Evaluation of the relationship of potential skin genes linked to thermotolerance in Santa Inês sheep

Abstract

There is much knowledge about the effects of heat stress on health, reproduction, and performance. However, studies on the adaptation of animals to extreme weather events or faster climate change and the role of genes in these responses are scarce. The general objective of the study is to evaluate the existing relationships between potential genes in the skin related to heat stress in Santa Inês ewes during heat stress in a climatic chamber. The experiment will be conducted at the Campus Fernando Costa (FZEA) of the University of São Paulo, Brazil. 24 animals will be used, considered the extremes of an initial group of 80 sheep, being classified as the 12 animals more tolerant to heat and the 12 animals less tolerant to heat. The animals will undergo a ten-day climate chamber cycle. In the first two days, the animals will adapt to the new environment. From the third to the last day, heat treatment (stress factor) will be carried out, and the climate chamber will be connected with a temperature of 36 °C starting at 10:00 am to 4:00 pm, with maintenance of 28 °C from 4:00 pm to 10:00 am. On the first and last day, the rectal temperature will be measured using a digital clinical thermometer at 1:00 pm, 4:00 pm, 7:00 pm, 9:00 pm, 1:00 am, 4:00 am, 7:00 am and 10:00 am. On the last day, a skin sample will be collected and kept in RNA later for further RNA sequencing. The gene expression in skin samples and its relationship with immune systems, antioxidant profile, stress biomarkers, skin gene expression, and genomic profiles will be evaluated. In order to select the potential modules of biological interest, Pearson's Moment-Product correlation analyzes will be performed between the modules and the heat tolerance characteristics. (AU)