Thermal challenge alters the transcriptional profile of the breast muscle in turkey poults

Abstract

&NA; Extremes in temperature represent environmental stressors that impact the well‐being and economic value of poultry. As homeotherms, young poultry with immature thermoregulatory systems are especially susceptible to thermal extremes. Genetic variation and differences in gene expression resulting from selection for production traits, likely contribute to thermal stress response. This study was designed to investigate in vivo transcriptional changes in the breast muscle of young turkey poults from an unselected randombred line and one selected for 16 wk body weight under hot and cold thermal challenge. Newly hatched turkey poults were brooded for 3 d at one of 3 temperatures: control (35°C), cold (31°C), or hot (39°C). Samples of the pectoralis major were harvested and subjected to deep RNA sequencing. Significant differential gene expression was observed in both growth‐selected and randombred birds at both temperature extremes when compared to control‐brooded poults. Growth‐selected birds responded to thermal stress through changes in genes predicted to have downstream transcriptional effects and that would result in reduced muscle growth. Slower growing randombred birds responded to thermal stress through modulation of lipid‐related genes, suggesting reduction in lipid storage, transport, and synthesis, consistent with changes in energy metabolism required to maintain body temperature.