title: Decreasing period-length of the endogenous circadian rhythm of oxygen evolution in Acetabularia and its possible relation to aging.
abstract: Endogenous circadian rhythms observed under constant conditions normally show period length variations. However, a general trend is difficult to identify when cells or organisms are entrained with the usual 24-h-period light/dark cycles. Therefore, these variations in time have been considered as fluctuations. In order to gain more insight into this phenomenon, individual Acetabularia cells were exposed to light/dark cycles of 16 h (LD 8:8) and 33.6 h (LD 16.8:16.8), respectively, i.e., periods which lie distinctly outside the range of the normal circadian entrainment. Employing a high-resolution procedure for data analysis, decreasing period lengths could consistently be detected when cells were kept under constant conditions for several weeks. Possible causes of this decrease are discussed.
authors.affiliation: Max-Planck-Institut für Zellbiologie, Ladenburg, Germany.
authors.forename: L
authors.initials: L
authors.lastname: von Lindern
authors.forename: S
authors.initials: S
authors.lastname: Berger
mesh_terms: D000076:Acetabularia / Q000378:metabolism*; D002940:Circadian Rhythm; D003624:Darkness; D008027:Light; D010100:Oxygen / Q000378:metabolism*; D013997:Time Factors
chemical_list: D010100:Oxygen