Éditeur(s) : HAL CCSD American Society for Biochemistry and Molecular Biology
Résumé : International audience
alpha- and beta-spectrins are components of molecular scaffolds located under the lipid bilayer and named membrane skeletons. Disruption of these scaffolds through mutations in spectrins demonstrated that they are involved in the membrane localization or the maintenance of proteins associated with them. The ubiquitous alphaII-spectrin chain bears in its central region a unique domain that is sensitive to several proteases such as calpains or caspases. The conservation of this region in vertebrates suggests that the proteolysis of alphaII-spectrin by these enzymes could be involved in important functions. To assess the role of alphaII-spectrin cleavage in vivo, we generated a murine model in which the exons encoding the region defining this cleavage sensitivity were disrupted by gene targeting. Surprisingly, homozygous mice expressing this mutant alphaII-spectrin appeared healthy, bred normally, and had no histological anomaly. Remarkably, the mutant alphaII-spectrin assembles correctly into the membrane skeleton, thus challenging the notion that this region is required for the stable biogenesis of the membrane skeleton in nonerythroid cells. Our finding also argues against a critical role of this particular alphaII-spectrin cleavage in either major cellular functions or in normal development.
ISSN: 0021-9258

inserm-00284621
http://www.hal.inserm.fr/inserm-00284621
http://www.hal.inserm.fr/inserm-00284621/document
http://www.hal.inserm.fr/inserm-00284621/file/Meary_-_JBC_2007.pdf
PUBMED : 17374614

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Recent reports suggest that extracellular signal-regulated kinase (ERK1) and ERK2 mitogen-activated protein kinases (MAPK) may direct specific biological functions under certain contexts. In this study, we investigated the role of early and sustained epidermal growth factor (EGF) stimulation on long-term hepatocyte differentiation and the possible role of ERK1 and ERK2 in this process. We demonstrate a long-term survival and an elevated level of differentiation up to 3 weeks. The differentiation state of hepatocytes is supported by sustained expression of aldolase B, albumin, and the detoxifying enzymes CYP1A2, 2B2, and 3A23. Similarly to freshly isolated cells, cultured hepatocytes also retain the ability to respond to 3-methylcholanthrene (3MC) and phenobarbital (PB), two known CYP inducers. In addition, we show evidence that continuous MAPK/ERK kinase (MEK) inhibition enhances the level of differentiation. Using RNA interference approaches against ERK1 and ERK2, we demonstrate that this effect requires both ERK1 and ERK2 activity, whereas the specific ERK1 knockdown promotes cell survival and the specific ERK2 knockdown regulates cell proliferation. In conclusion, we demonstrate that early and sustained EGF stimulation greatly extends long-term hepatocyte survival and differentiation, and that inhibition of the ERK1/2 MAPK pathway potentiates these pro-survival/pro-differentiation phenotypes. We clearly attest that specific ERK1 and ERK2 MAPKs determine hepatocyte survival and proliferation, respectively, whereas dual inhibition is required to stabilize a highly differentiated state.
ISSN: 0021-9541

hal-00681056
https://hal.archives-ouvertes.fr/hal-00681056
DOI : 10.1002/jcp.22742
PUBMED : 21437905

Éditeur(s) : HAL CCSD BioScientifica
Résumé : International audience
Spermatogenesis is a complex and tightly regulated process leading to the continuous production of male gametes, the spermatozoa. This developmental process requires the sequential and coordinated expression of thousands of genes, including many that are testis-specific. The molecular networks underlying normal and pathological spermatogenesis have been widely investigated in recent decades, and many high-throughput expression studies have studied genes and proteins involved in male fertility. In this review, we focus on studies that have attempted to correlate transcription and translation during spermatogenesis by comparing the testicular transcriptome and proteome. We also discuss the recent development and use of new transcriptomic approaches that provide a better proxy for the proteome, from both qualitative and quantitative perspectives. Finally, we provide illustrations of how testis-derived transcriptomic and proteomic data can be integrated to address new questions and how the 'proteomics informed by transcriptomics' technique, by combining RNA-seq and MS-based proteomics, can contribute significantly to the discovery of new protein-coding genes or new protein isoforms expressed during spermatogenesis.
ISSN: 1470-1626

hal-01214005
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01214005
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01214005/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01214005/file/Linking%20transcriptomics%20and%20proteomics%20in%20spermatogenesis.pdf
DOI : 10.1530/REP-15-0073

