la diferenciación de las gónadas en modelos experimentales de ratón.
Principales resultados:
- Se encontró que el antígeno H-Y estaba ausente en ciertos ratones con un fenótipo indiscutiblemente masculino y testículos desarrollados.
- Esto indica que el antígeno H-Y no es universalmente requerido para la determinación del testículo.
Conclusiones:
- Es poco probable que el antígeno H-Y sea la única o principal sustancia dependiente de Y responsable de la determinación del testículo.
- Se necesita más investigación para identificar los verdaderos mecanismos moleculares subyacentes a la determinación del sexo de los mamíferos.
Videos de Conceptos Relacionados
Sex-linked Disorders
Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked.
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 Y Chromosome Determines Maleness
The Y chromosome is a sex chromosome found in several vertebrates and mammals, including humans. In addition to 22 pairs of autosomes, the human males have one X chromosome and one Y chromosome. In these organisms, the presence or absence of the Y chromosome determines the development of male traits.
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size. Today,...
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size. Today,...
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...
Development of the Sexual Organs in the Embryo and Fetus
Development of the reproductive organs in an embryo starts from a bipotential state. This means the early embryo can develop either male or female reproductive organs. The formation of these organs begins with the growth of gonadal ridges that arise from the intermediate mesoderm during the fifth week of development.
Near the gonadal ridges, two duct systems are present: the mesonephric ducts (Wolffian ducts) and paramesonephric ducts (Müllerian ducts). These ducts form the basis for the male...
Near the gonadal ridges, two duct systems are present: the mesonephric ducts (Wolffian ducts) and paramesonephric ducts (Müllerian ducts). These ducts form the basis for the male...

