Temperature entrainment is altered in per1. A and B, The transgenic wild-type strain Hsp70A-RbcS2pro:Ble-cRluc:Gs2-RbcS2-3′-UTR, designated WT (Ble-cRluc:Gs2) (Kiaulehn et al., 2007), expressing the chimeric crluc reporter gene under the control of the hsp70A-rbcS2 tandem promoter and the gs2 UG-repeat region within the rbcS2 3′-UTR, was grown in a 12/12-h temperature cycle (ThighTlow; A) and then released under constant temperature and dim light (B). cRLUC activities (n = 3) were measured at the indicated time points according to Kiaulehn et al. (2007). C and E, The transgenic per1 strain crluc 13, which expresses the chimeric Hsp70A-RbcS2pro:Ble-cRluc:Gs2-RbcS2-3′-UTR construct, designated per1 (Ble-cRluc:Gs2), was grown either under a light/dark cycle (C) or in a temperature cycle (ThighTlow; E). cRLUC activities (n = 3) were measured at the indicated time points according to A. D and F, The transgenic line per1 (Ble-cRluc:Gs2) was released under conditions of constant temperature and dim light either after LD entrainment (D) or after treatment with a temperature cycle (F). cRLUC activities (n = 3) were measured at the indicated time points according to A.