Seasonality and photoperiodism in South American subterranean rodents under field and laboratory conditions

• Grant number: 19/26752-5
• Support Opportunities: Regular Research Grants
• Duration: February 01, 2021 - January 31, 2023
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Gisele Akemi Oda
• Grantee: Gisele Akemi Oda
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Verônica Sandra Valentinuzzi

Abstract

In this Brazil/Argentina collaboration project, we intend to investigate the seasonality in physiological and behavioral aspects of subterranean rodents (Ctenomys aff. knighti). In the first 10 years of this research, our chronobiological fieldwork was mostly carried out in large semi-natural arenas. We have finally achieved the technical conditions to perform free-living physiological and behavioral rhythm measurements of these endemic South American animals. We will perform: in free-living (field): recordings of seasonal patterns of daily underground and surface activity, as well as light-exposure using bio-logging; the reproductive status of tuco-tucos through the fecal metabolite profiles of reproductive hormones and morphology of the genitals. In semi-natural arenas: To verify and characterize the seasonal thermoregulatory strategy of "daily torpor", continuous recordings of deep body temperature (Tc), surface and underground locomotor activity using bio-logging will be made in winter and summer. In the laboratory: 1) analysis of the behavioral temporal patterns of the tuco-tucos through the association between data obtained by accelerometers and filming; 2) analysis of circadian clock gene expression in different regions of the suprachiasmatic nuclei of tuco-tucos captured in summer and winter (collaboration with U. Washington). 3) fecal metabolite profiles of reproductive, thyroid and stress hormones throughout the year under natural photoperiod and constant ambient temperature of 22ºC. In mathematical modeling: computer simulations to verify lighting regimes with minimum light pulse frequency sufficient for a two coupled oscillator system (representing two regions of the suprachiasmatic nuclei) to process the photoperiod of each season. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

FLORES, DANILO E. F. L.; JANNETTI, MILENE G.; IMPROTA, GIOVANE C.; TACHINARDI, PATRICIA; VALENTINUZZI, VERONICA S.; ODA, GISELE A.. Telling the Seasons Underground: The Circadian Clock and Ambient Temperature Shape Light Exposure and Photoperiodism in a Subterranean Rodent. FRONTIERS IN PHYSIOLOGY, v. 12, OCT 1 2021. (17/16242-4, 10/03565-0, 19/26752-5, 16/25968-6, 17/19680-2, 16/25058-0, 17/22973-1)