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Nelore cattle

Genes for lean meat

Nelore: energy metabolism influences muscle shape

Gisele ROSSO / EmbrapaNelore: energy metabolism influences muscle shapeGisele ROSSO / Embrapa

Although Nelore cattle (Bos taurus indicus)—the predominant breed in Brazil today, numbering nearly 210 million head—are quite well-adapted to tropical climates, their meat is still not sufficiently tender to satisfy the most demanding consumers. A team from the Luiz de Queiroz College of Agriculture at the University of São Paulo (ESALQ-USP), led by Luiz Coutinho, along with researchers from the Agriculture Informatics unit of the Brazilian Agricultural Research Corporation (Embrapa), and the University of Munich, Germany, examined the genes of 723 Nelore males. The conclusion is that the variation in the number of copies of large DNA segments having a minimum length of 1,000 base pairs could have a direct influence on the quality of the meat (PLOS One, June 27, 2016). The analyses showed 1,155 regions with repeated DNA segments in 2,750 genes—the equivalent of 6.5% of the bovine genome. Several repeated or deleted regions were associated with genes involved in the energy metabolism of the hydrogenated compound guanosine triphosphate and the antioxidant glutathione, which are known to influence muscle shape and function. Other repetitions occurred in the genes of the hormone somatotropin, associated with the growth and differentiation of muscle cells. These data can provide help in choosing lineages of animals capable of producing tenderer meat. Tenderness, first investigated more than a century ago, is also enhanced by large muscle fibers, and negatively affected by environmental stress.