title: Glucocorticoid receptor binding in twin pairs is affected by shared environment but not by shared genes.
abstract: We set out to determine whether glucocorticoid receptor activity is affected mainly by genetic or environmental factors. The affinity and capacity of the glucocorticoid receptor was measured using dexamethasone binding in whole leukocytes from 53 monozygotic and 48 dizygotic twin pairs. Receptor binding characteristics assayed from twin pairs on the same day were highly correlated within twin pairs irrespective of zygosity. Apparent Kd was negatively correlated with environmental temperature (R(2)=0.13, P<0.0001) but this did not confound the intra-pair correlation, suggesting a strong familial component independent of zygosity. Receptor binding parameters were not more closely correlated in monozygotic twins than dizygotic twin pairs indicating that there is no major genetic contribution to receptor binding and that environmental influences predominate. The close similarity in binding between twin pairs in adulthood raises the possibility that familial, non-genetic, factors such as shared early life environment may programme the glucocorticoid receptor.
authors: Endocrinology Unit, Molecular Medicine Centre, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK. gblackhurst@ed.ac.uk
authors: Guthrie
authors: G
authors: Blackhurst
authors: Kenneth P
authors: KP
authors: McElroy
authors: Christopher J
authors: CJ
authors: Kenyon
authors: Robert
authors: R
authors: Fraser
authors: Lorna
authors: L
authors: Swan
authors: Niall
authors: N
authors: Anderson
authors: Stewart
authors: S
authors: Hillis
authors: John M C
authors: JM
authors: Connell
mesh_terms: D004777:Environment; D006801:Humans; D007700:Kinetics; D011485:Protein Binding; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D012621:Seasons; D013696:Temperature; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic
chemical_list: D011965:Receptors, Glucocorticoid