TY - JOUR
T1 - Decrease in cytosine methylation at CpG island shores and increase in DNA fragmentation during zebrafish aging
AU - Shimoda, Nobuyoshi
AU - Izawa, Toshiaki
AU - Yoshizawa, Akio
AU - Yokoi, Hayoto
AU - Kikuchi, Yutaka
AU - Hashimoto, Naohiro
PY - 2014/2
Y1 - 2014/2
N2 - Age-related changes in DNA methylation have been demonstrated in mammals, but it remains unclear as to the generality of this phenomenon in vertebrates, which is a criterion for the fundamental cause of senescence. Here we showed that the zebrafish genome gradually and clearly lost methylcytosine in somatic cells, but not in male germ cells during aging, and that age-dependent hypomethylation preferentially occurred at a particular domain called the CpG island shore,which is associated with vertebrates' genes and has been shown to be hypomethylated in humans with age. We also found that two CpG island shores hypomethylated in zebrafish oocytes were de novo methylated in fertilized eggs, which suggests that the zebrafish epigenome is reset upon fertilization, enabling new generations to restart with a heavily methylated genome. Furthermore, we observed an increase in cleavage of the zebrafish genome to an oligonucleosome length in somatic cells from the age of 12 months, which is suggestive of an elevated rate of apoptosis in the senescent stage.
AB - Age-related changes in DNA methylation have been demonstrated in mammals, but it remains unclear as to the generality of this phenomenon in vertebrates, which is a criterion for the fundamental cause of senescence. Here we showed that the zebrafish genome gradually and clearly lost methylcytosine in somatic cells, but not in male germ cells during aging, and that age-dependent hypomethylation preferentially occurred at a particular domain called the CpG island shore,which is associated with vertebrates' genes and has been shown to be hypomethylated in humans with age. We also found that two CpG island shores hypomethylated in zebrafish oocytes were de novo methylated in fertilized eggs, which suggests that the zebrafish epigenome is reset upon fertilization, enabling new generations to restart with a heavily methylated genome. Furthermore, we observed an increase in cleavage of the zebrafish genome to an oligonucleosome length in somatic cells from the age of 12 months, which is suggestive of an elevated rate of apoptosis in the senescent stage.
KW - Aging
KW - CpG island shore
KW - DNA methylation
KW - Zebrafish
UR - http://www.scopus.com/inward/record.url?scp=84899110910&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84899110910&partnerID=8YFLogxK
U2 - 10.1007/s11357-013-9548-5
DO - 10.1007/s11357-013-9548-5
M3 - Article
C2 - 23736955
AN - SCOPUS:84899110910
VL - 36
SP - 103
EP - 115
JO - GeroScience
JF - GeroScience
SN - 2509-2715
IS - 1
ER -