Breeding & Genetics and Physiology & Endocrinology Symposium: Bridging the Gap Between Physiology and Genomics

Since the dawn of modern genetics, researchers have been working toward the elucidation of genetic pathways that control variation in traits of interest. Along the way, new breakthroughs in technology have lead to new insights. The determination of the structure of DNA and the subsequent explosion in molecular biology, enabled researchers to identify genes responsible for many processes in a cell (e.g., glycogenesis, transcription, etc). Eventually, geneticists began to utilize these new molecular techniques to identify regions of the genome that contain genetic variation that was associated with phenotypic variation (quantitative trait loci; QTL). To date, molecular geneticists have identified almost 10,000 QTL in cattle, pigs and chickens. The speed with which new QTL are identified is ever increasing. Unfortunately, the identification of quantitative trait nucleotides (QTN) lags significantly behind. However, now that the genomes of all major livestock species have been sequenced a new suite of techniques have been unleashed. New genotyping and statistical techniques have made it possible to not only identify QTL and fine map them, but to also account for a large amount of total genetic variation associated with a trait of interest. For some traits there are a large number of small effect QTL (i.e., infinitesimal model), while for other traits there appear to be a limited number of QTL. In addition to genotyping and statistical breakthroughs, whole, or even partial, genome re-sequencing and transcriptomics (RNA-seq) are providing new insights into genome and gene structure. We can now combine phenotype, genotype and gene expression data to understand the mechanisms underlying traits of interest in greater detail than ever before. We have entered an era where molecular/quantitative genetic techniques need to be directed beyond production to consider animal health, animal welfare, climate change mitigation, and consumer health traits.