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J Gellin

Publications and source records attributed to J Gellin.

At least 55 records · Page 3Linked to original sources

Assignment of markers by using polymerase chain reaction on pools of swine flow-sorted chromosomes.

Gene chromosomal assignment can be realized not only by somatic hybrid panels but also by spot-blot hybridization or polymerase chain reaction (PCR) of flow-sorted chromosomes. We propose a swine chromosome assignment strategy by PCR amplification on pooled chromosomal DNA, which allows assignment despite possible chromosomal contamination during sorting. Each pool contains three different chromosomes, each chromosome being present in one or two pools. We present concordant results obtained for eight markers already mapped to different swine chromosomes and we assign the somatostatin gene to chromosome 13, a new marker in the pig genome.

Animals↗

A somatic cell hybrid panel for pig regional gene mapping characterized by molecular cytogenetics.

A panel of 27 pig x rodent somatic cell hybrids was produced and characterized cytogenetically. The first step of this study consisted of hybridizing a SINE probe to GTG-banded metaphases of each hybrid clone in order to count and identify the normal pig chromosomes and to detect rearranged ones. The second step consisted of using the DNA of each clone as a probe after pIRS-PCR (porcine interspersed repetitive sequence-polymerase chain reaction) amplification to highly enrich it in pig sequences. These probes, hybridized to normal pig metaphase chromosomes, enabled the identification of the complete porcine complement in the hybrid lines. Whole chromosomes and fragments were characterized quickly and precisely, and results were compared. In addition to this cytogenetic characterization, molecular verification was also carried out by using primers specific to six microsatellites and to one gene previously mapped to pig chromosomes. The results obtained allow us to conclude that we have produced a panel that is informative for all porcine chromosomes. This panel constitutes a highly efficient tool to establish not only assignments of genes and markers but also regional localizations on pig chromosomes.

Animals↗

Sequence analysis and genetic mapping of porcine chromosome 11 centromeric S0048 marker.

We report the existence of a new family of swine centromeric satellite DNA composed of a 51-bp repeat unit, most specifically found on pig chromosome 11 centromere and with less specificity at the centromeric region of other meta- and submetacentric chromosomes. This satellite DNA family, which has no homologies with the Mc1 and Ac2 families published previously, was named Mc2. We designed a specific primer set for PCR amplification of this centromeric satellite DNA. Specificity of amplification was checked by using a porcine somatic cell hybrid panel and by FISH. Furthermore, the development of a PCR-RFLP marker of Mc2 repetition allowed its genetic mapping on the PiGMaP reference families panel. The centromere of chromosome 11 was thus integrated to the genetic map previously published.

Animals↗

A linkage map with microsatellites isolated from swine flow-sorted chromosome 11.

We have developed a simple and efficient method to construct partial libraries of swine Chromosome (Chr) 11, starting with only 300 flow-sorted copies. DNA is amplified by PARM-PCR with primer containing at the 5'-end the sequence AGCU-. After amplification, digestion of PCR products with uracil DNA glycosylase generates cohesive ends corresponding to the SstI site. The amplified fragments can then be ligated in vector linearized with the SstI enzyme. Using five different primers, we PARM-PCR amplified and cloned swine Chr 11 DNA. These chromosome-specific libraries have been used to develop 14 different (TG)n microsatellites. Ten of these markers were assigned to Chr 11 by PCR analysis of a panel of Pig-Rodent somatic hybrids and by linkage analysis of the 171 individuals of the PiGMaP reference families. A complete linkage map of 147 cM of this chromosome was then realized by integrating existing markers.

Animals↗

Pig microsatellites isolated from cosmids revealing polymorphism and localized on chromosomes.

One of the most widely studied simple sequences in the mammalian genome is the (TG)n dinucleotide sequence. Because these microsatellites are highly polymorphic, we chose to study microsatellites from cosmids to provide genetic markers for the porcine genome. After screening a porcine cosmid library with a (CA)10 probe, 20 cosmids containing microsatellites were subcloned and 17 microsatellites identified by sequencing. Oligonucleotide primers flanking the repeat were designed for seven (TG)n microsatellites with n > 14. These seven microsatellites revealed polymorphism and were regionally assigned to chromosomes by fluorescent in situ hybridization of initial cosmids. These seven loci will be useful for both the construction of the genetic map and as landmark loci on the physical map of the porcine genome.

Animals↗

PCR amplification and physical localization of the genes for pig FSHB and LHB.

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are members of the glycoprotein hormone family and play essential roles in gametogenesis and sexual development of mammals. Fragments of the porcine genes coding for the beta subunits of FSH and LH were amplified by PCR and used as probes for radioactive in situ hybridization in order to map these loci in the pig. Primers were chosen on the genomic DNA nucleotide sequences of FSHB and LHB as published in GenBank. Fragments of 1,127 bp (FSHB) and 1,239 bp (LHB) were cloned and verified by sequencing. FSHB was localized to pig chromosome bands 2p1.6-->p1.2 and LHB to pig chromosome band 6q2.1. The localization of LHB to the so-called halothane region of chromosome 6 could be expected from comparative mapping data. For FSHB, no conclusions can be drawn in this respect since, up to the present, too few genes are located on porcine chromosome 2.

