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Guinea pig cerebellar histones but not DNA turns over in the first year of life
Author(s) -
Varamini Behzad,
Tschanz Carolyn L,
Brenna J Thomas
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a321-d
Subject(s) - cerebellum , histone , biology , guinea pig , dna , gestation , fetus , dna methylation , medicine , endocrinology , physiology , pregnancy , biochemistry , genetics , gene , gene expression
Background. The DNA of cerebellar neurons of humans does not turnover after the perinatal period, and therefore cerebellar DNA represents a sampling of the isotopic environment prevailing during CNS development. With isotopic labeling, we tested whether cerebellar DNA, histones, and the bulk turns over in the first year of life in guinea pigs. Guinea pigs are born after 68 da gestation with their CNS at an advanced development stage. Methods. Pregnant guinea pigs were maintained on a isotopically homogeneous, balanced diet throughout gestation. For 20 da during fetal brain development, feed was supplemented with algal biomass labeled with 13 C and 15 N. Pups were weaned within one week of birth to the non‐labeled diet. Cerebellum, cerebellar DNA, and histones were prepared and δ 13 C and δ 15 N determined at several times from 2 da to 1 year postpartum. Results. A plot of δ 13 C and δ 15 N for cerebellar DNA over the first year of life yielded a slope that was not significantly different from zero, indicating no measurable turnover of DNA. Bulk cerebellum turned over with a half‐life of about 30 da and was back to baseline by six months. Similar results were obtained for cerebellar histones. Conclusions. These data demonstrate in vivo that post‐mitotic neuron histones turn over, and that the guinea pig cerebellar neuron DNA, like in humans, is a long term repository of isotopic information from the perinatal period. Funding: NIH GM071534 and DK07158.