PNAS：父系祖父生育时的年龄影响孙辈端粒长度

一项刊登在<em>PNAS</em>上的研究提出，男性进行生育的年龄可能决定了他的孙辈的端粒——在染色体末端的被认为用于防止衰老和疾病的分子帽——的长度。与鞋带的塑料末端类似，端粒保护染色体末端免于分解。

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在大多数细胞中，端粒随着衰老而缩短。但是在精子中，端粒随着衰老而加长。相应地，在较大年龄进行生育的男性得到的孩子的端粒比在较小年龄进行生育的男性的孩子的端粒更长。Dan Eisenberg及其同事使用来自对菲律宾人的多代人研究的信息调查了男性进行生育的年龄是否影响几代人的端粒长度。这组作者用1799位年轻的成年人及其母亲的血样测量了端粒长度，然后确定了这些人的父亲和祖父的年龄。

这组作者发现，个体的端粒长度不仅随着他们出生时父亲的年龄而增加，而且随着他们的父亲出生时祖父的年龄而进一步增加。父亲推迟生育1年带来的端粒长度的增加大致相当于在中年成年人身上观察到的每年的端粒缩短量。这组作者说，这些发现提示，推迟父亲的生育可以导致后代端粒长度的累积的、多代人的增加，这可能促进长寿。 
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<img src="http://www.bioon.com/biology/UploadFiles/201206/2012061210204642.jpg" alt="" width="113" height="149" border="0" />

<a title="" href="http://dx.doi.org/doi:10.1073/pnas.1202092109" target="_blank">doi:10.1073/pnas.1202092109</a>
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<br/><strong>Delayed paternal age of reproduction in humans is associated with longer telomeres across two generations of descendants</strong><br/>


Dan T. A. Eisenberga,b,c,1, M. Geoffrey Hayesa,d,e,2, and Christopher W. Kuzawaa,b,2

Telomeres are repeating DNA sequences at the ends of chromosomes that protect and buffer genes from nucleotide loss as cells divide. Telomere length (TL) shortens with age in most proliferating tissues, limiting cell division and thereby contributing to senescence. However, TL increases with age in sperm, and, correspondingly, offspring of older fathers inherit longer telomeres. Using data and samples from a longitudinal study from the Philippines, we first replicate the finding that paternal age at birth is associated with longer TL in offspring (n = 2,023, P = 1.84 × 10−6). We then show that this association of paternal age with offspring TL is cumulative across multiple generations: in this sample, grandchildren of older paternal grandfathers at the birth of fathers have longer telomeres (n = 234, P = 0.038), independent of, and additive to, the association of their father’s age at birth with TL. The lengthening of telomeres predicted by each year that the father’s or grandfather’s reproduction are delayed is equal to the yearly shortening of TL seen in middle-age to elderly women in this sample, pointing to potentially important impacts on health and the pace of senescent decline in tissues and systems that are cell-replication dependent. This finding suggests a mechanism by which humans could extend late-life function as average age at reproduction is delayed within a lineage.

<br/>来源：EurekAlert

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