Résumé : The conservation of crawfish requires the use of chemical substances making it possible to limit blackening. This phenomenon this blackening (melanine) is due to the coordinated action of three elements: - oxygen, - an enzyme (cupro-protein), - a suitable substrate, tyrosin or the dihydroxyphénylalanine. The absence of the one of them allows a notorious reduction in the phenomenon. Several antioxydant products, were used to prevent the formation of the mélanine. The métabisutfite of soda or potassium as well as soda bisulfite in acid solution, are currently used to treat crawfish and shrimps. Several methods of use of these pesticides exist, we propose in this report to present the principal ones, as well as the control methods making it possible to check the quality of the treatment.
La conservation des langoustines nécessite l'utilisation de substances chimiques permettant de limiter le noircissement. Ce phénomène ce noircissement (mélanine) est due à l'action coordonnée de trois éléments : - l'oxygène, - une enzyme (cupro-protéine), - un substrat convenable, la tyrosine ou la dihydroxyphénylalanine. L'absence de l'une d'entre elles permet une diminution notoire du phénomène. Plusieurs produits anti-oxydants, ont été utilisés pour prévenir la formation de la mélanine. Le métabisutfite de soude ou de potassium ainsi que le bisulfite de soude en solution acide, sont actuellement utilisés pour traiter les langoustines et les crevettes. Plusieurs méthodes d'utilisation de ces produits de traitement existent, nous nous proposons dans ce rapport de présenter les principales, ainsi que les méthodes de contrôle permettant de vérifier la qualité du traitement.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1991/rapport-1586.pdf
http://archimer.ifremer.fr/doc/00000/1586/

Éditeur(s) : HAL CCSD Society for the Study of Reproduction
Résumé : International audience
Matrix-assisted laser desorption/ionization (MALDI) tissue imaging mass spectrometry is particularly promising among the numerous applications of mass spectrometry. It is used for probing and analyzing the spatial arrangement of a wide range of molecules, including proteins, peptides, lipids, drugs, and metabolites, directly in thin slices of tissue. In the field of proteomics, the technology avoids tedious and time-consuming extraction and fractionation steps classically required for sample analysis. MALDI imaging mass spectrometry is increasingly recognized as a powerful method for clinical proteomics, particularly in cancer research. The technology has particular potential for the discovery of new tissue biomarker candidates, classification of tumors, early diagnosis or prognosis, elucidating pathogenesis pathways, and therapy monitoring. Over recent years, MALDI imaging mass spectrometry has been used for molecular profiling and imaging directly in male and female reproductive tissues. This review will consider some of the recent publications in the field, addressing a range of issues covering embryo development, gene expression product profiling during gametogenesis, and seeking and identifying biomarkers of reproductive cancers. The wealth of advances in mass spectrometry imaging will inevitably attract biologists and clinicians as the advantages and power of this technology become more widely known. This review will also discuss bottlenecks and the many technical issues that remain to be resolved before laboratories in the field can adopt the technology. We foresee that MALDI imaging mass spectrometry will have a major impact in reproductive research by opening new avenues to the understanding of various molecular mechanisms and the diagnosis of reproductive pathologies.
ISSN: 0006-3363

hal-00877851
https://hal.archives-ouvertes.fr/hal-00877851
DOI : 10.1095/biolreprod.111.094896
PUBMED : 22156474

