Telomere length is reset during early mammalian embryogenesis.
The enzyme telomerase is active in germ cells and early embryonic development and is crucial for the maintenance of telomere length. Whereas the different length of telomeres in germ cells and somatic cells is well documented, information on telomere length regulation during embryogenesis is lacking. In this study, we demonstrate a telomere elongation program at the transition from morula to blastocyst in mice and cattle that establishes a specific telomere length set point during embryogenesis. We show that this process restores telomeres in cloned embryos derived from fibroblasts, regardless of the telomere length of donor nuclei, and that telomere elongation at this stage of embryogenesis is telomerase-dependent because it is abrogated in telomerase-deficient mice. These data demonstrate that early mammalian embryos have a telomerase-dependent genetic program that elongates telomeres to a defined length, possibly required to ensure sufficient telomere reserves for species integrity.
Schaetzlein
Sonja
S
Department of Gastroenterology, Hepatology, and Endocrinology, and Institute for Animal Science, Hannover Medical School, 30625 Hannover, Germany.
Lucas-Hahn
Andrea
A
Lemme
Erika
E
Kues
Wilfried A
WA
Dorsch
Martina
M
Manns
Michael P
MP
Niemann
Heiner
H
Rudolph
K Lenhard
KL
D000818:Animals; D001755:Blastocyst / Q000378:metabolism; D002417:Cattle; D005314:Embryonic and Fetal Development / Q000235:genetics*; D017353:Gene Deletion; D017404:In Situ Hybridization, Fluorescence; D008322:Mammals / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D009028:Morula / Q000378:metabolism; D012313:RNA / Q000235:genetics; D019098:Telomerase / Q000172:deficiency / Q000235:genetics; D016615:Telomere / Q000737:chemistry* / Q000235:genetics*; D013997:Time Factors
C422952:telomerase RNA; D012313:RNA; D019098:Telomerase