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La longitud de los telómeros y el posible vínculo con el cromosoma X
Tim S Nawrot1, Jan A Staessen, Jeffrey P Gardner
1Study Coordinating Centre, Laboratory of Hypertension, Department of Molecular and Cardiovascular Research, University of Leuven, Campus Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium.
Lancet (London, England)
|February 21, 2004
Resumen
La longitud de los telómeros, un marcador del envejecimiento celular, parece ser heredada de una manera vinculada a X. Esto sugiere que el proceso de envejecimiento en sí mismo puede ser un rasgo vinculado a X.
Área de la Ciencia:
- Genética La genética.
- Biología Humana Biología Humana.
- Investigación sobre el envejecimiento Investigación sobre el envejecimiento.
Sus antecedentes:
- La longitud de los telómeros refleja la historia de replicación celular y está relacionada con los marcadores clínicos del envejecimiento.
- Estudios previos de gemelos sugieren que la longitud de los telómeros es familiar, pero su patrón de herencia sigue sin estar claro.
Objetivo del estudio:
- Investigar el modo de herencia de la longitud de los telómeros en humanos.
Principales métodos:
- La longitud del fragmento de restricción terminal (TRF) se midió en el ADN de los glóbulos blancos.
- Los datos se recopilaron de una cohorte basada en la familia (Estudio flamenco sobre el medio ambiente, los genes y los resultados de salud).
Principales resultados:
- No se encontró una correlación significativa en la longitud de TRF entre cónyuges o entre padres e hijos.
- Se observaron fuertes correlaciones en la longitud de TRF entre padres e hijas, madres e hijos y entre hermanos.
Conclusiones:
- La herencia ligada a X es la explicación más probable para las correlaciones observadas de la longitud de los telómeros.
- Estos hallazgos sugieren que el envejecimiento puede ser un rasgo vinculado a X, a la espera de una confirmación adicional.
Videos de Conceptos Relacionados
01:18Dihybrid Crosses
Overview
01:19X-linked Traits
In most mammalian species, females have two X sex chromosomes and males have an X and Y. As a result, mutations on the X chromosome in females may be masked by the presence of a normal allele on the second X. In contrast, a mutation on the X chromosome in males more often causes observable biological defects, as there is no normal X to compensate. Trait variations arising from mutations on the X chromosome are called “X-linked”.
02:27Trihybrid Crosses
Trihybrid Crosses
Some of Mendel’s crosses examined three pairs of contrasting characteristics. Such a cross is called a trihybrid cross. A trihybrid cross is a combination of three individual monohybrid crosses. For example, plant height (tall vs. short), seed shape (round vs. wrinkled), and seed color (yellow vs. green).
The F1 generation plants of a trihybrid cross are heterozygous for all three traits and produce eight gametes. Upon self-fertilization, these gametes have an equal chance to...
Some of Mendel’s crosses examined three pairs of contrasting characteristics. Such a cross is called a trihybrid cross. A trihybrid cross is a combination of three individual monohybrid crosses. For example, plant height (tall vs. short), seed shape (round vs. wrinkled), and seed color (yellow vs. green).
The F1 generation plants of a trihybrid cross are heterozygous for all three traits and produce eight gametes. Upon self-fertilization, these gametes have an equal chance to...
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.
02:32X 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...
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...