Éditeur(s) : HAL CCSD
Résumé : International audience
Antiviral proteins that recognize pathogen-specific or aberrantly located molecular motifs are perfectly positioned to act as pattern-recognition receptors and signal to the immune system. Here we investigated whether the interferon-induced viral restriction factor tetherin (CD317/BST2), which is known to inhibit HIV-1 particle release by physically tethering virions to the cell surface, has such a signaling role. We find that upon restriction of Vpu-defective HIV-1, tetherin acts as a virus sensor to induce NFκB-dependent proinflammatory gene expression. Signaling requires both tetherin's extracellular domain involved in virion retention and determinants in the cytoplasmic tail, including an endocytic motif, although signaling is independent of virion endocytosis. Furthermore, recruitment of the TNF-receptor-associated factor TRAF6 and activation of the mitogen-activated protein kinase TAK1 are critical for signaling. Human tetherin's ability to mediate efficient signaling may have arisen as a result of a five amino acid deletion that occurred in hominids after their divergence from chimpanzees.
ISSN: 1934-6069

hal-01121777
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01121777
PUBMED : 23159053
DOI : 10.1016/j.chom.2012.10.007
PUBMEDCENTRAL : PMC3556742

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Although many studies reported mechanisms involved in the positive regulation of estrogens (E2) target genes, very little is known concerning the repressive effect of E2. In this study, we explored the molecular mechanisms by which E2 regulates CXCR7 expression in breast cancer cells. Our results show that E2-mediated down-regulation of CXCR7 occurs at the transcriptional level as demonstrated using actinomycin D and requires estrogen receptor alpha (ERα). In addition, CXCR7 is a primary ERα-target gene because the effect of E2 does not require the synthesis of an intermediary protein as revealed by the translational inhibitor cycloheximide treatment. Using an inhibitor of the NFκB pathway and chromatin immunoprecipitation assays, we demonstrated that NFκB is necessary for the high expression of CXCR7 gene and is recruited to the proximal promoter of the CXCR7 gene. Interestingly, the chromatin immunoprecipitation analyses also showed that E2-treatment significantly prevented the recruitment of NFκB to the promoter. Altogether, our results demonstrate that E2, through ERα, directly down-regulates CXCR7 expression by interfering with NFκB transcription factor at the promoter level.
ISSN: 0006-291X

inserm-00808966
http://www.hal.inserm.fr/inserm-00808966
DOI : 10.1016/j.bbrc.2013.01.050
PUBMED : 23352615

Éditeur(s) : HAL CCSD Society for the Study of Reproduction
Résumé : International audience
Transcription factor GATA4 is required for the development and function of the mammalian gonads. We first reported that the GATA4 gene in both human and rodents is expressed as two major alternative transcripts that differ solely in their first untranslated exon (exon 1a vs. exon 1b). We had also showed by quantitative PCR that in mouse tissues, both Gata4 exon 1a- and 1b-containing transcripts are present in all sites that are normally positive for GATA4 protein. In adult tissues, exon 1a-containing transcripts generally predominate. A notable exception, however, is the testis where the Gata4 exon 1a and 1b transcripts exhibit a similar level of expression. We now confirm by in situ hybridization analysis that each transcript is also strongly expressed during gonad differentiation in both sexes in the rat. To gain further insights into how Gata4 gene expression is controlled, we characterized the mouse Gata4 promoter sequence located upstream of exon 1b. In vitro studies revealed that the Gata4 1b promoter is less active than the 1a promoter in several gonadal cell lines tested. Whereas we have previously shown that endogenous Gata4 transcription driven by the 1a promoter is dependent on a proximally located Ebox motif, we now show using complementary in vitro and in vivo approaches that Gata4 promoter 1b-directed expression is regulated by GATA4 itself. Thus, Gata4 transcription in the gonads and other tissues is ensured by distinct promoters that are regulated differentially and independently.
ISSN: 0006-3363

hal-01010626
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01010626
DOI : 10.1095/biolreprod.113.113290
PUBMED : 24352556

