Collagens XII and XIV: Two collagen types both associated with bovine muscle and intramuscular lipid metabolism

In continental Europe, intramuscular fat (IMF) content in beef is low but plays a key role in determining flavor. IMF expands inside the extracellular matrix (ECM) of intramuscular connective tissue. This ECM contains among others, collagens XII and XIV, two minor collagens probably involved in muscle metabolism. So, our purpose was to determine if there was an association between the contents in collagens XII and XIV and muscle metabolism. Rectus abdominis (RA, oxidative) and Semitendinosus (ST, oxido-glycolytic) muscles were sampled from steers of two genotypes with high (Angus [Ang], n=10) or low (Limousine [Lim], n=10) intramuscular fat level. Collagens XII and XIV relative abundance was evaluated by Western blot analysis. The characteristic parameters of metabolism were previously measured. Ang muscles contained more collagen XIV than Lim muscles (p<0.001). RA muscle contained more collagen XII than ST muscle (p<0.01). Across the two breeds and muscles, collagen XII was positively correlated with A- and H-fatty acid binding protein (FABP) contents (+0.43 and +0.53, respectively, p<0.05) and activities of three oxidative enzymes (cytochrome-c oxidase: +0.41, isocitrate dehydrogenase [ICDH]: +0.40, citrate synthase [CS]: +0.32) (p<0.05) and collagen XIV was positively correlated with triacylglycerol content (+0.35, p<0.35), A- and H-FABP protein contents (+0.35 and +0.38, respectively, p<0.05) and ICDH (+0.34, p<0.05) and negatively with activities of two enzymes of glycolytic metabolism (phosphofructokinase: -0.31 and lactate dehydrogenase: -0.42, p<0.05). After removing the genotype and muscle effects, only collagen XII remained correlated with A- and H-FABP and CS activity (+0.30, +0.34 and +0.46, respectively, p<0.0505). H-FABP is expressed in various tissues but predominantly in cardiac and oxidative skeletal muscles, whereas A-FABP is exclusively expressed within adipocytes. From these results, we can conclude that collagen XII and XIV are both associated with bovine muscle fiber and intramuscular lipid metabolism, but probably by different mechanisms. As a matter of fact, collagens XII is associated with intramuscular fat differentiation (from its correlation with A-FABP content) and oxidative metabolism (from its correlation with H-FABP content and CS activities) regardless of breed and muscle, whereas type XIV collagen is associated with the same parameters plus enzymes of glycolytic metabolism that discriminate breeds

Repercussions of growth path on carcass characteristics, meat colour and shear force in Alentejana bulls

The aim of this study was to evaluate the carcass and meat characteristics of eight muscles from bulls with distinct growth paths. A total of 40 Alentejana male calves were allocated to two distinct feeding regimes. In the continuous growth (CG) system, the animals were fed concentrates plus hay and were slaughtered at 18 months of age. On the other hand, in the discontinuous growth (DG) system, the animals were fed hay until 15 months of age; the cattle were then fed the same diet provided to the CG group from 15 to 24 months of age. The DG reduced hot carcass weight, fatness and dressing %, but the proportions of fat, bone and muscle tissues in the leg were not affected. In contrast, there was a positive impact of compensatory growth on supraspinatus, triceps brachii, semitendinosus, biceps femoris muscle tenderness, overcoming the negative effects of age at slaughter. The reasons for such improvement in meat tenderness were not related to intra-muscular fat content or myofibrillar protein degradation values. An association between tenderness and muscle collagen properties was not established. The results indicate that the compensatory growth has a muscle-dependent effect

