Protein catabolism and high lipid metabolism associated with long-distance exercise are revealed by plasma NMR metabolomics in endurance horses.

International audienceDuring long distance endurance races, horses undergo high physiological and metabolic stresses. The adaptation processes involve the modulation of the energetic pathways in order to meet the energy demand. The aims were to evaluate the effects of long endurance exercise on the plasma metabolomic profiles and to investigate the relationships with the individual horse performances. The metabolomic profiles of the horses were analyzed using the non-dedicated methodology, NMR spectroscopy and statistical multivariate analysis. The advantage of this method is to investigate several metabolomic pathways at the same time in a single sample. The plasmas were obtained before exercise (BE) and post exercise (PE) from 69 horses competing in three endurance races at national level (130-160 km). Biochemical assays were also performed on the samples taken at PE. The proton NMR spectra were compared using the supervised orthogonal projection on latent structure method according to several factors. Among these factors, the race location was not significant whereas the effect of the race exercise (sample BE vs PE of same horse) was highly discriminating. This result was confirmed by the projection of unpaired samples (only BE or PE sample of different horses). The metabolomic profiles proved that protein, energetic and lipid metabolisms as well as glycoproteins content are highly affected by the long endurance exercise. The BE samples from finisher horses could be discriminated according to the racing speed based on their metabolomic lipid content. The PE samples could be discriminated according to the horse ranking position at the end of the race with lactate as unique correlated metabolite. As a conclusion, the metabolomic profiles of plasmas taken before and after the race provided a better understanding of the high energy demand and protein catabolism pathway that could expose the horses to metabolic disorders

C-Nap1 mutation affects centriole cohesion and is associated with a Seckel-like syndrome in cattle

Caprine-like Generalized Hypoplasia Syndrome (SHGC) is an autosomal-recessive disorder in Montbéliarde cattle. Affected animals present a wide range of clinical features that include the following: delayed development with low birth weight, hind limb muscular hypoplasia, caprine-like thin head and partial coat depigmentation. Here we show that SHGC is caused by a truncating mutation in the CEP250 gene that encodes the centrosomal protein C-Nap1. This mutation results in centrosome splitting, which neither affects centriole ultrastructure and duplication in dividing cells nor centriole function in cilium assembly and mitotic spindle organization. Loss of C-Nap1-mediated centriole cohesion leads to an altered cell migration phenotype. This discovery extends the range of loci that constitute the spectrum of autosomal primary recessive microcephaly (MCPH) and Seckel-like syndromes

LIPH Expression in Skin and Hair Follicles of Normal Coat and Rex Rabbits

Natural mutations in the LIPH gene were shown to be responsible for hair growth defects in humans and for the rex short hair phenotype in rabbits. In this species, we identified a single nucleotide deletion in LIPH (1362delA) introducing a stop codon in the C-terminal region of the protein. We investigated the expression of LIPH between normal coat and rex rabbits during critical fetal stages of hair follicle genesis, in adults and during hair follicle cycles. Transcripts were three times less expressed in both fetal and adult stages of the rex rabbits than in normal rabbits. In addition, the hair growth cycle phases affected the regulation of the transcription level in the normal and mutant phenotypes differently. LIPH mRNA and protein levels were higher in the outer root sheath (ORS) than in the inner root sheath (IRS), with a very weak signal in the IRS of rex rabbits. In vitro transfection shows that the mutant protein has a reduced lipase activity compared to the wild type form. Our results contribute to the characterization of the LIPH mode of action and confirm the crucial role of LIPH in hair production

A multi-scale analysis of bull sperm methylome revealed both species peculiarities and conserved tissue-specific

peer-reviewedBackground: Spermatozoa have a remarkable epigenome in line with their degree of specialization, their unique nature and different requirements for successful fertilization. Accordingly, perturbations in the establishment of DNA methylation patterns during male germ cell differentiation have been associated with infertility in several species.Background: Spermatozoa have a remarkable epigenResults: The quantification of DNA methylation at CCGG sites using luminometric methylation assay (LUMA) highlighted the undermethylation of bull sperm compared to the sperm of rams, stallions, mice, goats and men. Total blood cells displayed a similarly high level of methylation in bulls and rams, suggesting that undermethylation of the bovine genome was specific to sperm. Annotation of CCGG sites in different species revealed no striking bias in the distribution of genome features targeted by LUMA that could explain undermethylation of bull sperm. To map DNA methylation at a genome-wide scale, bull sperm was compared with bovine liver, fibroblasts and monocytes using reduced representation bisulfite sequencing (RRBS) and immunoprecipitation of methylated DNA followed by microarray hybridization (MeDIP-chip). These two methods exhibited differences in terms of genome coverage, and consistently, two independent sets of sequences differentially methylated in sperm and somatic cells were identified for RRBS and MeDIP-chip. Remarkably, in the two sets most of the differentially methylated sequences were hypomethylated in sperm. In agreement with previous studies in other species, the sequences that were specifically hypomethylated in bull sperm targeted processes relevant to the germline differentiation program (piRNA metabolism, meiosis, spermatogenesis) and sperm functions (cell adhesion, fertilization), as well as satellites and rDNA repeats. Conclusions: These results highlight the undermethylation of bull spermatozoa when compared with both bovine somatic cells and the sperm of other mammals, and raise questions regarding the dynamics of DNA methylation in bovine male germline. Whether sperm undermethylation has potential interactions with structural variation in the cattle genome may deserve further attention. While bull semen is widely used in artificial insemination, the literature describing DNA methylation in bull spermatozoa is still scarce. The purpose of this study was therefore to characterize the bull sperm methylome relative to both bovine somatic cells and the sperm of other mammals through a multiscale analysis