Animals↗

Localization of IGF1R and EDN genes to pig chromosomes 1 and 7 by in situ hybridization.

The genes coding for the insulin-like growth factor-1 receptor (IGF1R) and a porcine endothelium-derived 21-residue vasoconstrictor peptide (EDN) were localized in the pig by means of radioactive in situ hybridization. IGF1R was mapped to chromosome region 1q1.7-->q2.1 and EDN to 7p1.3-->p1.2. The results are discussed in relation to the position of their homologous loci in man.

Animals↗

Genetic markers for the Booroola fecundity (Fec) gene in sheep.

Animals from the Booroola line of Australian Merino sheep are characterized by a high ovulation rate that can be attributed to the presence of a codominant allele (FecB). The specific function of the gene has not been identified. Effective use of the trait within the sheep breeding industry requires one or more genetic markers that can distinguish between alternative alleles at the locus Fec. With a combination of DNA minisatellite markers and polymorphic protein markers, a cluster of seven minisatellite fragments has been identified as being linked to the Fec gene and to the ovine A blood group locus. The minisatellite fragments have been derived from multilocus probes and hence cannot be used to define the chromosomal location of the Fec gene or to serve as diagnostic markers for Fec. The derivation of cloned single locus markers from the minisatellite fragments will enable finer scale mapping of the Fec and the A blood group locus in sheep.

Animals↗

Rapid mapping of cosmid clones on pig chromosomes by fluorescence in situ hybridization.

Nineteen cosmids have been mapped to pig chromosomes by fluorescence in situ hybridization. Two kinds of cosmid clones were isolated as potential physical and genetic markers for the pig genome. Anonymous cosmids were obtained by screening a commercial cosmid library and were localized to Chromosomes (Chrs) 1, 2, 6, 7, 8, 10, 11, 12, 13, and 14. Some of these cosmids were found to reveal RFLP type DNA polymorphism. Microsatellite-containing cosmid clones were isolated by screening a pig cosmid library with a (CA)10 probe and were regionally mapped to Chrs 2, 6, 7, 13, and 14. Ten of the 19 chromosomes in the pig were labeled with these probes. Two-color fluorescence in situ hybridization was used to increase the efficiency of the cosmid localizations.

Animals↗

Mapping of the regulatory type I alpha and catalytic beta subunits of cAMP-dependent protein kinase and interleukin 1 alpha and 1 beta in the pig.

The genes coding for the regulatory type I alpha subunit (PRKAR1A) and the catalytic beta subunit (PRKACB) of cAMP-dependent protein kinase and the genes for interleukin 1 alpha (IL1A) and interleukin 1 beta (IL1B) were localized in the pig by means of radioactive in situ hybridization. PRKAR1A was mapped to 12p1.4 and PRKARB to 6q3.1-->q3.3. The genes for IL1A and IL1B were both assigned to Chromosome (Chr) 3, in the region q1.2-->q1.3 and q1.1-->q1.4, respectively. The cDNA nucleotide sequences of these porcine genes were compared with those of human, mouse, and cattle. The location of the genes was discussed in relation to the position of their homologous loci in these mammalian species.

Animals↗

A new marker (NGFB) on pig chromosome 4, isolated by using a consensus sequence conserved among species.

The nerve growth factor beta gene (NGFB) belongs to a conserved syntenic group on human chromosome 1 and mouse Chromosome 3. The objective of this study was the isolation of a part of the porcine NGFB gene and its use as a genetic and physical marker in the pig genome. On the basis of a nucleotide sequence comparison among different species, NGFB-specific primers were chosen to amplify the corresponding porcine sequence by PCR. A pig genomic DNA fragment of 763 bp was isolated, and its DNA sequence, containing the complete coding sequence of mature NGFB, was determined. It was demonstrated that pig NGFB is largely homologous with NGFB of other species (mouse, cattle, chicken) and especially with human NGFB; the isolated clone shows 91% nucleotide and 99% translated amino acid sequence identity to the human NGFB sequence. The porcine DNA clone allowed us to identify an RFLP marker for genetic mapping in pigs and was used to map the NGFB gene to pig chromosome region 4q1.6-->q2.3 by radioactive in situ hybridization. Previously, we had localized to the same chromosome another member of this syntenic group, the gene encoding alpha 1 Na+,K+ ATPase (ATP1A1). These results show that a portion of the homologous region between human chromosome 1 and mouse Chromosome 3 is also conserved on pig chromosome 4.

Amino Acid Sequence↗