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Hepatocellular carcinoma treatment by arterial infusion of cis-diamminedichloroplatinum-II (cisplatin) exhibits certain therapeutic efficacy. However, optimizations are required and the mechanisms underlying cisplatin proapoptotic effect remain unclear. The mitogen-activated protein kinase (MAPK) pathway plays a key role in cell response to cisplatin and the functional specificity of the isoform MAPK/ERK kinase 1 and 2 (MEK1/2) and ERK1/2 could influence this response. The individual contribution of each kinase on cisplatin-induced death was thus analyzed after a transient or stable specific inhibition by RNA interference in the human hepatocellular carcinoma cells Huh-7 or in knockout mice. We demonstrated here that ERK1 played a predominant role over ERK2 in cisplatin-induced death, whereas MEK1 and MEK2 acted in a redundant manner. Indeed, at clinically relevant concentrations of cisplatin, ERK1 silencing alone was sufficient to protect cells from cisplatin-induced death both in vitro, in Huh-7 cells and ERK1(-/-) hepatocytes, and in vivo, in ERK1-deficient mice. Moreover, we showed that ERK1 activity correlated with the induction level of the proapoptotic BH3-only protein Noxa, a critical mediator of cisplatin toxicity. On the contrary, ERK2 inhibition upregulated ERK1 activity, favored Noxa induction and sensitized hepatocarcinoma cells to cisplatin. Our results point to a crucial role of ERK1 in cisplatin-induced proapoptotic signal and lead us to propose that ERK2-specific targeting could improve the efficacy of cisplatin therapy by increasing ERK1 prodeath functions.
ISSN: 0143-3334

inserm-00814096
http://www.hal.inserm.fr/inserm-00814096
DOI : 10.1093/carcin/bgs317
PUBMED : 23042098

Éditeur(s) : HAL CCSD American Society for Cell Biology
Résumé : International audience
Based on its shedding and binding activities, the disintegrin and metalloprotease 12 (ADAM12) has been implicated in cell signaling. Here we investigate the intracellular protein interaction network of the transmembrane ADAM12L variant using an integrative approach. We identify the integrin-linked kinase (ILK) as a new partner for ADAM12L cellular functions. We demonstrate that ADAM12L coimmunoprecipitates with ILK in cells and that its cytoplasmic tail is required for this interaction. In human cultured hepatic stellate cells (HSCs), which express high levels of endogenous ADAM12L and ILK, the two proteins are redistributed to focal adhesions upon stimulation of a β1 integrin-dependent pathway. We show that down-regulation of ADAM12L in HSCs leads to cytoskeletal disorganization and loss of adhesion. Conversely, up-regulation of ADAM12L induces the Akt Ser-473 phosphorylation-dependent survival pathway via stimulation of β1 integrins and activation of phosphoinositide 3-kinase (PI3K). Depletion of ILK inhibits this effect, which is independent of ADAM12L proteolytic activity and involves its cytoplasmic domain. We further demonstrate that overexpression of ADAM12L promotes kinase activity from ILK immunoprecipitates. Our data suggest a new role for ADAM12L in mediating the functional association of ILK with β1 integrin to regulate cell adhesion/survival through a PI3K/Akt signaling pathway.
ISSN: 1059-1524

Droits : info:eu-repo/semantics/OpenAccess
inserm-00717429
http://www.hal.inserm.fr/inserm-00717429
http://www.hal.inserm.fr/inserm-00717429/document
http://www.hal.inserm.fr/inserm-00717429/file/MBoC_E11-11-0918R-A_LEYME_ET_AL.pdf
PUBMED : 22767580

Éditeur(s) : HAL CCSD Cold Spring Harbor Laboratory Press
Résumé : International audience
Meiotic recombination is required for the segregation of homologous chromosomes and is essential for fertility. In most mammals, the DNA double-strand breaks (DSBs) that initiate meiotic recombination are directed to a subset of genomic loci (hot spots) by sequence-specific binding of the PRDM9 protein. Rapid evolution of the DNA-binding specificity of PRDM9 and gradual erosion of PRDM9-binding sites by gene conversion will alter the recombination landscape over time. To better understand the evolutionary turnover of recombination hot spots and its consequences, we mapped DSB hot spots in four major subspecies of Mus musculus with different Prdm9 alleles and in their F1 hybrids. We found that hot spot erosion governs the preferential usage of some Prdm9 alleles over others in hybrid mice and increases sequence diversity specifically at hot spots that become active in the hybrids. As crossovers are disfavored at such hot spots, we propose that sequence divergence generated by hot spot turnover may create an impediment for recombination in hybrids, potentially leading to reduced fertility and, eventually, speciation
ISSN: 0890-9369

hal-01281480
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01281480
DOI : 10.1101/gad.270009.115
PUBMED : 26833728

