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I Gustavsson

Publications and source records attributed to I Gustavsson.

At least 37 records · Page 2Linked to original sources

Zoo-FISH delineates conserved chromosomal segments in horse and man.

Human chromosome specific libraries (CSLs) were individually applied to equine metaphase chromosomes using the fluorescence in situ hybridization (FISH) technique. All CSLs, except Y, showed painting signals on one or several horse chromosomes. In total 43 conserved chromosomal segments were painted. Homoeology could not, however, be detected for some segments of the equine genome. This is most likely related to the very weak signals displayed by some libraries, rather than to the absence of similarity with the human genome. In spite of divergence from the human genome, dated 70-80 million years ago, a fairly high degree of synteny conservation was observed. In seven cases, whole chromosome synteny was detected between the two species. The comparative painting results agreed completely with the limited gene mapping data available in horses, and also enabled us provisionally to assign one linkage group (U2) and one syntenic group (NP, MPI, IDH2) to specific equine chromosomes. Chromosomal assignments of three other syntenic groups are also proposed. The findings of this study will be of significant use in the expansion of the hitherto poorly developed equine gene map.

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A comparative map of the porcine and human genomes demonstrates ZOO-FISH and gene mapping-based chromosomal homologies.

ZOO-FISH with chromosome-specific DNA libraries (CSLs) from individual flow-sorted human chromosomes was applied on porcine metaphase chromosomes to establish segment homology between the pig and human karyotypes. Forty-seven porcine chromosomal segments corresponding to all human chromosomes except the Y were delineated, resulting in a nearly complete coverage of the porcine karyotype. The syntenic segments detected were further confirmed by the gene mapping information available in the two species. A map demarcating physical boundaries of human homologies on individual pig chromosomes is complemented with a detail survey of the physical and genetic linkage mapping data in the two species. The resultant map, thus, provides a comprehensive and updated comparative status of the human and porcine genomes.

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Comparative analysis of the cattle and human genomes: detection of ZOO-FISH and gene mapping-based chromosomal homologies.

Comparative chromosome painting with individual human chromosome-specific libraries (CSLs) on cattle metaphase chromosomes delineated 46 homologous chromosomal segments between the two species. Continuous arrangement of these segments on individual cattle chromosomes demonstrates a nearly complete coverage of the bovine karyotype and shows physical boundaries of bovine chromosomal segments homologous to individual human chromosomes. Alignment of the available comparative gene mapping data with the homologous segments strongly supports the detected gross homologies between the karyotypes of the two species. In addition to cattle, four human CSLs were hybridized to sheep metaphase chromosomes also, to further verify the known karyotype homology within the Bovidae. Besides its application to karyotype evolution research, the comparative knowledge provides for rapid expansion of the much needed Type I locus-based bovine gene map.

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Reproductive disorders in 10 domestic male cats.

This study describes 10 tomcats with different reproductive disorders. Two of the cats had abnormal sex chromosomes; one was a tortoiseshell and white Cornish rex, while the other was a brown Burmese. The other eight cats were diagnosed as having testicular hypoplasia, diphallos in combination with unilateral cryptorchidism, a persistent penile frenulum, retrograde ejaculation, temporary oligozoospermia, teratozoospermia, azoospermia and congenital poor libido. For the cat with a persistent penile frenulum, and the cat with a temporary oligozoospermia, the prognosis for successful reproduction was considered favourable. By contrast it was considered unlikely that the cats with chromosomal abnormalities, testicular hypoplasia, diphallos, retrograde ejaculation, teratozoospermia and azoospermia would be able to produce offspring.

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cDNA sequence and chromosome localization of pig alpha 1,3 galactosyltransferase.

Human serum contains natural antibodies (NAb), which can bind to endothelial cell surface antigens of other mammals. This is believed to be the major initiating event in the process of hyperacute rejection of pig to primate xenografts. Recent work has implicated galactosyl alpha 1,3 galactosyl beta 1,4 N-acetyl-glucosaminyl carbohydrate epitopes, on the surface of pig endothelial cells, as a major target of human natural antibodies. This epitope is made by a specific galactosyltransferase (alpha 1,3 GT) present in pigs but not in higher primates. We have now cloned and sequenced a full-length pig alpha 1,3 GT cDNA. The predicted 371 amino acid protein sequence shares 85% and 76% identity with previously characterized cattle and mouse alpha 1,3 GT protein sequences, respectively. By using fluorescence and isotopic in situ hybridization, the GGTA1 gene was mapped to the region q2.10-q2.11 of pig chromosome 1, providing further evidence of homology between the subterminal region of pig chromosome 1q and human chromosome 9q, which harbors the locus encoding the AB0 blood group system as well as a human pseudogene homologous to the pig GGTA1 gene.

Amino Acid Sequence↗

Reciprocal chromosome translocation, rcp(7;17)(q26;q11), in a boar giving reduced litter size and increased rate of piglets dying in the early life.

