Publications by authors named "Sandrine Freret"

7 Publications

  • Page 1 of 1

Identification of new antigen candidates for the early diagnosis of Mycobacterium avium subsp. paratuberculosis infection in goats.

Res Vet Sci 2017 Dec 26;115:278-287. Epub 2017 May 26.

ISP, INRA, 37380 Nouzilly, France. Electronic address:

Currently Mycobacterium avium subsp. paratuberculosis (MAP) infection is diagnosed through indirect tests based on the immune response induced by the infection. The antigens commonly used in IFN-γ release assays (IGRA) are purified protein derivative tuberculins (PPD). However, PPDs, lack both specificity (Sp) and sensitivity (Se) in the early phase of infection. This study investigated the potential of 16 MAP recombinant proteins and five lipids to elicit the release of IFN-γ in goats from herds with or without a history of paratuberculosis. Ten recombinant proteins were selected as potential candidates for the detection of MAP infection in young goats. They were found to detect 25 to 75% of infected shedder (IS) and infected non-shedder (INS) kids younger than 10months of age. In comparison, PPD was shown to detect only 10% of INS and no IS kids. For seven antigens, Se (21-33%) and Sp (≥90%) of IGRA were shown to be comparable with PPD at 20months old. Only three antigens were suitable candidates to detect IS adult goats, although Se was lower than that obtained with PPD. In paratuberculosis-free herds, IGRA results were negative in 97% of indoor goats and 86% of outdoor goats using the 10 antigens. However, 22 to 44% of one-year-old outdoor goats were positive suggesting that they may be infected. In conclusion, this study showed that ten MAP recombinant proteins are potential candidates for early detection of MAP infected goats. Combining these antigens could form a possible set of MAP antigens to optimize the Se of caprine IGRA.
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http://dx.doi.org/10.1016/j.rvsc.2017.05.025DOI Listing
December 2017

A longitudinal study of the Mycobacterium avium subspecies paratuberculosis infection status in young goats and their mothers.

Vet Microbiol 2016 Nov 27;195:9-16. Epub 2016 Aug 27.

UR1282 Infectiologie et Santé Publique, INRA Centre Val de Loire, 37380 Nouzilly, France. Electronic address:

The dynamics between Mycobacterium avium subspecies paratuberculosis (MAP) infection and the immune response of goats naturally exposed to MAP were studied in a herd where the clinical expression of paratuberculosis had been observed. Four generations of goats were observed over a 33-month period: mothers of three different generations (G1, G2, G3) and their daughters, generation 4 (G4). A MAP infection status was defined according to the combined results of an IFN-γ assay, antibody response, faecal culture and post-mortem examination. Goats were defined as non-infected (NI), infected and non-shedder (INS), infected and shedder (IS) or atypical (A). Twenty-nine percent of goats were NI, 66% were infected and either shedding (14%) or not shedding (52%) MAP, and 5% were atypical. IFN-γ responses were detected first, followed by faecal shedding and antibody responses. The results showed that in goats naturally exposed to MAP, IFN-γ responses were regularly detected earlier in non-shedders than in young infected shedder goats and were stronger in shedder than in non-shedder goats. They were also higher in the mother goats than in their daughters. Goats shedding MAP or with positive antibody response at the beginning of their pregnancy are more likely to have an infected daughter positive to an IFN-γ assay by the age of 15 months.
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http://dx.doi.org/10.1016/j.vetmic.2016.08.021DOI Listing
November 2016

Effect of a long-chain n-3 polyunsaturated fatty acid-enriched diet on adipose tissue lipid profiles and gene expression in Holstein dairy cows.

J Dairy Sci 2016 Dec 28;99(12):10109-10127. Epub 2016 Sep 28.

UMR PRC, CNRS, IFCE, INRA, Université de Tours, 37380, Nouzilly, France.

