Circadian genes in a blind subterranean mammal II: conservation and uniqueness of the three Period homologs in the blind subterranean mole rat, Spalax ehrenbergi superspecies.
We demonstrated that a subterranean, visually blind mammal has a functional set of three Per genes that are important components of the circadian clockwork in mammals. The mole rat superspecies Spalax ehrenbergi is a blind subterranean animal that lives its entire life underground in darkness. It has degenerated eyes, but the retina and highly hypertrophic harderian gland are involved in photoperiodic perception. All three Per genes oscillate with a periodicity of 24 h in the suprachiasmatic nuclei, eye, and harderian gland and are expressed in peripheral organs. This oscillation is maintained under constant conditions. The light inducibility of sPer1 and sPer2, which are similar in structure to those of other mammals, indicates the role of these genes in clock resetting. However, sPer3 is unique in mammals and has two truncated isoforms, and its expressional analysis leaves its function unresolved. Per's expression analysis in the harderian gland suggests an important participation of this organ in the stabilization and resetting mechanism of the central pacemaker in the suprachiasmatic nuclei and in unique adaptation to life underground.
Avivi
Aaron
A
Laboratory of Animal Molecular Evolution, Institute of Evolution, University of Haifa, Mount Carmel, Haifa 31905, Israel. aaron@esti.haifa.ac.il
Oster
Henrik
H
Joel
Alma
A
Beiles
Avigdor
A
Albrecht
Urs
U
Nevo
Eviatar
E
D000818:Animals; D018797:Cell Cycle Proteins; D002940:Circadian Rhythm / Q000235:genetics*; D003001:Cloning, Molecular; D019143:Evolution, Molecular; D017403:In Situ Hybridization; D019577:Mole Rats / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D056950:Period Circadian Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity; D013493:Suprachiasmatic Nucleus / Q000378:metabolism; D014157:Transcription Factors
D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; C513311:Per2 protein, rat; C512646:Per3 protein, rat; D056950:Period Circadian Proteins; D014157:Transcription Factors