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H Ellegren

Publications and source records attributed to H Ellegren.

89 records · Page 5Linked to original sources
PubMed1993

Conserved synteny between pig chromosome 8 and human chromosome 4 but rearranged and distorted linkage maps.

The porcine genes encoding interleukin 2, alcohol dehydrogenase (class I) gamma polypeptide, and osteopontin were mapped to chromosome 8 by linkage analysis. Together with previous assignments to this chromosome (the albumin, platelet-derived growth factor receptor A, and fibrinogen genes), an extensive syntenic homology with human chromosome 4 was discovered. Loci from about three-quarters of the q arm of human chromosome 4 are on pig chromosome 8. However, the linear order of the markers is not identical in the two species, and there are several examples of interspecific differences in the recombination fractions between adjacent markers. The conserved synteny between man and the pig gives strong support to a previous suggestion that a synteny group present in the ancestor of mammalian species has been retained on human chromosome 4q. Since loci from this synteny group are found on two cattle chromosomes, the bovine rearrangement must have occurred after the split of Suidae and Bovidae within Artiodactyla.

Alcohol Dehydrogenase↗
PubMed1993

Variable SINE 3' poly(A) sequences: an abundant class of genetic markers in the pig genome.

Previous studies on human DNA have shown that the 3' poly(A) tracts of Alu elements may display considerable genetic polymorphism. To explore whether this marker type is generally applicable in mammalian genomes, I analyzed porcine SINEs. A database screening revealed 17 porcine sequences with significant homology to a previously identified pig SINE. The occurrence in the database suggested a SINE frequency of one copy every 12 kb of pig DNA. All SINEs contained a 3' poly(A) tract with an average of 12 uninterrupted adenines. The repetitive regions were analyzed for polymorphism by locus-specific PCR amplification. Allelic length variation (two to five alleles among 10 pigs) was found at 8 out of 10 loci investigated, in most cases probably because of varying number of iterated adenine residues. There was a positive relationship between repeat length and the degree of polymorphism. Stable Mendelian inheritance was documented in 200 meioses each at four loci. The high genomic frequency of SINEs implies that a potentially informative marker may be found near any gene or in any cosmid clone. These SINE 3' poly(A) polymorphisms, termed SINEVA [SINE variable poly(A)s], thus provide an abundant and useful class of genetic marker in mammalian genomes.

Alleles↗
PubMed1993

In situ hybridization mapping and restriction fragment length polymorphism analysis of the porcine albumin (ALB) and transferrin (TF) genes.

In situ hybridization analyses were conducted on porcine metaphase chromosomes using porcine liver albumin (ALB) and transferrin (TF) cDNA probes. The ALB gene was assigned to the q12 band of chromosome 8 and the TF gene to the q31 band of chromosome 13. For the latter, a statistically significant secondary peak was observed on the 6p15 band. However, the TF probe predominantly hybridized to the 13q31 band, indicating that this band is the most likely site of the TF gene. Since the TF gene belongs to linkage group V, this linkage group can now be assigned to chromosome 13. The TF and ALB probes were also used for restriction fragment length polymorphism (RFLP) analysis. A screening of 10 unrelated animals revealed TaqI RFLPs for both ALB and TF. Family studies indicated that the ALB and TF polymorphisms were controlled by three and two alleles, respectively.

Alleles↗
PubMed1993

Strong association between polymorphisms in an intronic microsatellite and in the coding sequence of the BoLA-DRB3 gene: implications for microsatellite stability and PCR-based DRB3 typing.

A highly polymorphic microsatellite in the bovine DRB3 gene was characterized by polymerase chain reaction (PCR) analysis and DNA sequencing. A very strong association between expressed DRB3 polymorphism and microsatellite alleles was revealed by PCR analysis of genomic DNA from 116 animals representing three breeds of cattle. The results indicated a low frequency of microsatellite length mutations as the association was consistent over breeds. The DRB3 microsatellite may be utilized in a PCR-based typing method of bovine class II alleles. The microsatellite polymorphism did not distinguish all known DRB3 alleles, but it was shown that this method may be complemented by the use of allele-specific PCR based on the extensive polymorphism in the DRB3 exon 2. The DNA sequences of seven microsatellite alleles, associated with different class II haplotypes, were determined. The DRB3 microsatellite is composed of three repeat motifs, a stretch of at least 10 uninterrupted (TG)n dinucleotides, a long but interrupted stretch of (GA)n dinucleotides, and a few (CAGA)n tetranucleotides. There were pronounced sequence differences between alleles and the results indicated that the evolution of this microsatellite has involved length mutations of the dinucleotide repeats as well as point mutations causing interruptions in the dinucleotide repeats.

