de Frutos C, López-Cardona A P, Fonseca Balvís N, Laguna-Barraza R, Rizos D, Gutierrez-Adán A, Bermejo-Álvarez P
Instituto Nacional de Investigación y Tecnología Agraria y AlimentariaAvenida Puerta de Hierro 12 local 10, 28040 Madrid, Spain.
Instituto Nacional de Investigación y Tecnología Agraria y AlimentariaAvenida Puerta de Hierro 12 local 10, 28040 Madrid, Spain
Reproduction. 2016 Jan;151(1):1-7. doi: 10.1530/REP-15-0375. Epub 2015 Oct 16.
Offspring telomere length (TL) has been correlated with paternal TL, but the mechanism for this parent of origin-specific inheritance remains unclear. The objective of this study has been to determine the role of spermatozoa TL in embryonic telomere lengthening by using two mouse models showing dimorphism in their spermatozoa TL: Mus musculus vs Mus spretus and old vs young Mus musculus. Mus spretus spermatozoa displayed a shorter TL than Mus musculus. Hybrid offspring exhibited lower TL compared with Mus musculus starting at the two-cell stage, before the onset of telomerase expression. To analyze the role of spermatozoa telomeres in early telomere lengthening, we compared the TL in oocytes, zygotes, two-cell embryos and blastocysts produced by parthenogenesis or by fertilization with Mus musculus or Mus spretus spermatozoa. TL was significantly higher in spermatozoa compared with oocytes, and it increased significantly from the oocyte to the zygote stage in those embryos fertilized with Mus musculus spermatozoa, but not in those fertilized with Mus spretus spermatozoa or produced by parthenogenesis. A further increase was noted from the zygote to the two-cell stage in fertilized Mus musculus embryos, whereas hybrid embryos maintained the oocyte TL. Spermatozoa TL shortened with age in Mus musculus and the offspring from young males showed a significantly higher TL compared with that fathered by old males. These significant differences were already noticeable at the two-cell stage. These results suggest that spermatozoa telomeres act as a guide for telomerase-independent telomere lengthening resulting in differences in TL that persist after birth.
子代端粒长度（TL）与父代TL相关，但这种源自特定亲本的遗传机制尚不清楚。本研究的目的是通过使用两种精子TL存在二态性的小鼠模型来确定精子TL在胚胎端粒延长中的作用：小家鼠与西班牙小鼠，以及老年小家鼠与幼年小家鼠。西班牙小鼠的精子TL比小家鼠短。从两细胞阶段开始，在端粒酶表达开始之前，杂种后代的TL就比小家鼠低。为了分析精子端粒在早期端粒延长中的作用，我们比较了孤雌生殖或用小家鼠或西班牙小鼠精子受精产生的卵母细胞、受精卵、两细胞胚胎和囊胚中的TL。精子中的TL显著高于卵母细胞，在用小家鼠精子受精的胚胎中，从卵母细胞到受精卵阶段TL显著增加，但在用西班牙小鼠精子受精或孤雌生殖产生的胚胎中则没有。在用小家鼠精子受精的胚胎中，从受精卵到两细胞阶段TL进一步增加，而杂种胚胎则维持卵母细胞的TL。小家鼠精子的TL随年龄增长而缩短，幼年雄性的后代与老年雄性的后代相比，TL显著更高。这些显著差异在两细胞阶段就已经很明显了。这些结果表明，精子端粒作为独立于端粒酶的端粒延长的指导，导致出生后持续存在的TL差异。