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
Background : Trichoderma reesei is the main industrial source of cellulases and hemicellulases required for the hydrolysis of biomass to simple sugars, which can then be used in the production of biofuels and biorefineries. The highly productive strains in use today were generated by classical mutagenesis. As byproducts of this procedure, mutants were generated that turned out to be unable to produce cellulases. In order to identify the mutations responsible for this inability, we sequenced the genome of one of these strains, QM9136, and compared it to that of its progenitor T. reesei QM6a.Results : In QM9136, we detected a surprisingly low number of mutagenic events in the promoter and coding regions of genes, i.e. only eight indels and six single nucleotide variants. One of these indels led to a frame-shift in the Zn2Cys6 transcription factor XYR1, the general regulator of cellulase and xylanase expression, and resulted in its C-terminal truncation by 140 amino acids. Retransformation of strain QM9136 with the wild-type xyr1 allele fully recovered the ability to produce cellulases, and is thus the reason for the cellulase-negative phenotype. Introduction of an engineered xyr1 allele containing the truncating point mutation into the moderate producer T. reesei QM9414 rendered this strain also cellulase-negative. The correspondingly truncated XYR1 protein was still able to enter the nucleus, but failed to be expressed over the basal constitutive level.Conclusion : The missing 140 C-terminal amino acids of XYR1 are therefore responsible for its previously observed auto-regulation which is essential for cellulases to be expressed. Our data present a working example of the use of genome sequencing leading to a functional explanation of the QM9136 cellulase-negative phenotype.
ISSN: 1471-2164

Droits : http://creativecommons.org/licenses/by/
hal-01149671
http://hal.upmc.fr/hal-01149671
http://hal.upmc.fr/hal-01149671/document
http://hal.upmc.fr/hal-01149671/file/Lichius_2015_Genome_sequencing.pdf
DOI : 10.1186/s12864-015-1526-0

Éditeur(s) : HAL CCSD
Résumé : The spectrin-based skeleton is an essential scaffold underlying different lipid bilayers in all animal cells. Spectrins (Sp), as giant extended flexible heterotetramers (αβ)2, constitute the filaments of this network, the nodes of which are cross-linked by actin filaments. The functions of the Sp-based skeleton, which are well defined in red blood cells (required for shape, resistance to shear stress and deformability) are less well understood in non-erythroid cells.The non-erythroid Sp might participate in the establishment and/or the maintenance of specialized membrane subdomains by accumulating integral membrane proteins (such as ionic channels, ionic pumps, receptors and cell adhesion molecules) as revealed by loss of the main non-erythroid β-Sp. However the effect of non-erythroid α-Sp are less well established. In mammals, α-Sp are encoded by two genes: one for αI-Sp mainly expressed in mature erythrocyte, the second one for αII-Sp which is expressed in all nucleated cells.In the pursuit of αII-Sp functions, we have checked the effect of αII-Sp knock down by siRNA melanoma human cell line. Our data revealed that spectrin depletion is associated with i) an arrest of cell cycle at G1 state ii) a loss of cell adhesion in spite of increase in some integrins iii) some modifications of actin organisation.
Le squelette dépendant de la spectrine, localisé sous la bicouche lipidique, est un échafaudage essentiel de toutes les cellules animales. La Spectrine (Sp), structure géante, robuste mais flexible d'hétéro tétramères (αβ)2, constitue les filaments de ce réseau, dont chaque nœud interagit avec des filaments d'actine. Les fonctions du squelette de Sp, qui sont bien définies dans le globule rouge (rôle dans sa forme, dans sa résistance aux forces de cisaillement et dans sa déformabilité) sont moins bien connues dans les cellules non-érythroïdes. La Sp non-érythroïde pourrait participer à l'établissement et/ou au maintien de sous-domaines membranaires spécialisés dans l'accumulation de protéines de membrane (telles que les canaux ioniques, les pompes ioniques, les récepteurs et les molécules d'adhérence) comme nous le font penser les invalidations de la Sp-β non-érythroïde. Cependant le rôle de la Sp-α non-érythroïde est moins bien établi. Chez les mammifères, la Sp-α est codée par deux gènes: un pour Sp-αI, principalement exprimée dans l'érythrocyte mature, le second pour Sp-αII qui est exprimée dans toutes les cellules nucléées. Pour étudier les fonctions de la Sp-αII, nous avons utilisé une approche de SiRNA sur des cellules de mélanome humain. Nos données montrent que la diminution de Sp-αII est associée à I) un arrêt en G1 du cycle cellulaire II) une perte d'adhérence des cellules malgré l'augmentation de quelques intégrines III) des modifications dans l'organisation du réseau d'actine.
https://tel.archives-ouvertes.fr/tel-00377569