Alleles↗
PubMed1993

Abundant (A)n.(T)n mononucleotide repeats in the pig genome: linkage mapping of the porcine APOB, FSA, ALOX12, PEPN and RLN loci.

A computer analysis revealed that the mononucleotide repeat (A)n.(T)n is about five times as common as (CA)n.(GT)n repeats in the porcine genome, with frequency estimates of one every 7kb and 30kb, respectively. Seven mononucleotide repeats with n = 12-25 located close to coding sequences were analysed for polymorphism using polymerase chain reaction (PCR) amplification and polyacrylamide gel electrophoresis. All loci were variable with 3-6 alleles and heterozygosities of 0.26-0.69 based on investigation of 10 unrelated pigs (two wild boars and eight domestic sows). Repeat length correlated with degree of polymorphism. A comparison with (CA)n.(GT)n polymorphisms suggested that the number of repeat units rather than the total length of the repeat region is the common denominator that governs polymorphism at both mono- and dinucleotide repeat loci. (A)n.(T)n polymorphisms allowed linkage mapping of relaxin to chromosome 1, apolipoprotein B to chromosome 3, aminopeptidase N to chromosome 7, arachidonate 12-lipoxygenase to chromosome 12, and follistatin to chromosome 16. The rich abundance of potentially informative (A)n.(T)n repeats will increase the chances of finding a PCR-based marker near any DNA sequence of interest.

Aminopeptidases↗
PubMed1992

The gene for dominant white color in the pig is closely linked to ALB and PDGRFRA on chromosome 8.

White is a widespread coat color among domestic pig breeds and is controlled by an autosomal dominant gene I. The segregation of this gene was analyzed in a reference pedigree for gene mapping developed by crossing the European wild pig and a Large White domestic breed. The gene for dominant white color was shown to be closely linked to the genes for albumin (ALB) and platelet-derived growth factor receptor alpha (PDGFRA) on chromosome 8. An unexpected phenotype with patches of colored and white coat was observed among the F1 and F2 animals. The segregation data indicated that the phenotype was controlled by a third allele, denoted patch (Ip), most likely transmitted by one of the Large White founder animals. It is shown that the ALB, PDGFRA, I linkage group shares homologies with parts of mouse chromosome 5, human chromosome 4, and horse linkage group II, all of which contain dominant genes for white or white spotting. Candidate genes for the dominant white and patch mutations in the pig are proposed on the basis on these linkage homologies and the recent molecular definition of the dominant white spotting (W) and patch (Ph) mutations in the mouse.

Albumins↗
PubMed1992

Cloning of highly polymorphic microsatellites in the horse.

We have isolated equine microsatellites by screening a genomic library with (TG)n and (TC)n probes. TG microsatellites were found to be more abundant than TC repeats, with an estimated frequency of one per 100,000bp. Sequence analysis of eight TG-positive clones revealed varying structures of the repeat regions; perfect stretches of TG repeats, imperfect stretches of TG repeats and compound regions of TG and TC repeats. Five loci were analysed by PCR and showed extensive polymorphism; three to seven alleles and heterozygosities of 0.40-0.76 were observed when screening 20-30 unrelated individuals. The high degree of polymorphism, their abundance and the possibility of automating the typing procedure make these loci ideal for standardized paternity testing in the horse. Furthermore, we demonstrate that single hairs can be used as starting material for the PCR analysis.

Animals↗
PubMed1992

Multiple restriction fragment length polymorphisms in the porcine calcium release channel gene (CRC): assignment to the halothane (HAL) linkage group.

Two cDNA probes for the porcine calcium release channel gene (CRC) were used in restriction fragment length polymorphism (RFLP) analysis in an attempt to develop genetic markers linked to the malignant hyperthermia (stress susceptibility) gene (HAL). Three TaqI RFLPs, denoted CRC1-CRC3, each composed of two alleles, were detected. RFLPs were also detected with MspI and PvuII, but the MspI RFLP correlated completely with CRC3 in this material and the PvuII RFLP could not be scored reliably due to a minute size difference between the two allelic fragments. The autosomal codominant inheritance of these RFLP loci was confirmed by family analyses. Significant evidence for genetic linkage between the CRC1/CRC3 loci and the A1BG locus in the HAL linkage group confirmed a previous assignment of the CRC gene to chromosome 6 in the pig.

Animals↗
PubMed1992

DNA fingerprinting in horses using a simple (TG)n probe and its application to population comparisons.

