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P Chardon

Publications and source records attributed to P Chardon.

At least 37 records · Page 2Linked to original sources
PubMed2000

A mutation in PRKAG3 associated with excess glycogen content in pig skeletal muscle.

A high proportion of purebred Hampshire pigs carries the dominant RN- mutation, which causes high glycogen content in skeletal muscle. The mutation has beneficial effects on meat content but detrimental effects on processing yield. Here, it is shown that the mutation is a nonconservative substitution (R200Q) in the PRKAG3 gene, which encodes a muscle-specific isoform of the regulatory gamma subunit of adenosine monophosphate-activated protein kinase (AMPK). Loss-of-function mutations in the homologous gene in yeast (SNF4) cause defects in glucose metabolism, including glycogen storage. Further analysis of the PRKAG3 signaling pathway may provide insights into muscle physiology as well as the pathogenesis of noninsulin-dependent diabetes mellitus in humans, a metabolic disorder associated with impaired glycogen synthesis.

AMP-Activated Protein Kinases↗
PubMed2000

Evolution of the neuropeptide Y receptor family: gene and chromosome duplications deduced from the cloning and mapping of the five receptor subtype genes in pig.

Neuropeptide Y (NPY) receptors mediate a variety of physiological responses including feeding and vasoconstriction. To investigate the evolutionary events that have generated this receptor family, we have sequenced and determined the chromosomal localizations of all five presently known mammalian NPY receptor subtype genes in the domestic pig, Sus scrofa (SSC). The orthologs of the Y(1) and Y(2) subtypes display high amino acid sequence identities between pig, human, and mouse (92%-94%), whereas the Y(4), Y(5), and y(6) subtypes display lower identities (76%-87%). The lower identity of Y(5) is due to high sequence divergence in the large third intracellular loop. The NPY1R, NPY2R, and NPY5R receptor genes were localized to SSC8, the NPY4R to SSC14, and NPY6R to SSC2. Our comparisons strongly suggest that the tight cluster of NPY1R, NPY2R, and NPY5R on human chromosome 4 (HSA4) represents the ancestral configuration, whereas the porcine cluster has been split by two inversions on SSC8. These 3 genes, along with adjacent genes from 14 other gene families, form a cluster on HSA4 with extensive similarities to a cluster on HSA5, where NPY6R and >13 other paralogs reside, as well as another large cluster on HSA10 that includes NPY4R. Thus, these gene families have expanded through large-scale duplications. The sequence comparisons show that the NPY receptor triplet NPY1R-NPY2R-NPY5R existed before these large-scale duplications.

Animals↗
PubMed1999

Spatial arrangement of pig MHC class I sequences.

Bacterial artificial chromosome (BAC) clones were assigned within the pig major histocompatibility complex (Mhc) by polymerase chain reaction-screening and Southern blot hybridization using sequence-tagged site (STS) markers and BAC end-rescued sequences. In all, 35 BAC clones were discovered containing 12 anchor genes of the SLA class I region and two genes of the SLA class III region. Twenty of these 35 clones comprised two distinct class I gene clusters, each spanning about 100 kilobases. One cluster enclosed three class I related genes (SLA-6 to -8) and two genes (MIC-1 and MIC-2) more distantly related to class I. The other cluster enclosed typical class I genes, of which three (SLA-1, -2, and -3) were transcribed by fibroblasts homozygous for the H01 haplotype which we used to construct a pig BAC library. Ordered clones are certainly helpful in isolating agronomically, biologically, and medically important genes. They would also be useful for inducing genetic modifications in pig cell lines.

Animals↗
PubMed1999

Characterization of 18 new BoLA-DRB3 alleles.

The second exon of the bovine MHC class II DRB3 gene was amplified by polymerase chain reaction (PCR) from DNA samples of 568 zebu Brahman cattle (Bos indicus) from Martinique (French West Indies). Cloning of these PCR products allowed the isolation of both alleles from each animal, which were characterized by the PCR-restriction fragment length polymorphism (RFLP) technique using the restriction enzymes RsaI, BstYI and HaeIII. Four new PCR-RFLP patterns were obtained by digestion with RsaI. These patterns were named 'v', 'w', 'x' and 'y' continuing the accepted nomenclature. Sequencing of each allele allowed the identification of 18 new BoLA-DRB3 exon 2 nucleotide sequences and their deduced amino acid sequences.

