Location: Livestock Bio-SystemsTitle: Genome-wide association of myoglobin concentrations in pork loins
|CROSS, AMANDA - South Dakota State University|
|King, David - Andy|
|Nonneman, Danny - Dan|
Submitted to: Meat and Muscle Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2018
Publication Date: 7/2/2018
Publication URL: https://handle.nal.usda.gov/10113/6472426
Citation: Cross, A.J., King, D.A., Shackelford, S.D., Wheeler, T.L., Nonneman, D.J., Keel, B.N., Rohrer, G.A. 2018. Genome-wide association of myoglobin concentrations in pork loins. Meat and Muscle Biology. 2(1):189-196. https://doi.org/10.22175/mmb2017.08.0042.
Interpretive Summary: Pork quality is a concern for producers, packers, retailers, and consumers. Lean meat color is a major focus for consumers as they often associate color with freshness. Myoglobin is the primary pigment resulting in the red color of pork. In order to increase redness of pork, increasing myoglobin concentration is important. Therefore, we must understand genetic factors that affect myoglobin concentration to enable improving pork color. The objective of this study was to identify genetic markers associated with myoglobin concentration in pork loin muscle. Ultimate pH and myoglobin concentrations were measured in 599 loin samples of pigs from two different commercial finishing swine facilities. An association analysis identified regions within seven chromosomes that explained over half of the genetic variance in myoglobin concentration. Chromosome 7 had one significant region which accounted for over one third of the genetic variance, while chromosome 14 had three significant regions. Within the region identified we found genes involved in regulating iron or calcium concentrations in muscle. Improving pork color may be possible by monitoring these genes or by using the genetic markers associated with myoglobin in selection decisions
Technical Abstract: Lean color is a major focus for identifying pork loins for export markets, and myoglobin is the primary pigment driving pork color. Thus, increasing myoglobin concentration should increase redness of pork products and the number of loins acceptable for exportation. Therefore, understanding genetic variation and parameters affecting myoglobin concentration is critical for improving pork color. The objective of this study was to identify genetic markers associated with myoglobin concentration in pork loin muscle. Ultimate pH and myoglobin concentrations were measured in longissimus thoracis et lumborum samples of pigs (n = 599) from two different commercial finishing swine facilities. A Bayes-C model implemented in GenSel identified regions within 7 chromosomes that explained greater than 63% of the genetic variance in myoglobin concentration. Chromosome 7 had 1 significant region which accounted for 37% of the genetic variance, while chromosome 14 had 4 significant regions accounting for 9.8% of the genetic variance. Candidate genes in the region on chromosome 7 were involved in iron homeostasis, and genes in the significant regions on chromosome 14 were involved in calcium regulation. Genes identified in this study represent potential biomarkers that could be used to select for higher myoglobin concentrations in pork, which may improve lean meat color.