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F Galibert

Publications and source records attributed to F Galibert.

At least 19 recordsLinked to original sources
PubMed2004

Detailed four-way comparative mapping and gene order analysis of the canine ctvm locus reveals evolutionary chromosome rearrangements.

Canine tricuspid valve malformation (CTVM) maps to canine chromosome 9 (CFA9), in a region syntenic with gene-dense human chromosome 17q. To define synteny blocks, we analyzed 148 markers on CFA9 using radiation hybrid mapping and established a four-way comparative map for human, mouse, rat, and dog. We identified a large number of rearrangements, allowing us to reconstruct the evolutionary history of individual synteny blocks and large chromosomal segments. A most parsimonious rearrangement scenario for all four species reveals that human chromosome 17q differs from CFA9 and the syntenic rodent chromosomes through two macroreversals of 9.2 and 23 Mb. Compared to a recovered ancestral gene order, CFA9 has undergone 11 reversals of <3 Mb and 2 reversals of >3 Mb. Interspecies reuse of breakpoints for micro- and macrorearrangements was observed. Gene order and content of the ctvm interval are best extrapolated from murine data, showing that multispecies genome rearrangement scenarios contribute to identifying gene content in canine mapping studies.

Animals↗
PubMed2003

Chromosome aberrations in canine multicentric lymphomas detected with comparative genomic hybridisation and a panel of single locus probes.

Recurrent chromosome aberrations are frequently observed in human neoplastic cells and often correlate with other clinical and histopathological parameters of a given tumour type. The clinical presentation, histology and biology of many canine cancers closely parallels those of human malignancies. Since humans and dogs demonstrate extensive genome homology and share the same environment, it is expected that many canine cancers will also be associated with recurrent chromosome aberrations. To investigate this, we have performed molecular cytogenetic analyses on 25 cases of canine multicentric lymphoma. Comparative genomic hybridisation analysis demonstrated between one and 12 separate regions of chromosomal gain or loss within each case, involving 32 of the 38 canine autosomes. Genomic gains were almost twice as common as losses. Gain of dog chromosome (CFA) 13 was the most common aberration observed (12 of 25 cases), followed by gain of CFA 31 (eight cases) and loss of CFA 14 (five cases). Cytogenetic and histopathological data for each case are presented, and cytogenetic similarities with human non-Hodgkin's lymphoma are discussed. We have also assembled a panel of 41 canine chromosome-specific BAC probes that may be used for accurate and efficient chromosome identification in future studies of this nature.

Animals↗
PubMed2003

A canine cancer-gene microarray for CGH analysis of tumors.

As with many human cancers, canine tumors demonstrate recurrent chromosome aberrations. A detailed knowledge of such aberrations may facilitate diagnosis, prognosis and the selection of appropriate therapy. Following recent advances made in human genomics, we are developing a DNA microarray for the domestic dog, to be used in the detection and characterization of copy number changes in canine tumors. As a proof of principle, we have developed a small-scale microarray comprising 87 canine BAC clones. The array is composed of 26 clones selected from a panel of 24 canine cancer genes, representing 18 chromosomes, and an additional set of clones representing dog chromosomes 11, 13, 14 and 31. These chromosomes were shown previously to be commonly aberrant in canine multicentric malignant lymphoma. Clones representing the sex chromosomes were also included. We outline the principles of canine microarray development, and present data obtained from microarray analysis of three canine lymphoma cases previously characterized using conventional cytogenetic techniques.

Animals↗
PubMed2001

Analysis of the chromosome sequence of the legume symbiont Sinorhizobium meliloti strain 1021.

Sinorhizobium meliloti is an alpha-proteobacterium that forms agronomically important N(2)-fixing root nodules in legumes. We report here the complete sequence of the largest constituent of its genome, a 62.7% GC-rich 3,654,135-bp circular chromosome. Annotation allowed assignment of a function to 59% of the 3,341 predicted protein-coding ORFs, the rest exhibiting partial, weak, or no similarity with any known sequence. Unexpectedly, the level of reiteration within this replicon is low, with only two genes duplicated with more than 90% nucleotide sequence identity, transposon elements accounting for 2.2% of the sequence, and a few hundred short repeated palindromic motifs (RIME1, RIME2, and C) widespread over the chromosome. Three regions with a significantly lower GC content are most likely of external origin. Detailed annotation revealed that this replicon contains all housekeeping genes except two essential genes that are located on pSymB. Amino acid/peptide transport and degradation and sugar metabolism appear as two major features of the S. meliloti chromosome. The presence in this replicon of a large number of nucleotide cyclases with a peculiar structure, as well as of genes homologous to virulence determinants of animal and plant pathogens, opens perspectives in the study of this bacterium both as a free-living soil microorganism and as a plant symbiont.

Bacterial Proteins↗
PubMed2001

Nucleotide sequence and predicted functions of the entire Sinorhizobium meliloti pSymA megaplasmid.

The symbiotic nitrogen-fixing soil bacterium Sinorhizobium meliloti contains three replicons: pSymA, pSymB, and the chromosome. We report here the complete 1,354,226-nt sequence of pSymA. In addition to a large fraction of the genes known to be specifically involved in symbiosis, pSymA contains genes likely to be involved in nitrogen and carbon metabolism, transport, stress, and resistance responses, and other functions that give S. meliloti an advantage in its specialized niche.

Agrobacterium tumefaciens↗
PubMed2001

The composite genome of the legume symbiont Sinorhizobium meliloti.