Alleles↗
PubMed1999

Physical assignments of human chromosome 13 genes on pig chromosome 11 demonstrate extensive synteny and gene order conservation between pig and human.

Previous mapping between the human and pig genomes suggested extensive conservation of human chromosome 13 (HSA13) to pig chromosome 11 (SSC11). The objectives of this study were comparative gene mapping of pig homologs of HSA13 genes and examining gene order within this conserved synteny group by physical assignment of each locus. A detailed HSA13 to SSC11 comparison was chosen since the comparative gene map is not well developed for these chromosomes and a rearranged gene order within conserved synteny groups was observed from the comparison between HSA13 and bovine chromosome 12 (BTA12). Heterologous primers for PCR were designed and used to amplify pig homologous fragments. The pig fragments were sequenced to confirm the homology. Six pig STSs (FLT1, ESD, RB1, HTR2A, EDNRB, and F10) were physically mapped using a somatic cell hybrid panel to SSC11, and fluorescent in situ hybridization (FISH) mapping was also applied to improve map resolution and determine gene order. Results from this study increase the comparative information available on SSC11 and suggest a conserved gene order on SSC11 and HSA13, in contrast to human:bovine comparisons of this syntenic group.

Animals↗
PubMed1999

The major histocompatibility complex in swine.

In swine, the major histocompatibility complex (Mhc) or swine leukocyte antigen (SLA) is located on chromosome 7 and divided by the centromere. Thus, the telomeric class I and more centromeric class III regions are located on the p arm and the class II region is located on the q arm. The SLA region spans about 2 Mb, in which more than 70 genes have so far been characterized. Despite its division by the centromere, the spatial relationships between the genes in the class II and class III regions, and between the well-conserved non-class I genes of the class I region, are similar to those found in the human HLA complex. On the other hand, no orthologous relationships have been found between the Mhc class I genes in man and swine. In swine, the 12 SLA class I sequences constitute two distinct clusters. One cluster comprises six classical class I-related sequences, while the other comprises five class I-distantly related sequences including two swine homologous genes of the HLA Mhc class I chain-related gene (MIC) sequence family. The number of functional SLA classical class I genes, as defined by serology, probably varies from one to four, depending on the haplotype. Some of the SLA class I-distantly related sequences are clearly transcribed. As regards the SLA class II genes, some of them clearly code for at least one functional SLA-DR and one SLA-DQ heterodimer product, but none code for any DP product. The amino acid alignment of the variable domains of 33 SLA classical class I chains, and 62 DR beta and 20 DQ beta chains confirmed the exceptionally polymorphic pattern of these polypeptides. Among the class II genes, the genes are either monomorphic, like the DRA gene, or oligomorphic, like the DQA genes. In contrast, the DRB and DQB genes display considerable polymorphism, which seems more marked in DRB than DQB genes.

Amino Acid Sequence↗
PubMed1999

Construction of a swine BAC library: application to the characterization and mapping of porcine type C endoviral elements.

A porcine bacterial artificial chromosome (BAC) library was constructed using the pBeloBAC11 vector. It comprised 107,520 clones with an average insert size of 135 kb, representing an almost fivefold coverage of the swine haploid genome. Screening of the library allowed recovery of one to eight clones for 142 unique markers located all over the genome, while it failed for only one marker. About 4% chimeric clones were found. The library was also screened for the protease gene of type C porcine endoviral sequences (PERVs), and 62 clones were recovered, all but two of which contained one protease gene. We found 20 protease sequences (PERV-1 to PERV-20) which, despite differing by point mutations, were all coding sequences. The most frequent sequence, PERV-2, was 100% similar to a protease sequence expressed in the porcine PK-15 cell line. Most of the clones harbored envelope genes. Thirty-three BAC clones were mapped by fluorescence in situ hybridization to 22 distinct locations on 14 chromosomes, including the X and Y chromosomes. These overall results indicate that there is generally one PERV copy per integration site. Although PERV sequences were not tandemly arranged, clusters of integration sites were observed at positions 3p1.5 and 7p1.1. Southern blot experiments revealed 20-30 PERV copies in the Large White pig genome studied here, and variations in PERV content among pigs of different breeds were observed. In conclusion, this BAC collection represents a significant contribution to the swine large genomic DNA cloned insert resources and provides the first detailed map of PERV sequences in the swine genome. This work is the first step toward identification of potential active sites of PERV elements.

