Scientists at the France's government-funded agricultural research institute (INRA) said they have discovered a relationship between the expression of a gene (DNAJA1) and meat toughness. The tenderness of beef, its flavour and its taste, depend not only on slaughter conditions and the ageing of meat, but also on the biological characteristics of muscle, which in turn are linked to the genetic traits of the animal, its rearing conditions and particularly its diet. However, the biological criteria used until now have been insufficient to explain the considerable variations observed in beef quality, the scientists stated. The lack of data has made it difficult to ensure a processing plant gets a consistent quality of meat. The results, which have now been patented, open the way to developing a genetic or immunological test which could identify cattle with potential to produce tender meat, the scientists stated on the INRA internet site. The size and shape of a piece of beef, its colour, the amount of fat visible and the fineness of its texture are the principal criteria which, together with the purchase price, condition consumer choice. However, these characteristics do not provide information as to the sensory qualities of the meat - including tenderness, juiciness and flavour after cooking. About 30 per cent of the variability of meat tenderness can be explained by differences in the muscle characteristics of animals, the scientists stated. "Identifying new biological characteristics of muscle with a marked influence on meat quality is thus a major challenge for the butchery industry, particularly since these criteria could be integrated in breeding schemes for cattle," the scientists suggested. The scientists analysed the expression profiles of genes in muscles from 14 Charolais bull calves. These animals resulted from divergent breeding for muscle growth potential, considered to improve tenderness. The transcriptomes of all the genes expressed of the forerib muscles were analysed using DNA chips and compared on the basis of sensory qualities and muscle growth potential. The researchers claim to have demonstrated a negative relationship between expression of the DNAJA1 gene and meat tenderness as assessed by a tasting panel. The level of expression of this gene explained up to 63 per cent f the difference in tenderness, they stated. "The Hsp 40 protein coded by this gene may therefore contribute to slowing the process of cell death (apoptosis), thus diminishing meat ageing, a process which encourages it to become more tender during the days following slaughter of the animal," they stated. "Expression of this gene thus constitutes a negative marker for tenderness." The patent was filed in September 2006. The scientists are now trying to validate the relationship between the expression of DNAJA1 and meat tenderness in a larger population of breeds. "This work should result in the development of a simple, routine test which can be used at an industrial scale to identify cattle with the potential to produce tender meat," they stated. The work by Bernard C., Cassar-Malek I., Le Cunff M., Dubroeucq H., Renand G., Hocquette J.F. is published in the Journal of Agricultural and Food Chemistry (55. 5229-5237).