Testis-specific changes in gene expression of post-pubertal beef bulls divergent for residual feed intake and exposure to different pre-natal diets

Abstract

Context Selection for residual feed intake (RFI) and its impact on male reproductive development has had mixed reviews in the past. Our previous studies demonstrated earlier puberty, larger testes and greater percentage of progressively motile sperm in high-RFI bulls. However, the molecular mechanisms within testes of bulls with varying RFI remain unclear. Aims To determine the effect of RFI and pre-natal diet on the expression patterns of testicular genes and use this information to explain differences observed across RFI. Methods The study included 25 purebred-Angus bulls with a genetic background of either high or low RFI and fed either normal or low pre-natal nutrition from 30 to 150 days post conception. After slaughter (17 months), testicular tissue was recovered, and RNA was extracted and sequenced. Key results Of 19218 expressed genes, 17 were differentially expressed for RFI (including PLCD1, INPP4B), with no differences being observed for pre-natal diet or diet × RFI interaction (false discovery rate) < 0.1%). KEGG pathway analysis indicated that differentially expressed genes were associated with inositol phosphate metabolism, and phosphatidylinositol signalling. On the basis of a candidate gene-expression study, IGF1R was upregulated in high-RFI bulls (P < 0.1). Conclusions Increased expression of IGF1R and lowered PLCD1 and INPP4B expression could activate PI3K–Akt signalling responsible for cell growth, proliferation and steroid metabolism in high-RFI bulls. Implications Selecting bulls for feed efficiency might affect molecular networks associated with reproduction and fertility.

Exploring Biological Impacts of Prenatal Nutrition and Selection for Residual Feed Intake on Beef Cattle Using Omics Technologies: A Review

“…As mentioned earlier, it is important to ensure that selection for RFI in cattle does not negatively affect their reproductive capacity. Johnson et al (2020) identified 17 differentially expressed genes involved in molecular networks associated with reproduction and fertility in testis of divergent RFI Angus bulls. Of particular interest were insulin like growth factor 1 receptor [ IGF1R ], phospholipase C delta 1 [ PLCD1 ], and inositol polyphosphate-4-phosphatase type II B [ INPP4B ], where higher expression of IGF1R and lower expression of PLCD1 and INPP4B could activate PI3K–Akt signaling responsible for cell growth, proliferation and steroid metabolism in HRFI bulls.…”

“…To date only two published articles have evaluated the impact of the interaction between both prenatal diet and RFI on gene expression. Johnson et al (2020) used RNA-seq to identify differentially expressed genes in testis of bull offspring born from divergent RFI parents, of which the pregnant females were also exposed to differential planes of prenatal nutrition during the first half of gestation. These authors did not detect any genes that were significantly affected by both parental RFI and prenatal nutrition in testis.…”