Introduction à la cartographie des génomes complexes

National audienceLes technologies mises en place dans le cadre des projets sur les génomes humain et murin ont stimulé le développement de la cartographie des espèces d’intérêt agronomique. Des cartes ont été construites pour les ruminants, le porc, le cheval et le poulet, permettant de localiser des gènes d’intérêt agronomique ou des QTL (quantitative trait loci) chez ces espèces. Ces travaux de cartographie génétique, cytogénétique et physique devraient se révéler être des outils indispensables pour le clonage positionnel de ces gènes ou QTL

Origine du polymorphisme de l'ADN

National audienceLe développement des techniques de biologie moléculaire a permis la mise en évidence d’une très importante variabilité de l’ADN tant au niveau chromosomique (remaniements) qu’au niveau nucléotidique (mutations ponctuelles). Les différentes sources de variabilité sont décrites. Les mécanismes potentiellement impliqués dans la genèse de ces polymorphismes sont passés en revue

Cartographie fine de la région du gène PIS de la chèvre

National audienceChez les Mammifères, la différenciation sexuelle résulte d’une cascade complexe dont le premier acteur est le gène SRY, porté par le chromosome Y, qui masculinise la gonade indifférenciée. Cependant, certains individus, en l’absence de SRY, présentent un développement testiculaire et une réversion du sexe. Chez la chèvre, par exemple, la réversion du sexe d’individus XX en l’absence du gène SRY ou d’autres séquences du chromosome Y est étroitement liée à l’absence de corne (mutation motte) puisqu’aucun recombinant n’a jamais été observé. Ce syndrome, nommé PIS pour Polled Intersex Syndrome, est causé par des mutations dans un ou deux gènes autosomiques que nous avons localisés dans un premier temps à proximité de deux marqueurs microsatellites d’origine bovine sur le chromosome 1 caprin. Les cartes génétique, cytogénétique et physique de la région ont ensuite été construites à l’aide, d’une part, de banques d’ADN issues de chromosome 1 trié, des bandes 1q42, 1q43 et 1q44 microdisséquées et de grands fragments (BAC) et, d’autre part, de la cartographie comparée avec les gènes ou EST (expressed sequence tags) localisés dans la région humaine homologue. Ces différentes approches ont permis de localiser le gène PIS au sein d’un contig de 1,5 Mb, dans une région de 100 kb autour d’un marqueur microsatellite

Proton 1D NMR spectra of horse plasma sampled before the race (top spectrum) and after the race (bottom spectrum).

<p>The main metabolites are labeled as follows. 1 to 5: lipid fatty acid moieties, 1: methyl; 2: methylene, 3: methylene β ester, 4: methylene α ester, 5: acyl, 6: Branched chain amino acids (valine, leucine, isoleucine), 7: lactate, 8: alanine, 9: acetate, 10: N-acetyl moieties (glycoproteins), 11: glucose, 12: urea, 13: creatine 14: phosphocholine, 15: tyrosine, 16: exchangeable proton from carboxylic moieties, 17: creatinine, 18 : citrate. (The labels of metabolites appearing in both spectra are not repeated).</p

A: Score plot of the OPLS model computed with PE samples according to their creatinine content assessed by biochemistry.

<p>Tpred represents the predictive axis and Torth, the orthogonal axis. Each dot corresponds to a spectrum, colored according to their creatininemia. B: Loading plot of the score plot predictive axis. The metabolite correlations are represented by the color scale. Positive signals correspond to metabolites which concentration increases when creatininemia increases. The buckets are labeled according to metabolite assignments of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0090730#pone-0090730-g001" target="_blank">figure 1</a>.</p