A reference genome is a high-quality genetic map, providing a foundational understanding of a species’ biology. This complete DNA sequence acts as a standard for comparing all other genetic data. For pigs, this genetic blueprint holds significant economic and scientific value, influencing agriculture and medical research.
What is the Pig Reference Genome?
The pig reference genome is a complete, publicly available DNA sequence of the domestic pig, Sus scrofa, serving as a standardized map for genetic comparison. Its creation was a collaborative international undertaking, spearheaded by the Swine Genome Sequencing Consortium (SGSC), established in 2003 to coordinate global sequencing efforts.
The pig, Sus scrofa, was selected for mapping due to its importance as food and biological similarities to humans. The first draft, Sscrofa10.2, was released in 2012, with an improved assembly, Sscrofa11.1, published in 2017. This reference assembly, derived from a purebred Duroc female pig, consists of 20 chromosomes, with an estimated haploid genome size of approximately 2800 Mb.
Unlocking Agricultural Improvements
The pig reference genome has revolutionized pig farming by enabling precise selective breeding for desirable agricultural traits. It allows for identifying specific genes and genetic markers linked to traits like faster growth, improved meat quality, disease resistance, and reproductive efficiency. For instance, studies have identified genetic loci associated with growth and backfat traits in breeds like the Large White pig.
Understanding the pig’s genetic makeup facilitates selecting breeding animals that pass beneficial traits to offspring, leading to healthier, more productive herds. Research has pinpointed genomic regions affecting pork tenderness, intramuscular fat, and loin eye area. This genetic insight supports sustainable agricultural practices by reducing time and resources to market animals and minimizing disease losses. Genomic selection, using thousands of single nucleotide polymorphisms (SNPs) to predict traits, can increase genetic progress by up to 35% annually.
Insights for Human Health
Pigs serve as valuable biomedical models for human health research due to their physiological and anatomical similarities to humans. Their organ size, cardiovascular system, digestive tract, and skin resemble humans’. The pig genome’s genetic analogy to the human genome, with pigs having approximately 3.0 billion base pairs compared to humans’ 3.5 billion base pairs, enhances their utility for studying human conditions.
The pig reference genome facilitates investigating human diseases like cardiovascular conditions, metabolic disorders such as diabetes, and genetic conditions like cystic fibrosis and retinitis pigmentosa. It aids in developing treatments and testing drug efficacy, as pig models mimic human disease progression more accurately than rodent models. In regenerative medicine, especially xenotransplantation, genetically engineered pigs are developed as organ donors to address the human organ shortage. These modifications include deleting genes that cause immune rejection and inserting human genes to improve compatibility, focused on organs like hearts and kidneys.