European cattle breed cluster accordingly to their meat quality parameters

The concept of breed is rather questionable and it's used more as a tool for "labelling" production systems than as a biological category. Here, production system is intended as a whole set of animal units, techniques, breeding schemes, marketing, etc. However, man has demonstrated to be very quick in capturing and disseminating good characteristics whence they appear in a breed by mutation or by selection. Therefore, it might be expected that breeds, nevertheless of recent origin, could bear distinguished productive characteristics. Due to the quan- titative nature of them, more characteristics should be measured in order to obtain a clear and statistically significant distinction. We have measured several meat characteristics in 15 European breeds (30 individuals for each breed), mostly with beef attitude, reared in similar conditions. This was accomplished to better reveal the genetic background of breeds. A canonical discriminant analysis showed a clear distinction among breeds. In particular lipid composition of meat was able to assign individuals to breeds with 57% and 63% of individuals correctly classified respectively for neutral and phospholipids. The classification is generally good for all breeds except for the Spanish ones,indicating probably some crossing in the past for these breeds. Neutral lipids can classify double muscled breeds with high precision (84% and 95% in Asturiana de los Valles and Piedmontese respectively). Tenderness related measures (collagen, µ-calpain, m-calpain, calpastatin, MFI) poorly assign indi- viduals to breeds (average 22%). The good classification of individuals to breeds for lipid composition suggests distinctive genetic features and encourages to look further to genetic determination of fat composition in the meat, as well as to exploit particular breeds to obtain products suitable for categories of consumers needing/searching for special components in their diet

Perinatal health monitoring through a European lens: eight lessons from the Euro-Peristat report on 2015 births

International audienceNo abstract availabl

Attitudes to in vitro meat:A survey of potential consumers in the United States

Positivity towards meat consumption remains strong, despite evidence of negative environmental and ethical outcomes. Although awareness of these repercussions is rising, there is still public resistance to removing meat from our diets. One potential method to alleviate these effects is to produce in vitro meat: meat grown in a laboratory that does not carry the same environmental or ethical concerns. However, there is limited research examining public attitudes towards in vitro meat, thus we know little about the capacity for it be accepted by consumers. This study aimed to examine perceptions of in vitro meat and identify potential barriers that might prevent engagement. Through conducting an online survey with US participants, we identified that although most respondents were willing to try in vitro meat, only one third were definitely or probably willing to eat in vitro meat regularly or as a replacement for farmed meat. Men were more receptive to it than women, as were politically liberal respondents compared with conservative ones. Vegetarians and vegans were more likely to perceive benefits compared to farmed meat, but they were less likely to want to try it than meat eaters. The main concerns were an anticipated high price, limited taste and appeal and a concern that the product was unnatural. It is concluded that people in the USA are likely to try in vitro meat, but few believed that it would replace farmed meat in their diet

Identification of New Hematopoietic Cell Subsets with a Polyclonal Antibody Library Specific for Neglected Proteins

The identification of new markers, the expression of which defines new phenotipically and functionally distinct cell subsets, is a main objective in cell biology. We have addressed the issue of identifying new cell specific markers with a reverse proteomic approach whereby approximately 1700 human open reading frames encoding proteins predicted to be transmembrane or secreted have been selected in silico for being poorly known, cloned and expressed in bacteria. These proteins have been purified and used to immunize mice with the aim of obtaining polyclonal antisera mostly specific for linear epitopes. Such a library, made of about 1600 different polyclonal antisera, has been obtained and screened by flow cytometry on cord blood derived CD34+CD45dim cells and on peripheral blood derived mature lymphocytes (PBLs). We identified three new proteins expressed by fractions of CD34+CD45dim cells and eight new proteins expressed by fractions of PBLs. Remarkably, we identified proteins the presence of which had not been demonstrated previously by transcriptomic analysis. From the functional point of view, looking at new proteins expressed on CD34+CD45dim cells, we identified one cell surface protein (MOSC-1) the expression of which on a minority of CD34+ progenitors marks those CD34+CD45dim cells that will go toward monocyte/granulocyte differentiation. In conclusion, we show a new way of looking at the membranome by assessing expression of generally neglected proteins with a library of polyclonal antisera, and in so doing we have identified new potential subsets of hematopoietic progenitors and of mature PBLs