Amino Acid Sequence↗
PubMed1999

Human chromosome 3 and pig chromosome 13 show complete synteny conservation but extensive gene-order differences.

A comparative map of human chromosome 3 (HSA 3) and pig chromosome 13 (SSC 13) was constructed using physically assigned pig sequence-tagged sites (STSs). Pig STSs representing 11 HSA 3 genes, including v-Raf-1 murine leukemia viral oncogene homolog 1 (RAF1), retinoic acid beta receptor (RARB), cholecystokinin (CCK), pituitary transcription factor 1 (POU1F1), ceruloplasmin (CP), guanine nucleotide binding protein, alpha-inhibiting polypeptide 2 (GNAI2), sucrase-isomaltase (SI), rhodopsin (RHO), dopamine receptor D3 (DRD3), growth-associated protein 43 (GAP43), and somatostatin (SST), were developed. Ten pig STSs were regionally mapped using a somatic cell hybrid panel (SCHP) to SSC 13 with 80-100% concordance. Large-insert probes were obtained by screening a pig yeast artificial chromosome (YAC) library with primers for each STS. Several YACs were identified for DRD3, GAP43, POU1F1, RHO, SI, and SST for fluorescence in situ hybridization (FISH) mapping. Single gene and bi-color FISH with each pairwise combination were used to further define the gene order on SSC 13. While these data confirm chromosome painting results showing that HSA 3 probes hybridize to a major portion of SSC 13, they also demonstrate extensive gene-order differences between man and pig within this large conserved synteny group. Interestingly, several conserved chromosomal regions have been detected between pig and mouse that are not conserved between man and mouse, suggesting that the SSC 13 gene arrangement may be the closest to that of the ancestral eutherian chromosome.

Animals↗
PubMed1998

Melanocortin receptor 1 (MC1R) mutations and coat color in pigs.

The melanocortin receptor 1 (MC1R) plays a central role in regulation of eumelanin (black/brown) and phaeomelanin (red/yellow) synthesis within the mammalian melanocyte and is encoded by the classical Extension (E) coat color locus. Sequence analysis of MC1R from seven porcine breeds revealed a total of four allelic variants corresponding to five different E alleles. The European wild boar possessed a unique MC1R allele that we believe is required for the expression of a wild-type coat color. Two different MC1R alleles were associated with the dominant black color in pigs. MC1R*2 was found in European Large Black and Chinese Meishan pigs and exhibited two missense mutations compared with the wild-type sequence. Comparative data strongly suggest that one of these, L99P, may form a constitutively active receptor. MC1R*3 was associated with the black color in the Hampshire breed and involved a single missense mutation D121N. This same MC1R variant was also associated with EP, which results in black spots on a white or red background. Two different missense mutations were identified in recessive red (e/e) animals. One of these, A240T, occurs at a highly conserved position, making it a strong candidate for disruption of receptor function.

Alleles↗
PubMed1998

A first map of the porcine major histocompatibility complex class I region.

A map of the SLA complex, or swine major histocompatibility complex (MHC), class I region was constructed by alignment of yeast artificial chromosomes (YACs) harboring MHC class I genes as well as anchor genes already mapped within the human MHC complex (HLA). Five YACs containing 9 anchor genes built a contig of about 1.0-1.2 Mb between the SLA class III BAT1 locus and the olfactory receptor-like genes OLF42. Ten different SLA class I sequences, including putative allelic forms of published classical and non-classical SLA class I genes, were assigned to the 400-kb enclosing centromeric part of the contig. Three additional YACs comprising the OLF89 genes and two YACs containing the butyrophilin gene were located telomeric to the contig. Comparison between the human and porcine MHC complexes showed a perfect conserved order of anchor genes, whereas no orthologous relationships were found for the class I loci.

Animals↗