The objective of this study was to determine whether fish oil supplement has an effect on adipose tissue lipid profiles and gene expression in postpartum dairy cows. Holstein cows were supplemented with either long-chain n-3 polyunsaturated fatty acid (PUFA; protected fish oil) or control PUFA (n-6; toasted soybeans) for 2mo after calving (n=23 per diet). These cows showed no difference in milk production or metabolic parameters, but exhibited a tendency toward a decrease in early embryo mortality rate after artificial insemination. We hypothesized that, in addition to this effect, modifications in adipose tissue (AT) gene expression and lipid profiles would occur in response to diet. Subcutaneous AT samples were thus collected from the dewlaps of n-3 and n-6 dairy cows at 1mo antepartum, and 1wk, 2mo, and 5mo postpartum for the analysis of lipids and gene expression. Lipid profiles were obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in both positive and negative modes. We found 37 lipid species in the 200 to 1,200 m/z range, which differed between the n-3 and control groups, suggesting that the n-3 supplement affected the lipid composition through the enrichment of lipids integrating long-chain PUFA from fish oil sources: eicosapentaenoic and docosahexaenoic acid. Moreover, a decrease in triacylglycerolipids was observed in AT of n-3 supplemented cows. The expression of 44 genes involved in fatty acid metabolism and the adipokine system was assessed by real-time reverse-transcription PCR. Hierarchical clustering, according to either postpartum stage or diet, enabled us to group genes exhibiting similar kinetic properties during lactation or by those that varied in similar ways after n-3 supplementation, respectively. Among the genes exhibiting a dietary effect, FABP4, LIPE, CD36, and PLIN1 were overexpressed in n-3 AT samples compared with the control, suggesting an increase in lipolysis due to n-3 supplementation, which was reflected on lipolytic activity at the protein level (i.e., protein expression of fatty acid binding protein 4, phosphorylated perilipin 1, and phosphorylated hormone-sensitive lipase). This increase in lipolysis is relevant to the decrease in triglycerides observed in these samples. Gene expression analyses between n-3 and control AT samples also suggested that the n-3 diet could modulate the secretory functions of AT, possibly by affecting adipokine expression; however, this has to be confirmed at the protein level.
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http://dx.doi.org/10.3168/jds.2016-11052DOI Listing
December 2016

Effect of a long chain n-3 PUFA-enriched diet on production and reproduction variables in Holstein dairy cows.

Anim Reprod Sci 2016 Jan 23;164:121-32. Epub 2015 Nov 23.

INRA, UMR85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France; CNRS, UMR 7247 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France; Université François Rabelais de Tours, UMR Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France; IFCE, UMR Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France.

The objective of this study was to determine the effect of a rumen-protected fish oil supplement on the production and reproduction variables in postpartum dairy cows. Holstein cows (n=46) were given a basal total mixed diet plus one PUFA supplement: n-3 (n-3; protected fish oil; 1% dry matter intake (DMI); n=23) or control (n-6; toasted soybeans; 1.8% DMI; n=23), in a switchback design over two consecutive lactations. Supplements were added to the diet between calving and 2 months after calving to assess the effect on growth and maturation of ovarian follicles from which ovulation occurred around the day of insemination. Body weight (BW), milk yield (MY) and composition, dry matter intake (DMI), energy balance (EB), subcutaneous fat thickness, plasma fatty acid composition, plasma nonesterified fatty acids (NEFA), glucose and urea concentrations, follicular activity, embryo mortalities and fertility (conception rate after first AI, AI1) were assessed. BW, MY, DMI, plasma NEFA, glucose and urea were unaffected by the diet. There was a trend of an increased number of large follicles (diameter≥10mm) with the n-3 dietary supplementation (P=0.06) and a decrease in infertility or early embryo mortality rate 21 days after AI, 13.5% in the n-3 compared with 38.8% in the n-6 group (P=0.09), with no effect on the conception rate at 35d or 90d after AI1. These data suggest that the effect seen on ovarian variables is not associated with an effect on production and metabolic variables and is specific to n-3 PUFA supplementation. Further studies are necessary to determine whether DHA or EPA enhances fertility in lactating dairy cattle.
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http://dx.doi.org/10.1016/j.anireprosci.2015.11.020DOI Listing
January 2016

Progesterone improves the maturation of male-induced preovulatory follicles in anoestrous ewes.

Reproduction 2014 Oct 25;148(4):403-16. Epub 2014 Jul 25.