A synthetic polynucleotide (TG)n was hybridized to equine DNA digested with HinfI and hypervariable hybridization patterns were obtained. Mendelian inheritance of these DNA fingerprinting patterns was confirmed by pedigree analysis. Estimates of the probabilities of identical band patterns in unrelated individuals of different breeds (Swedish Trotters, North Swedish Trotters, Thoroughbreds and Arabians) were in the range 1 x 10(-4) - 7 x 10(-6). The variability derived with the (TG)n probe in horses was higher than what we obtained with several other commonly used probes for DNA fingerprinting. Individuals within breeds tended to be more similar to each other with regard to DNA fingerprint pattern than to individuals of other breeds. Moreover, a parsimony analysis made on the basis of the hybridization patterns gave clustering of individuals within breeds. The possibility of using hypervariable probes for the identification of breed-specific characters is discussed.

Animals↗
PubMed1989

Size-exclusion chromatography of DNA restriction fragments. Fragment length determinations and a comparison with the behaviour of proteins in size-exclusion chromatography.

Size-exclusion chromatography of double-stranded DNA restriction fragments on Superose 6 is shown to be an accurate method for chain length determination of unknown DNA. Ionic interaction was observed between DNA and the gel matrix but was easily prevented by the addition of 0.15-0.2 M sodium chloride to the eluent. Compared to protein, the selectivity curve of DNA fragments was found to be steeper reflecting the different chromatographic behaviour of rod-like and globular molecules. The relationships between the selectivity curves of DNA and protein were similar on Superose 6 and on Sephacryl S-500.

Chromatography, Gel↗
PubMedDate not supplied

The extension coat color locus and the loci for blood group O and tyrosine aminotransferase are on pig chromosome 6.

A linkage map of pig chromosome 6 was constructed using a wild pig/Large White intercross pedigree. The map comprises 23 polymorphic loci, and the sex-average map length is approximately 170 cM. The study adds three new genes to the chromosome 6 map: the extension (E) coat color locus, and the blood group O (EAO) and tyrosine aminotransferase (TAT) loci. Segregation at the E locus determined two coat color phenotypes among the F2 animals: wild-type color (El-) and black-spotting (Ep/Ep). The E locus showed close genetic linkage to the most distal marker (S0035) on the short arm of chromosome 6. Comparative coat color genetics as well as comparative mapping strongly suggest that E in pigs encodes the melanocyte-stimulating hormone receptor, as previously shown for the corresponding coat color loci in mouse and cattle. TAT was also mapped to the distal part of 6p, whereas EAO was the most distal marker on 6q. A clear tendency for a higher recombination rate in both terminal regions was observed. A model for the evolution of pig chromosome 6, based on comparative mapping data, is presented.

ABO Blood-Group System↗
PubMedDate not supplied

Cloning and characterization of highly polymorphic porcine microsatellites.

A size-fractionated (200-400 bp) porcine genomic library was screened with the dinucleotide motifs (TG)n and (TC)n. The number of TG- and TC-positive clones was 83 and four, respectively, implying that the former motif is more frequent in the porcine genome, as previously reported in other species. Twenty-six TG-clones were sequenced, and the number of repeats varied between 16 and 42 with different compositions of the repetitive sequences; 17 clones had a perfect stretch of TG-repeats, four had imperfect stretches, and five had a compound structure with TG-repeats followed by TC-repeats. Primers for DNA amplification using the polymerase chain reaction (PCR) were synthesized for six loci. Ten unrelated individuals (two wild boars and eight domestic pigs of the Swedish Yorkshire breed) were screened for microsatellite polymorphism. All six microsatellite loci were polymorphic with two to seven alleles and observed heterozygosities in the range of 0.42-0.84; the inheritance of the observed polymorphism was confirmed by family studies. The characteristics of microsatellites make them highly suitable as genetic markers, and these microsatellites were isolated as a part of a pig gene mapping project.

Animals↗
PubMedDate not supplied

Genetic analysis of the gene for porcine submaxillary gland mucin: physical assignment of the MUC and interferon gamma genes to chromosome 5.

Genetic variation at the porcine submaxillary gland mucin (MUC) locus was revealed by RFLP analysis. A three-allele system was defined, and codominant inheritance was confirmed using a three-generation pedigree comprising 10 founder individuals, 26 F1 animals, and 200 F2 offspring. Linkage analysis was performed against a set of 56 genetic markers. The mucin locus was assigned to a previously reported linkage group comprising the markers interferon gamma (IFNG), diacylglycerol kinase (DAGK), and an anonymous microsatellite (S0092). Furthermore, the genes for mucin and interferon gamma were physically localized to porcine chromosome 5q2.3 and 5p1.2-q1.1 by fluorescence and radioactive in situ hybridization, respectively, thereby assigning four new markers to chromosome 5. This chromosome shares homologies with chromosome 5 in cattle and chromosome 12 in humans.

Animals↗