Effect of dietary n-3 polyunsaturated fatty acid supplementation on bovine uterine endometrial and hepatic gene expression of the insulin-like growth factor system.
Supplementation of cattle diets with n-3 polyunsaturated fatty acids (n-3 PUFA) has been suggested to have positive effects on fertility. In addition, the actions of the insulin-like growth factor (IGF) system both systemically and locally have been shown to influence reproductive processes. The objective of this study was to evaluate the effect of dietary n-3 PUFA supplementation on hepatic and endometrial expression of IGF signalling genes in cattle. Beef heifers were supplemented with a rumen protected source of either a saturated fatty acid (palmitic acid; CON) or high n-3 PUFA diet (n-3 PUFA) for 45 days before slaughter and tissue recovery. Transcription level of candidate IGF signalling genes was measured by reverse transcription quantitative real-time PCR (RT-qPCR) in total RNA isolated from uterine endometrial and liver tissue from seven CON and seven n-3 PUFA supplemented animals. Compared to controls, mRNA abundance in n-3 PUFA liver tissues was higher for IGF-2R, IGFBP-1 and IGFBP-5 (P < 0.05); lower for GHR-1A (P < 0.05); and unchanged for IGF-1, IGF-2, IGF-1R, IGFBP-2, IGFBP-3, IGFBP-4, IGFBP-6, ALS and GHR(total) (P > 0.05). Compared to controls, mRNA abundance in n-3 PUFA endometrial tissues was higher for IGF-2, IGF-1R, IGF-2R and IGFBP-2 (P < 0.05); lower for IGF-1, IGFBP-3 and IGFBP-6 (P < 0.05); and unchanged for IGFBP-1, IGFBP-4, IGFBP-5 and GHR(total) (P > 0.05). Thus, dietary supplementation of cattle with n-3 PUFA affects transcription of genes involved in IGF signalling, in a tissue dependent fashion.
Teagasc, Animal Bioscience Centre, Dunsany, Co. Meath, Ireland.
Gerard S
GS
Coyne
David A
DA
Kenny
Sinéad M
SM
Waters
D000818:Animals; D002417:Cattle; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D019587:Dietary Supplements; D004717:Endometrium / Q000737:chemistry / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage* / Q000032:analysis / Q000097:blood; D043371:Fatty Acids, Omega-6 / Q000032:analysis / Q000097:blood; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000235:genetics; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000235:genetics; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000235:genetics; D007335:Insulin-Like Growth Factor II / Q000235:genetics; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D017526:Receptor, IGF Type 1 / Q000235:genetics; D017527:Receptor, IGF Type 2 / Q000235:genetics; D011986:Receptors, Somatotropin / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013002:Somatomedins / Q000235:genetics*
D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D018975:Insulin-Like Growth Factor Binding Protein 5; D012333:RNA, Messenger; D017527:Receptor, IGF Type 2; D011986:Receptors, Somatotropin; D013002:Somatomedins; D007335:Insulin-Like Growth Factor II; D017526:Receptor, IGF Type 1