Institut National de la Recherche AgronomiqueUMR85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, FranceCentre National de la Recherche ScientifiqueUMR 7247, F-37380 Nouzilly, FranceUniversité François Rabelais de ToursF-37041 Tours, France andInstitut Français du Cheval et de l'EquitationF-37380 Nouzilly, France Institut National de la Recherche AgronomiqueUMR85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, FranceCentre National de la Recherche ScientifiqueUMR 7247, F-37380 Nouzilly, FranceUniversité François Rabelais de ToursF-37041 Tours, France andInstitut Français du Cheval et de l'EquitationF-37380 Nouzilly, France Institut National de la Recherche AgronomiqueUMR85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, FranceCentre National de la Recherche ScientifiqueUMR 7247, F-37380 Nouzilly, FranceUniversité François Rabelais de ToursF-37041 Tours, France andInstitut Français du Cheval et de l'EquitationF-37380 Nouzilly, France Institut National de la Recherche AgronomiqueUMR85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, FranceCentre National de la Recherche ScientifiqueUMR 7247, F-37380 Nouzilly, FranceUniversité François Rabelais de ToursF-37041 Tours, France andInstitut Français du Cheval et de l'EquitationF-37380 Nouzilly, France

The first ovulation induced by male effect in sheep during seasonal anoestrus usually results in the development of a short cycle that can be avoided by progesterone priming before ram introduction. In elucidating the involvement of the hypothalamic-pituitary-gonadal axis in the occurrence of short cycles, the effects of progesterone and the time of anoestrus on the development of male-induced preovulatory follicles were investigated in anoestrous ewes using morphological, endocrine and molecular approaches. Ewes were primed with progesterone for 2 (CIDR2) or 12 days (CIDR12) and untreated ewes used as controls during early (April) and late (June) anoestrus. The duration of follicular growth and the lifespan of the male-induced preovulatory follicles were prolonged by ∼1.6 days in CIDR12 ewes compared with the controls. These changes were accompanied by a delay in the preovulatory LH and FSH surges and ovulation. Intra-follicular oestradiol concentration and mRNA levels of LHCGR and STAR in the granulosa and theca cells of the preovulatory follicles were higher in CIDR12 ewes than the control ewes. The expression of mRNA levels of CYP11A1 and CYP17A1 also increased in theca cells of CIDR12 ewes. CIDR2 ewes gave intermediate results. Moreover, ewes ovulated earlier in June than in April, without changes in the duration of follicular growth, but these effects were unrelated to the lifespan of corpus luteum. Our results give the first evidence supporting the positive effect of progesterone priming on the completion of growth and maturation of preovulatory follicles induced by male effect in seasonal anoestrous ewes, thereby preventing short cycles.
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http://dx.doi.org/10.1530/REP-14-0263DOI Listing
October 2014

Alteration of energy metabolism gene expression in cumulus cells affects oocyte maturation via MOS-mitogen-activated protein kinase pathway in dairy cows with an unfavorable "Fertil-" haplotype of one female fertility quantitative trait locus.

Theriogenology 2014 Mar 28;81(4):599-612. Epub 2013 Nov 28.

INRA, UMR85 Physiologie de la Reproduction et des Comportements, Nouzilly, France; CNRS UMR7247, Nouzilly, France; Université François Rabelais de Tours, Tours, France; IFCE, Nouzilly, France. Electronic address:

