Location: Nutrition, Growth and Physiology
Title: Genes involved in the cholecystokinin receptor signaling map were differentially expressed in the jejunum of steers with variation in residual feed intakeAuthor
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KERN-LUNBERY, REBECCA - Ward Laboratories |
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RATHERT-WILLIAMS, ABIGAIL - University Of Missouri |
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FOOTE, ANDREW - Oklahoma State University |
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CUNNINGHAM-HOLLINGER, HANNAH - University Of Wyoming |
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Kuehn, Larry |
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MEYER, ALLISON - University Of Missouri |
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Lindholm-Perry, Amanda |
Submitted to: Veterinary and Animal Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/13/2024 Publication Date: 6/3/2024 Citation: Kern-Lunbery, R.K., Rathert-Williams, A.R., Foote, A.P., Cunningham-Hollinger, H.C., Kuehn, L.A., Meyer, A.M., Lindholm-Perry, A.K. 2024. Genes involved in the cholecystokinin receptor signaling map were differentially expressed in the jejunum of steers with variation in residual feed intake. Veterinary and Animal Science. 24. Article 100357. https://doi.org/10.1016/j.vas.2024.100357. DOI: https://doi.org/10.1016/j.vas.2024.100357 Interpretive Summary: The small intestine is important for nutrient digestion and absorption. Differences in the ability of the small intestine of beef cattle to take up nutrients is likely to affect feed efficiency. The purpose of this study was to determine whether there were differences in the genes expressed in the small intestine of beef steers contributing to feed efficiency in two groups of steers. Small intestine samples from one cohort of steers were sequenced for gene expression, and a total of 32 genes were identified as differentially expressed. These genes are involved in metabolic and cellular pathways including cholecystokinin receptor (CCKR) signaling, p38 MAPK pathways, inflammatory mediator pathways. The CCKR signaling map pathway identified is involved in digestion, appetite control and the regulation of body weight making it a compelling candidate for feed efficiency in cattle. Validation of nine of the differentially expressed genes in the two groups of steers supports a potential relationship between most of these genes and feed efficiency status. Technical Abstract: The jejunum is a critical site for nutrient digestion and absorption, and variation in its ability to take up nutrients within the jejunum is likely to affect feed efficiency. The purpose of this study was to determine differences in gene expression in the jejunum of beef steers divergent for residual feed intake (RFI) in one cohort of steers (Year 1), and to validate those genes in animals from a second study (Year 2). Steers from Year 1 (n = 16) were selected for high and low RFI. Jejunum mucosal tissue was obtained for RNA-seq. Thirty-two genes were differentially expressed (PFDR=0.15), and five were over-represented in pathways including inflammatory mediator, cholecystokinin receptor (CCKR) signaling, and p38 MAPK pathways. Several differentially expressed genes (ALOX12, ALPI, FABP6, FABP7, FLT1, GSTA2, MEF2B, PDK4, SPP1, and TTF2) have been previously associated with RFI in other studies. Real-time qPCR was used to validate nine differentially expressed genes in the Year 1 steers used for RNA-seq, and in the Year 2 validation cohort. Six genes were validated as differentially expressed (P < 0.1) using RT-qPCR in the Year 1 population. In the Year 2 population, five genes displayed the same direction of expression as the Year 1 population and 3 were differentially expressed (P < 0.1). The CCKR pathway is involved in digestion, appetite control, and regulation of body weight making it a compelling candidate for feed efficiency in cattle, and the validation of these genes in a second population of cattle is suggestive of a role in feed efficiency. |