The goal of the work reported herein was to investigate if a new methodology could provide gene expression profiles of brachiocephalicus muscle tissue from young steers and to compare this genetic expression with carcass traits determined at slaughter to identify potential candidate genes. Tissue samples were collected from steers using a fine needle biopsy from muscle in the neck region at weaning. Muscle tissue was removed using the Dunn Biopsy method, and RNA was extracted for sequencing and transcriptomic analysis. Animal groups for data analysis were designated using marbling score codes (MSC) established from carcass grade at slaughter, which identified DNER, PCBD1 and BGN genes associated with adipose; muscle genes included MAP7, PDE1B, and ADAMTS2; tenderness genes identified were FMO2 and ZKSCAN2; and marbling genes RPTN, DNER, and CACNA2D2. These results indicate muscle biopsies may yield complementary information associated with carcass traits to the current industry standards. Application of this technique may provide insight to the identification of candidate genes that could improve production decisions, increase accuracy of prediction from transcriptomic profiling, and ultimately speed genetic progress.

In mammary gland development, normal stem cell activity occurs in the embryonic stage and postnatally. Research supports that certain breast cancers contain a small sub-population of cells that mimic stem-like activity. It is believed stem cell activation in the mutated mature human mammary tissue is what drives quiescent epithelial cells to convert to mesenchymal states initiating migration, invasion, and metastasis in breast cancer. The goal of the work reported herein was to investigate early mammary development gene expression in the postnatal pig using fine needle biopsy methods in order to establish a reliable model for human breast cancer detection. Tissue samples were collected from pig mammary glands beginning at Day 11 of age through Day 39 in order to capture early postnatal-growth gene expression. Based on the initial clustering analysis, two distinct clusters of gene expression profiles occurred before and after Day 25 of mammary development. Gene set enrichment analysis (GSEA) ontology indicated the cellular processes that changed after Day 25, and many of these processes were implicated in epithelial–mesenchymal transition (EMT) signaling events. Gene expression in the postnatal pig was compared with the Epithelial–Mesenchymal Transition gene database (dbEMT) confirming the presence of EMT activity in this early developmental program. Information from this study will provide insight into early postnatal mammary gland development. In addition, mechanisms exploited by mutated mammary epithelial cells leading to cancer initiation and growth may be detected considering that mutated mammary epithelial cells can reactivate early developmental signals.