Prim'Holstein heifers selected for the "Fertil-" homozygous haplotype of QTL-Female-Fert ility-BTA3 showed a greater rate of early pregnancy failure and slower embryo development after IVM suggesting lower oocyte quality than those selected for "Fertile+". We aimed to ascertain intrafollicular factors related to lower oocyte quality in "Fertil-" cows. Analysis of individual oocytes showed meiotic progression delay in "Fertil-" compared with "Fertil+" dairy cows after in vivo maturation and IVM (P < 0.05). Expression of several genes localized to QTL-F-Fert-BTA3 or related to meiosis and mitogen-activated protein kinase pathway was analyzed in individual metaphase-II oocytes using reverse transcription- real-time polymerase chain reaction. Energy metabolism, apoptosis, extracellular matrix, and QTL-F-Fert-BTA3 genes were analyzed in surrounding cumulus cells (CC). In vivo, a significant decrease in prostaglandin synthase PTGES1 and PTGS2 expression coupled with lower PTGS2 protein abundance in CC and reduced expression of MOS in enclosed metaphase-II oocytes from "Fertil-" cows was observed. IVM strongly deregulated gene expression in CC and in oocytes compared with in vivo; nevertheless, differential expression of several genes including PEX19, NAMPT and MOS was observed between the two haplotypes. During IVM, PTGS2 activity inhibitor NS398 (50 μM) led to lower expression of fatty acid synthase (FASN) in CC and of MOS in treated metaphase-II oocytes. Using immunofluorescence, MOS protein was localized to a midbody-like contractile ring separating the polar body from the ooplasm, suggesting a role in the terminal stage of oocyte maturation. Our results suggest that factors involved in prostaglandin synthesis and lipid metabolism in CC could impair oocyte maturation, and might be involved in the reduced fertility of "Fertil-" cows.
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http://dx.doi.org/10.1016/j.theriogenology.2013.11.013DOI Listing
March 2014

Expression of adipokine and lipid metabolism genes in adipose tissue of dairy cows differing in a female fertility quantitative trait locus.

J Dairy Sci 2013 11;96(12):7591-602. Epub 2013 Oct 11.

INRA, UMR85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France; CNRS, UMR 7247 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France; Université François Rabelais de Tours, UMR Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France; IFCE, UMR Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France. Electronic address:

We have previously characterized 2 haplotypes (Fertil+ and Fertil-) of Holstein dairy cows differing in 1 female fertility quantitative trait locus (QTL) located on chromosome 3 (QTL-Fert-F-BTA3) between positions 9.8 and 13.5 cM. This QTL is composed of 124 genes, some of them being involved in metabolism or reproduction. Primiparous Fertil+ and Fertil- cows exhibited 69 and 39% pregnancy rate at first service, respectively. A difference in plasma nonesterified fatty acid concentrations observed between both haplotypes might indicate a difference in adipose tissue mobilization. We compared adipose tissue gene expression in Fertil+ and Fertil- cows during their second lactation, at 2 physiological stages, implying either intense lipid mobilization (1 wk postpartum) or fat storage (5 mo of gestation). We investigated by reverse-transcription quantitative PCR the mRNA gene expression of 5 positional candidate genes located in the QTL-Fert-F-BTA3, as well as 18 other functional candidate genes encoding proteins involved in lipid metabolism and several adipokines. Among them, genes involved in either lipolysis or lipogenesis were chosen as controls because they were previously described in dairy cow adipose tissue. A hierarchical clustering was performed to group genes according to their expression pattern, allowing 2 clusters to be determined. Cluster 1 was composed of genes that were overexpressed during mobilization (ADIPOQ, ADIPOR2, LIPE, FABP4, PLIN1, RARRES, LEPR, and CPT1A) and cluster 2 of genes overexpressed during reconstitution of body reserves (ACACA, FASN, and SCD). Genes belonging to cluster 1 (LIPE, FABP4, PLIN1, and CPT1A) are known to be involved in lipolysis and fatty acid oxidation, and genes belonging to cluster 2 (ACACA, FASN, and SCD) are known to be involved in fatty acid synthesis. The expression of 5 genes from cluster 1 was correlated to plasma nonesterified fatty acid levels and thus to mobilization of body reserves in dairy cows (ADIPOQ, ADIPOR2, LIPE, PLIN1, and FABP4). During the mobilization stage, none of the positional candidate genes belonging to QTL-Fert-F-BTA3 (ADAR, MTX1, SHC1, SPTA1, and PAQR6) showed a difference in expression between the 2 haplotypes. Interestingly, ADIPOQ and ADIPOR2 were the only genes showing a significant mRNA overexpression in Fertil- cows at the mobilization stage. Further studies focusing on plasma adiponectin level and adipokine actions on the ovary are needed to investigate its potential role in dairy cow fertility.
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http://dx.doi.org/10.3168/jds.2013-6615DOI Listing
April 2016