mRNA Signatures in Peripheral White Blood Cells Predict Reproductive Potential in Beef Heifers at Weaning

Abstract

Reproductive failure is a major contributor to inefficiency within the cow-calf industry. Particularly problematic is the inability to diagnose heifer reproductive issues prior to pregnancy diagnosis following their first breeding season. Therefore, we hypothesized that gene expression from the peripheral white blood cells at weaning could predict the future reproductive potential of beef heifers. To investigate this, the gene expression was measured using RNA-Seq in Angus–Simmental crossbred heifers sampled at weaning and retrospectively classified as fertile (FH, n = 8) or subfertile (SFH, n = 7) after pregnancy diagnosis. We identified 92 differentially expressed genes between the groups. Network co-expression analysis identified 14 and 52 hub targets. ENSBTAG00000052659, OLR1, TFF2, and NAIP were exclusive hubs to the FH group, while 42 hubs were exclusive to the SFH group. The differential connectivity between the networks of each group revealed a gain in connectivity due to the rewiring of major regulators in the SFH group. The exclusive hub targets from FH were over-represented for the CXCR chemokine receptor pathway and inflammasome complex, while for the SFH, they were over-represented for immune response and cytokine production pathways. These multiple interactions revealed novel targets and pathways predicting reproductive potential at an early stage of heifer development.

miRNA expression profiles of peripheral white blood cells from beef heifers with varying reproductive potential

“…We identified 1,365 genes targeted by the 16 DEMIs ( Figure 3 ), out of which 741 were expressed in PWBC ( Supplementary Table S3 ). Out of the 741 genes, nine were previously reported as differentially expressed in PWBC from the same set of FH and SFH heifers ( Supplementary Table S3 ) ( Banerjee et al, 2023 ). The nine genes and their miRNA targets are as follows: bta-miR-92b targeted KLF4 and KAT2B , bta-miR-2419-5p targeted LILRA4 , bta-miR-1260b targeted UBE2E1 , SKAP2 and CLEC4D , bta-let-7a-5p targeted GATM , MXD1 and bta-miR-1839 targeted ESR1 .…”

“…The vacutainers were inverted 8–10 times and immersed in ice until immediate processing. In the laboratory, blood was processed to isolate peripheral white blood cells (PWBC), as described elsewhere ( Banerjee et al, 2023 ). The PWBCs were stored at −80°C until further processing.…”

“…For breeding, 72 heifers were selected based on ideal body condition scores (5–6) and reproductive tract scores (≥4). The breeding protocol, estrus synchronization and fixed-time artificial insemination (AI) have been described previously ( Banerjee et al, 2023 ). In brief, approximately 45 days before breeding by AI, pre-breeding examinations for each heifer were performed to evaluate the pubertal status.…”

“…To identify the correlation pattern between the DEMI-gene targets identified by TargetScan, we also generated PWBC mRNA expression profiles from the same heifers as reported elsewhere ( Banerjee et al, 2023 ). In brief, the mRNA profile of the same set of samples from FH ( n = 7) and SFH ( n = 7) was sequenced to generate paired-end 100 bp reads.…”

Transcriptomic dataset from peripheral white blood cells of beef heifers at weaning

“…Table 1 shows a summary of the metadata, sample description, mapping statistics per sample, and the experimental groups as previously described [1] .…”