Characterization of genes and pathways that respond to heat stress in Holstein calves through transcriptome analysis

Abstract

This study aimed to investigate the genes and pathways that respond to heat stress in Holstein bull calves exposed to severe ranges of temperature and humidity. A total of ten animals from 4 to 6 months of age were subjected to heat stress at 37°C and 90 % humidity for 12 h. Skin and rectal temperatures were measured before and after heat stress; while no correlation was found between them before heat stress, a moderate correlation was detected after heat stress, confirming rectal temperature to be a better barometer for monitoring heat stress. RNAseq analysis identified 8567 genes to be differentially regulated, out of which 465 genes were significantly upregulated (≥2-fold, P < 0.05) and 49 genes were significantly downregulated (≤2-fold, P < 0.05) in response to heat stress. Significant terms and pathways enriched in response to heat stress included chaperones, cochaperones, cellular response to heat stress, phosphorylation, kinase activation, immune response, apoptosis, Toll-like receptor signaling pathway, Pi3K/AKT activation, protein processing in endoplasmic reticulum, interferon signaling, pathways in cancer, estrogen signaling pathway, and MAPK signaling pathway. The differentially expressed genes were validated by quantitative realtime PCR analysis, which confirmed the tendency of the expression. The genes and pathways identified in this analysis extend our understanding of transcriptional response to heat stress and their likely functioning in adapting the animal to hyperthermic stress. The identified genes could be used as candidate genes for association studies to select and breed animals with improved heat tolerance.

Genetic diversity and selection signatures of the beef ‘Charolais de Cuba’ breed

“…Another interesting gene is heat shock protein HSPB1 (also known as HSP25 , HSP27 or HSP28 ) located within interval 95. HSPB1 which encodes a small heat shock protein that functions as a molecular chaperone 24 , have been found in numerous studies among genes differentially expressed in heat-stressed animals from different species, including cattle 25 , zebu 26 or buffalo 27 . It is worth noticing that this interval contains ACHE , another candidate gene potentially involved in thermo-tolerance.…”

Heat Stress Impacts Immune Status in Cows Across the Life Cycle

“…More specifically, after heat exposure for 3 to 14 days, circulating IgG was reduced by 27% and the number of peripheral blood lymphocytes was reduced compared with calves that were held at thermoneutrality. Acute heat stress (i.e., 37 • C and 90% humidity for 12 h) exposure of post-weaned dairy calves triggers the expression of genes involved in immune responses and immunity-related signaling pathways (84). Several immune-related pathways, such as Tolllike receptor, T-and B-cell receptor signaling pathways, as well as antigen processing and presentation pathways were upregulated in the blood in response to acute heat stress.…”

Clinical Ketosis-Associated Alteration of Gene Expression in Holstein Cows

“…Nevertheless, the association between difference in gene expression and incidence and progression of ketosis remains unknown. The 'Omics' technologies of transcriptomics, metabolomics, and proteomics have increasingly been used to investigate the underlying molecular mechanism of complex diseases in cattle, such as hyperthermic stress [21], mastitis [22], footrot [23], and lipid metabolome disorder [24]. In these studies, whole blood has been widely used due to convenient and non-invasive sampling.…”