Video Experimental Relacionado
Updated: Jul 10, 2026

07:54
Manipulation of Ploidy in Caenorhabditis elegans
Published on: March 15, 2018
La rotación de cromosomas sexuales inducida por el conflicto sexual
1Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, New Mexico 87501, USA. vandoorn@santafe.edu
Nature
|October 19, 2007
Resumen
Los genes que determinan el sexo pueden evolucionar rápidamente y moverse dentro de los genomas. La selección sexualmente antagonista en los genes autosómicos puede impulsar la propagación de nuevos genes determinantes del sexo, lo que explica la labilidad evolutiva.
Área de la Ciencia:
- Genética evolutiva de la genética evolutiva.
- La genómica es la genómica.
- Reproducción de los animales La reproducción de los animales es la reproducción de los animales.
Sus antecedentes:
- Los genes de determinación del sexo exhiben una alta fluidez evolutiva en todos los taxones animales.
- Las teorías existentes explican los cromosomas sexuales estables (por ejemplo, los mamíferos), pero no la labilidad en otros grupos.
- La dinámica evolutiva de la determinación genética del sexo sigue siendo en gran medida inexplicable en muchas especies.
Objetivo del estudio:
- Investigar teóricamente la labilidad evolutiva de la determinación genética del sexo.
- Para explicar el origen de los nuevos loci determinantes del sexo y el movimiento de los genes.
- Comprender el mantenimiento de múltiples factores determinantes del sexo en especies que carecen de cromosomas sexuales distintos.
Principales métodos:
- Modelado teórico de la evolución génica bajo la selección sexualmente antagónica.
- Simulación de la propagación de nuevos genes determinantes del sexo vinculados a los loci autosómicos.
Principales resultados:
- Un gen autosómico bajo selección sexualmente antagonista puede facilitar la propagación de un gen vinculado que determina el sexo.
- Este mecanismo explica el origen de nuevos loci determinantes del sexo.
- También explica la transposición de genes ancestrales que determinan el sexo a los autosomas.
Conclusiones:
- La selección sexualmente antagónica proporciona una poderosa fuerza evolutiva que impulsa la dinámica de la determinación del sexo.
- El modelo aclara los orígenes de la labilidad genética de determinación del sexo y el mantenimiento de múltiples factores sexuales.
- Este marco teórico ofrece información sobre las especies que carecen de cromosomas sexuales morfológicamente distintos.
Videos de Conceptos Relacionados
Crossing Over
Crossing over is the exchange of genetic information between homologous chromosomes during prophase I of meiosis I. Genetic recombination gives rise to allelic diversity in the newly formed daughter cells. In humans, crossing over produces genetically distinct haploid egg and sperm cells that undergo fertilization to produce unique offspring. Before cell division starts, the germ cell’s chromosome(s) undergo duplication in the S phase of the cell cycle. As the cells enter prophase I, duplicated...
Crossing Over
Unlike mitosis, meiosis aims for genetic diversity in its creation of haploid gametes. Dividing germ cells first begin this process in prophase I, where each chromosome—replicated in S phase—is now composed of two sister chromatids (identical copies) joined centrally.
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...
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...
Nondisjunction
During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.
Nondisjunction
Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate correctly and move to the opposite poles of the cells. This produces daughter cells with abnormal chromosome numbers. Nondisjunction is common during anaphase I or anaphase II of meiosis. Mutations in synaptonemal complex proteins that attach homologous chromosomes increase the chances of nondisjunction in anaphase I of meiosis I. In contrast, mutations in topoisomerases and condensins that hold sister...
Nondisjunction
During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.

