| Grant number: | 06/03381-1 |
| Support type: | Research Projects - Thematic Grants |
| Duration: | August 01, 2007 - July 31, 2012 |
| Field of knowledge: | Biological Sciences - Physiology - Compared Physiology |
| Principal researcher: | Ana Maria de Lauro Castrucci |
| Grantee: | Ana Maria de Lauro Castrucci |
| Home Institution: | Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil |
| Principal researchers: | Maria Aparecida Visconti |
| Assoc. researchers: | Mauro Cesar Isoldi |
| Associated scholarship(s): | 11/04048-2 - Modulatory role and signaling pathways of cortisol on the temporal expression of clock genes in ZEM-2S cell line,
BP.MS 11/02475-0 - Clock gene modulation by glutamate ionotropic receptors, BP.MS 09/05227-8 - Role of adrenal and ovarian steroids on the entrainment mechanism of the biological clock, BP.PD + associated scholarships - associated scholarships |
Abstract
Melanopsin can be expressed, as well as other opsins, in skin pigment cells, to mediate photoresponses. Having in mind that cultured cells may constitute peripheral clocks and respond to visible light, we will analyse: 1. the mechanisms to adjust biological clocks in single cells of teleosts, amphibians and mammals; 2. their regulation by varying photoperiod regimes and hormones; We will investigate: 1. whether ZEM-2S embryonic cell line of Danio rerio, melanophores of Xenopus laevis, and B-16 F10 murine melanoma cells are able to cycle genes such as Per1, independently of light:dark cycle; 2. whether opsin expression is rhythmic, dependent on the integrity of the cellular clock and independent of the light:dark cycle; 3. whether opsin and clock gene expressions may be modified by hormones. These hypotheses will be tested by the quantification of luciferin bioluminescence originated from the activation of luciferase located in Per1 promoter, of mRNA (and of proteins whenever possible) of opsinsand clock genes, under light:dark cycles, or constant darkness, in the presence of increasing hormone (melatonin, endothelin and alfa-MSH) concentrations, for increasing periods of time. (AU)