title: 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 real-time 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.
authors.affiliation: Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Wanju, Jeollabuk-do, 565-851, Korea.
authors.forename: Krishnamoorthy
authors.initials: K
authors.lastname: Srikanth
authors.affiliation: Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Wanju, Jeollabuk-do, 565-851, Korea.
authors.forename: Anam
authors.initials: A
authors.lastname: Kwon
authors.affiliation: Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Wanju, Jeollabuk-do, 565-851, Korea.
authors.forename: Eunjin
authors.initials: E
authors.lastname: Lee
authors.affiliation: Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Wanju, Jeollabuk-do, 565-851, Korea. chung133@korea.kr.
authors.forename: Hoyoung
authors.identifier: 0000-0002-5205-193X
authors.initials: H
authors.lastname: Chung
mesh_terms: D000818:Animals; D001831:Body Temperature; D002417:Cattle; D016000:Cluster Analysis; D015536:Down-Regulation; D005298:Fertility; D020869:Gene Expression Profiling; D053263:Gene Regulatory Networks; D018869:Heat-Shock Response / Q000235:genetics*; D007107:Immune System / Q000378:metabolism; D018832:Molecular Chaperones / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012313:RNA / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D017423:Sequence Analysis, RNA; D015398:Signal Transduction; D013696:Temperature; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome; D015854:Up-Regulation
chemical_list: D018832:Molecular Chaperones; D014157:Transcription Factors; D012313:RNA; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt
keywords: Differentially expressed genes; Heat stress; KEGG; RNAseq; Transcriptome