A hVIPR transgene as a novel tool for the analysis of circadian function in the mouse suprachiasmatic nucleus.
A mouse bearing a novel transgene encoding the human VPAC2 receptor (hVIPR; Shen et al. (2000) PNAS, 97, 11575-11580) was used to investigate circadian function in the hypothalamic suprachiasmatic nuclei (SCN). Neurons expressing hVPAC2R, detected by a beta-galactosidase (beta-GAL) tag, have a distinct distribution within the SCN, closely matching that of neurophysin (NP) neurons and extending into the region of peptide histidine isoleucine (PHI) cells. In common with NP and PHI cells, neurons expressing hVPAC2R are circadian in nature, as revealed by synchronous rhythmic expression of mPERIOD (mPER) proteins. A population of SCN cells not expressing PHI, NP or hVPAC2R exhibited circadian PER expression antiphasic with the rest of the SCN. Nocturnal light exposure induced mPER1 in the ventral SCN and mPER2 widely across the nucleus. Induction of nuclear mPER2 in hVPAC2R cells confirmed their photic responsiveness. Having established their circadian properties, we tested the utility of SCN neurons expressing the hVIPR transgene as functionally and anatomically explicit markers for SCN tissue grafts. Prenatal SCN tissue from hVIPR transgenic pups survived transplantation into adult CD1 mice, and expressed beta-GAL, PER and PHI. Over a series of studies, hVIPR transgenic SCN grafts restored circadian activity rhythms to 17 of 72 arrhythmic SCN lesioned recipients (23.6%). By using heterozygous hVIPR transgenic grafts on a heterozygous Clock mutant background we confirmed that restored activity rhythms were conferred by the donor tissue. We conclude that the hVIPR transgene is a powerful and flexible tool for examination of circadian function in the mouse SCN.
King
V M
VM
Department of Anatomy, University of Cambridge, Cambridge CB2 3DY, UK.
Chahad-Ehlers
S
S
Shen
S
S
Harmar
A J
AJ
Maywood
E S
ES
Hastings
M H
MH
D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal; D016380:Brain Tissue Transplantation / Q000379:methods; D002452:Cell Count; D018797:Cell Cycle Proteins; D016009:Chi-Square Distribution; D002940:Circadian Rhythm / Q000235:genetics* / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008822:Mice, Transgenic / Q000378:metabolism; D009043:Motor Activity / Q000235:genetics / Q000502:physiology; D009481:Neurophysins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D010451:Peptide PHI / Q000378:metabolism; D056950:Period Circadian Proteins; D010775:Photic Stimulation; D018005:Receptors, Vasoactive Intestinal Peptide / Q000235:genetics* / Q000378:metabolism*; D051239:Receptors, Vasoactive Intestinal Peptide, Type II; D018709:Statistics, Nonparametric; D013493:Suprachiasmatic Nucleus / Q000166:cytology / Q000378:metabolism* / Q000637:transplantation; D013997:Time Factors; D014157:Transcription Factors; D001616:beta-Galactosidase / Q000378:metabolism
D018797:Cell Cycle Proteins; D009481:Neurophysins; D009687:Nuclear Proteins; C539022:PER1 protein, human; C421902:PER2 protein, human; D010451:Peptide PHI; C539023:Per1 protein, mouse; C513312:Per2 protein, mouse; D056950:Period Circadian Proteins; D018005:Receptors, Vasoactive Intestinal Peptide; D051239:Receptors, Vasoactive Intestinal Peptide, Type II; D014157:Transcription Factors; D001616:beta-Galactosidase