The scarcity of usable nitrogen frequently limits plant growth. A tight metabolic association with rhizobial bacteria allows legumes to obtain nitrogen compounds by bacterial reduction of dinitrogen (N2) to ammonium (NH4+). We present here the annotated DNA sequence of the alpha-proteobacterium Sinorhizobium meliloti, the symbiont of alfalfa. The tripartite 6.7-megabase (Mb) genome comprises a 3.65-Mb chromosome, and 1.35-Mb pSymA and 1.68-Mb pSymB megaplasmids. Genome sequence analysis indicates that all three elements contribute, in varying degrees, to symbiosis and reveals how this genome may have emerged during evolution. The genome sequence will be useful in understanding the dynamics of interkingdom associations and of life in soil environments.

Bacterial Adhesion↗
PubMed2001

Ribosomal protein gene cluster analysis in eubacterium genomics: homology between Sinorhizobium meliloti strain 1021 and Bacillus subtilis.

The first whole genome sequence of a symbiotic soil bacterium, Sinorhizobium meliloti (formely named Rhizobium meliloti) strain 1021, is due in 2001. As an active participant in the European and North American consortium that has completed this work, our group has sequenced a region on the chromosome containing clusters rpoBC, str, S10, spc and alpha corresponding to 30 protein genes. The structural organization and function of these genes were compared with those of orthologs in another 15 complete eubacterial genomes available in databases. This study, involving the DNA and amino acid sequences as well as the organization of the whole region (gene order, cluster order, etc.), has shown that the phylogenetic tree resulting from a comparison of the amino acid sequence is rather similar to that derived from 16S rRNA sequence data. However, the tree achieved by aligning DNA sequences groups the organisms with a high GC content (>60% GC), while that based on a comparison of gene cluster orientation and organization reveals a greater level of correspondence between the alpha-proteobacteria S.meliloti and the firmicute Bacillus subtilis.

Bacillus subtilis↗
PubMed2001

Characterization of a minimal screening set of 172 microsatellite markers for genome-wide screens of the canine genome.

We have characterized a subset of 172 microsatellite markers from the canine map, termed 'Minimal Screening Set 1' (Canine MSS-1), which we propose be used for initial genome-wide genetic linkage studies. Three hierarchical criteria were used to select markers from the current meiotic linkage and radiation hybrid maps for MSS-1. Markers were selected that (1) provided as complete coverage as possible of the canine genome, (2) were highly informative, and (3) have been ordered in linkage groups with a high degree of statistical support. This resulting screening set spans all reported meiotic linkage and RH groups, leaving only 10 known gaps > or = 20 cM. The average polymorphic information content (PIC) value of markers tested is 0.74. Coverage estimates suggest 42% of the genome is within 5 cM of at least one marker in the minimal screening set, 77% of the genome is within 10 cM. This minimal mapping set therefore provides an efficient and cost effective way to begin screening pedigrees of interest for genetic linkage.

Animals↗
PubMed2001

Cloning, sequence analysis and radiation hybrid mapping of a mammalian KRT2p gene.

We report here on the cloning, characterization and radiation hybrid mapping of the canine basic keratin gene KRT2p. The gene spans 8.3 kb, consists of nine exons and eight introns, and is characterized by the typical features of both basic keratins and keratins in general, including glycine-rich head and tail domains, which flank an alpha-helical rod domain of approximately 310 amino acids. Comparisons of sequence and structure reveal that canine KRT2p is strikingly similar to human KRT2p. Alignment of the predicted amino acid sequences for human and dog reveals greater than 80% identity. In the rod domain, the amino acid identity exceeds 90%. We note, however, that canine KRT2p encodes a protein 21 residues longer than human K2p due to the insertion of a glycine repeat motif, GG(G)X, in the head and tail domains of the canine gene. This is the first report of the nearly complete genome sequence for KRT2p of any organism. Radiation hybrid mapping of canine KRT2p to chromosome 27 of the dog is also reported.

Amino Acid Sequence↗
PubMed2001

From first base: the sequence of the tip of the X chromosome of Drosophila melanogaster, a comparison of two sequencing strategies.

We present the sequence of a contiguous 2.63 Mb of DNA extending from the tip of the X chromosome of Drosophila melanogaster. Within this sequence, we predict 277 protein coding genes, of which 94 had been sequenced already in the course of studying the biology of their gene products, and examples of 12 different transposable elements. We show that an interval between bands 3A2 and 3C2, believed in the 1970s to show a correlation between the number of bands on the polytene chromosomes and the 20 genes identified by conventional genetics, is predicted to contain 45 genes from its DNA sequence. We have determined the insertion sites of P-elements from 111 mutant lines, about half of which are in a position likely to affect the expression of novel predicted genes, thus representing a resource for subsequent functional genomic analysis. We compare the European Drosophila Genome Project sequence with the corresponding part of the independently assembled and annotated Joint Sequence determined through "shotgun" sequencing. Discounting differences in the distribution of known transposable elements between the strains sequenced in the two projects, we detected three major sequence differences, two of which are probably explained by errors in assembly; the origin of the third major difference is unclear. In addition there are eight sequence gaps within the Joint Sequence. At least six of these eight gaps are likely to be sites of transposable elements; the other two are complex. Of the 275 genes in common to both projects, 60% are identical within 1% of their predicted amino-acid sequence and 31% show minor differences such as in choice of translation initiation or termination codons; the remaining 9% show major differences in interpretation.

Animals↗