Deciphering thermoregulation responses in sheep: genomic characterization of physiological versatility

• Grant number: 19/12604-4
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2020
• End date: March 31, 2022
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Ecology of Domestic Animals and Ethology
• Principal Investigator: Cristiane Gonçalves Titto
• Grantee: Cristiane Gonçalves Titto
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated researchers: Alessandra Fernandes Rosa ; Alfredo Manuel Franco Pereira ; Evaldo Antonio Lencioni Titto ; Gerson Barreto Mourão ; Heidge Fukumasu ; Lina Fernanda Pulido Rodriguez ; Mirele Daiana Poleti ; Raluca Mateescu

Abstract

The effects of climate changes are controversial. The uncertainty of climate changes and how these alterations will affect animal production on a global scale is largely unknown. Much is known about thermal effects of heat stress on health and reproductive performance. However, there are only a few studies about animal adaptation to extreme weather events or to faster climate changes. Thus, the concept of "adapted animal" should emphasize to physiological versatility. The study is based on the assumption that an animal with greater physiological versatility has comparative advantages before climate irregularities and that also provides an increased tolerance to environmental stress, in particular to heat. The overall objective of the study is to characterize the physiological versatility of sheep breed, through thermoregulatory and cellular responses, in biomarkers and morphological and endocrine changes resulting from such proceedings acclimatization. It will be used 80 sheep of the black Santa Ines breed, with similar age and weight. The study will be carried out in the summer with animals from pastures with access to shade. The animals will be kept for 7 days in a climatic chamber with a temperature varying from 24 to 36°C, where the heat cycle starting at 10 hours and ending at 16 hours with maintenance of 24°C from 16 h to 10 h. Evaporative thermolysis pathways and circadian cycles of heat stores will be studied to define the 12 most heat tolerant animals and the 12 least heat tolerant animals. In these 24 animals will be evaluated the concentrations of thyroid hormones, cortisol, and insulin. Skin samples will be collected for histological examination in order to evaluate the structure and morphology of the sweat glands and the degree of vascularization in the basal period and after prolonged stress. Skin and blood (12h) samples will be used for RNA sequencing analysis to evaluate the gene expression of possible genes involved in heat tolerance. In the future, these characteristics will be used to select animals that are more tolerant to thermal stress. (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)

PANTOJA, MESSY HANNEAR DE ANDRADE; CAMPOS, JESSICA CAETANO DIAS; DE ALMEIDA, DOUGLAS HENRIQUE SILVA; NEGRAO, JOAO ALBERTO; MOURAO, GERSON BARRETO; PEREIRA, ALFREDO MANUEL FRANCO; TITTO, CRISTIANE GONSALVES. Influence of successive heat waves on the thermoregulatory responses of pregnant and non-pregnant ewes. Journal of Thermal Biology, v. 111, p. 6-pg., 2023-01-01. (19/22226-7, 19/12604-4)