Transcriptome analysis reveals potential mechanisms underlying differential heart development in fast- and slow-growing broilers under heat stress

BMC Genomics

Research Article

Susan J Lamont¹  Jibin Zhang¹  Carl J Schmidt² 

[1] Department of Animal Science, Iowa State University, 806 Stange Rd, 2255 Kildee Hall, 50011, Ames, IA, USA;Department of Animal and Food Sciences, University of Delaware, 531 South College Ave, 19716, Newark, DE, USA;

关键词: RNA-seq;    Broilers;    Heart;    Heat stress;    Gene expression;    Cell cycle;    Illinois;    Ross;    Polo-like Kinase;    Pathways;   

DOI  :  10.1186/s12864-017-3675-9

 received in 2016-08-19, accepted in 2017-04-01,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundModern fast-growing broilers are susceptible to heart failure under heat stress because their relatively small hearts cannot meet increased need of blood pumping. To improve the cardiac tolerance to heat stress in modern broilers through breeding, we need to find the important genes and pathways that contribute to imbalanced cardiac development and frequent occurrence of heat-related heart dysfunction. Two broiler lines – Ross 708 and Illinois – were included in this study as a fast-growing model and a slow-growing model respectively. Each broiler line was separated to two groups at 21 days posthatch. One group was subjected to heat stress treatment in the range of 35–37 °C for 8 h per day, and the other was kept in thermoneutral condition. Body and heart weights were measured at 42 days posthatch, and gene expression in left ventricles were compared between treatments and broiler lines through RNA-seq analysis.ResultsBody weight and normalized heart weight were significantly reduced by heat stress only in Ross broilers. RNA-seq results of 44 genes were validated using Biomark assay. A total of 325 differentially expressed (DE) genes were detected between heat stress and thermoneutral in Ross 708 birds, but only 3 in Illinois broilers. Ingenuity pathway analysis (IPA) predicted dramatic changes in multiple cellular activities especially downregulation of cell cycle. Comparison between two lines showed that cell cycle activity is higher in Ross than Illinois in thermoneutral condition but is decreased under heat stress. Among the significant pathways (P < 0.01) listed for different comparisons, “Mitotic Roles of Polo-like Kinases” is always ranked first.ConclusionsThe increased susceptibility of modern broilers to cardiac dysfunction under heat stress compared to slow-growing broilers could be due to diminished heart capacity related to reduction in relative heart size. The smaller relative heart size in Ross heat stress group than in Ross thermoneutral group is suggested by the transcriptome analysis to be caused by decreased cell cycle activity and increased apoptosis. The DE genes in RNA-seq analysis and significant pathways in IPA provides potential targets for breeding of heat-tolerant broilers with optimized heart function.

【 授权许可】

CC BY   
© The Author(s). 2017