Droits : info:eu-repo/semantics/OpenAccess
tel-00377569
https://tel.archives-ouvertes.fr/tel-00377569
https://tel.archives-ouvertes.fr/tel-00377569/document
https://tel.archives-ouvertes.fr/tel-00377569/file/these_210409_entiere.pdf
https://tel.archives-ouvertes.fr/tel-00377569/file/II-Spectrin_Is_Critical_for_Cell_Adhesion_and_Cell_Cycle.PDF

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Polycyclic aromatic hydrocarbons (PAHs) such as benzo(a)pyrene (BaP) are widely-distributed environmental contaminants known to exert toxic effects in various tissues, including placenta. PAHs have notably been shown to inhibit proliferation of trophoblastic cells. The present study was designed to determine whether PAHs can concomitantly affect differentiated functions of trophoblastic cells. BaP was found to induce expression and secretion of β-human chorionic gonadotropin (β-hCG) in human trophoblastic BeWo cells. The PAH also increased mRNA expressions of other trophoblastic differentiation markers, including those of the steroid metabolism enzymes CYP19A1 and HSD11B2 and of the fusogenic protein syncytin-2; in parallel, it triggered syncytialisation of BeWo cells. BaP-mediated β-hCG and syncytin-2 up-regulation was prevented by co-treatment by the aryl hydrocarbon receptor (AhR) antagonist CH-223191 or by knocking-down AhR expression through siRNA transfection. However, the potent AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) failed to induce expression of β-hCG and syncytin-2, indicating that activation of the AhR pathway, known to be implicated in most, if not all, effects of PAHs, was required, but not sufficient. Interestingly, the p53 signaling pathway was activated by BaP, but not by TCDD, in BeWo cells and co-treatment by the p53 inhibitor pifithrin-α or siRNAs-mediated silencing of p53 prevented up-regulation of β-hCG and syncytin-2 induced by BaP. Taken together, these data demonstrate that BaP induces differentiation of placental trophoblastic BeWo cells in an AhR- and p53-dependent manner.
ISSN: 0009-2797

hal-00982355
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00982355
DOI : 10.1016/j.cbi.2013.12.004
PUBMED : 24361490

Éditeur(s) : HAL CCSD Taylor & Francis
Résumé : International audience
INTRODUCTION: The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor historically known for regulating expression of several important drug-detoxifying proteins. Besides drug metabolism pathways, cytokines have been recently recognized as targeted by the AhR signaling cascade, which may contribute to toxicity and changes in xenobiotic detoxification caused by AhR agonists. AREAS COVERED: This article summarizes the nature of the main cytokines regulated by AhR ligands and reviews their involvement in toxic effects of AhR ligands, especially in relation with inflammation. The article also discusses the potential implications for drug detoxification pathways. EXPERT OPINION: Even if various cytokines, including inflammatory ones, have already been demonstrated to constitute robust targets for AhR, the exact role played by AhR with respect to inflammation remains to be determined. Further studies are also required to better characterize the molecular mechanisms implicated in regulation of cytokines by AhR ligands and to determine the role that may play AhR-targeted cytokines in alteration of xenobiotic detoxification. Finally, changes in cytokine receptor expression triggered by AhR ligands have additionally to be taken into account to better and more extensively comprehend the role played by AhR in the cytokine/inflammation area.
ISSN: 1742-5255

inserm-00831662
http://www.hal.inserm.fr/inserm-00831662
DOI : 10.1517/17425255.2013.738194
PUBMED : 23230817

