Differential Exon Usage in Expression Profiles from Stress Axis Tissues of Brahman Cows Subjected to Prenatal Stress

Alteration in gene expression caused by stress may serve as a potential mechanism behind a range of differences previously observed in progeny exposed to prenatal stress. The objective of this study was to examine the impact of prenatal transportation stress on differential exon usage in expressed genes of stress-axis tissues of control and prenatally stressed Brahman cattle at five years of age.

Pregnant Brahman cows were transported for 2 h sessions at 20-day intervals from the 60th to the 140th day of gestation, while pregnant herdmates served as controls. Blood samples were collected from six prenatally stressed (PNS) and eight control (control) females obtained when they were 5 years of age. Tissue samples were harvested from the adrenal medulla, adrenal cortex, anterior pituitary and hypothalamic paraventricular nucleus of the PNS and control cows at 5 years of age. Differential exon usage was analyzed by the DEXSeq tool to identify genes that were not previously identified by RNA sequencing analyses.

Differential exon usage (FDR ≤ 0.05) was detected in three exons (two genes) in the adrenal medulla, six exons (five genes) in the adrenal cortex, 13 exons (12 genes) in the anterior pituitary, and 37 exons (33 genes) in the hypothalamic paraventricular nucleus.

The correspondence of prenatal stress to changes in exon usage across multiple tissues and genes could indicate investigative opportunities in postnatally affected physiological processes, including myelination, brain development, stress responses and metabolism.