Éditeur(s) : HAL CCSD EDP Sciences
Résumé : No matter which production system is considered (5% milk farms, 95% meatfarms), the Salers breed of cattle carries a strong image. Our work aims at showing that the development of the main territory in which the breed is found may rely on specific and identified products afforded by the breed. Multidisciplinary research (animal science, economics, food quality) and different methods (surveys, follow-up, and experimentation) were implemented. The experiments focused on the control of various types of production (milk, carcasses) and on a detailed description of the products (meat, cheese), given the attributes and the special behaviour of the animals. A before-weaning feeding approach favouring milk and forage later proves more efficient for finishing the young Salers male (15 months). The meat from these young bulls is clear, classified as mid-range quality, and can be sold in supermarkets. Parallel observations were made on farms and specific protein markers of juiciness were identified. Milk from Salers cows differs from that of Holstein especially in the nature of the fatty acids. Calf suckling before milking reinforces the differences. Cheeses made with raw milk from the breed differ in their textures and flavours. The cow must however be milked with her calf and the level of labour required impedes economic valorisation of the breed. Consumer surveys have confirmed the strong image of the breed that has a good potential for commercial development. Willingness to pay for identified products, however, is stronger for cheese (up to 30%) than for meat (up to 10%). Recognized qualities of products identified as issued from Salers cattle and originality in production systems can bring significant gains to various local actors, which can be considered as territorial rents.
La race bovine Salers bénéficie d’une image forte et reconnue, indépendante du système de production, laitier pour 5 % des élevages, ou allaitant pour 95 %. Pour autant le développement du « berceau de la race » peut-il s’appuyer sur les combinaisons de productions spécifiques et identifiées qu’autorise cette race ? Des recherches multidisciplinaires (zootechnie, économie, qualité des aliments) et des méthodes d’investigation variées (enquêtes, suivis, expérimentation) ont été mises en œuvre pour répondre à cette question. Les expérimentations ont porté sur la maîtrise des itinéraires de production (lait, carcasses) et la connaissance fine des produits (fromages, viandes), compte tenu des aptitudes et du comportement de la race. Une conduite alimentaire privilégiant le lait et les fourrages avant sevrage est ainsi plus efficace pour la production d’un jeune bovin Salers (15 mois). La viande de ces taurillons est claire, classée en gamme intermédiaire, mais peut se valoriser en grande et moyenne distribution. Le lait des vaches Salers diffère de celui des vaches Holstein surtout par la nature de ses acides gras. La tétée d’amorçage du veau spécifique de la race et difficile à supprimer, renforce les différences de composition. Les fromages fabriqués avec ce lait traité à l’état cru diffèrent par leurs textures et arômes. Une filière laitière pérenne pourrait bien valoriser ces différences mais la pénibilité de la traite faite obligatoirement en présence du veau reste un obstacle. Des enquêtes auprès de consommateurs ont confirmé la forte image de la race vectrice de valorisation économique. Leur consentement à payer pour des produits identifiés est cependant plus fort pour le fromage (jusqu’à 30 %) que pour la viande (jusqu’à 10 %). Les qualités reconnues des produits identifiés comme issus de vaches Salers et l’originalité des systèmes de production peuvent apporter des plus-values significatives aux divers acteurs locaux, ce qui peut correspondre à une forme de rente territoriale.
ISSN: 1166-7699

hal-00992549
https://hal.archives-ouvertes.fr/hal-00992549
DOI : 10.1684/agr.2014.0687
PRODINRA : 259206