Cytogenetic investigations in a boar causing a 41% reduction in litter size and also producing piglets that died soon after birth revealed the presence of a reciprocal chromosome translocation, rcp(7;17)(q26;q11). The translocation resulted in one extremely small telocentric chromosome marker. Synaptonemal complex analysis of spread spermatocytes by electron microscopy revealed an unusual behaviour of the translocation. This formed not only different types of quadrivalents (78.1% of the cells), similar to those previously found in boars heterozygous for reciprocal exchanges, but also completely or incompletely paired trivalent configurations, plus univalent (21.9%). Association between the sex bivalent and the translocation configuration was observed (18.7%), but testicular histology was normal. Furthermore, the boar with the translocation was found to produce tertiary monosomy and trisomy in some of the liveborn piglets. Some of the tertiary monosomic offspring, which died in the early extra-uterine life, demonstrated ventricular septal defect and cleft palate.

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Synaptonemal complex analysis in a boar with tertiary, trisomy, product of a rcp(7;17)(q26;q11) translocation.

Synaptonemal complex analysis by electron microscopy showed a trivalent formed by pairing of chromosome 17(7) with chromosome pair 7 in two zygotene cells. In 89 pachytene cells (75.4%) the chromosome 17(7) occurred as a univalent with the axis being unpaired, in the shape of a ring (60.6%), a rod (38.2%) or self-paired (1 cell). Thirty-four (38.2%) of the univalents were paired or associated with the sex bivalent. Twenty-five (21.2%) of the 118 pachytene cells analysed demonstrated different types of trivalent pairing: the 17(7) chromosome paired with chromosome pair 7 in 24 cells and with pair 17 in one cell. Moreover, in 4 cells, chromosome 17(7) was paired with both pair 7 and pair 17, forming a pentavalent. Trivalent association with XY was observed in 4 cells. Nineteen bivalents plus a univalent (8 cells), and eighteen bivalents plus a trivalent (11 cells), were found during conventional meiotic investigation of diakinesis-metaphase I. Though the boar demonstrated a normal testicular histology, a qualitatively deviant semen picture was evident.

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Localization of the telomeric (TTAGGG)n sequences in chromosomes of some domestic animals by fluorescence in situ hybridization.

Fluorescence in situ hybridization analysis was carried out on metaphase preparations of a variety of domestic animal species, viz. pigs, cattle, sheep, river buffaloes, swamp buffaloes, horses, and reindeers, using a PCR generated human telomere repeat probe (TTAGGG)n. Three protocols with different hybridization/washing stringencies were applied. Distinct double spots representing the telomeric sites were observed on either ends of the chromosomes in all the species studied, confirming that one-armed chromosomes are not completely telocentric. In pigs, an interstitial telomeric signal was observed on the 6q22 band of all the individuals examined. Although a random variation in the intensity of signals was observed, it was interesting to note that in one of the five cattle studied, very strong hybridization signals were seen on at least three pairs of chromosomes. In sheep, river buffaloes, and swamp buffaloes, where the biarmed chromosomes are considered to be the result of the fusion of 2-3 one-armed chromosomes of the cattle karyotype, no interstitial telomeric signals were observed.

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In situ hybridization mapping of a 500-kDa calcium-sensing protein gene (LRP2) to human chromosome region 2q31-->q32.1 and porcine chromosome region 15q22-->q24.

Recently, a 500-kDa protein, with homology to the rat Gp330 glycoprotein, was found to be expressed on the surface of human parathyroid, placental cytotrophoblast, and renal proximal tubule cells. The protein has been implicated to function as a sensor of extracellular calcium on parathyroid and placental cytotrophoblast cells. We report here in situ hybridization mapping of the corresponding gene, designed as low-density lipoprotein receptor related protein-2 and symbolized as LRP2, to human chromosome region 2q31-->q32.1 and porcine chromosome region 15q22-->q24. The results are discussed in a comparative mapping context.

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FISH on metaphase and interphase chromosomes demonstrates the physical order of the genes for GPI, CRC, and LIPE in pigs.

The porcine genes for glucose phosphate isomerase (GPI), calcium release channel (CRC), and hormone-sensitive lipase (LIPE) map to the long arm of chromosome 6. Earlier studies, using fluorescence in situ hybridization (FISH), mapped the three loci to the same band, viz., 6q12. To ascertain the relative order of the three genes, we first conducted three double-color FISH experiments, cohybridizing two of the probes at a time. These experiments demonstrated that the gene order was cen-GPI-CRC-LIPE. This order was confirmed by cohybridizing the three probes to both metaphase and interphase chromosomes.

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Localization of the IGHG, PRKACB, and TNP2 genes in pigs by in situ hybridization.

The porcine genes encoding the immunoglobulin gamma heavy chain (IGHG), cAMP-dependent protein kinase catalytic beta subunit (PRKACB), and transition protein 2 (TNP2) were mapped to Chromosomes (Chrs) 7 q25-q26, 6q31-q33, and 3p13-cent, respectively, by in situ hybridization. Localization of the IGHG gene confirms the assignment of linkage group III to Chr 7. Our results show that the IGHG locus in pigs, similar to the situation in other mammalian species, viz. humans, mouse, cattle, and river buffaloes, is located on the terminal region of the chromosome. The assignment of the PRKACB gene extends the homology observed between porcine Chr 6q and human Chr 1p. Mapping of the TNP2 gene provides the first marker assigned to the p arm of Chr 3 in pigs. The present study contributes to the development of the physical gene map in pigs and also bears significance in terms of comparative gene mapping.

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A primary linkage map of the porcine genome reveals a low rate of genetic recombination.

A comprehensive genetic linkage map of the porcine genome has been developed by typing 128 genetic markers in a cross between the European Wild Boar and a domestic breed (Large White). The marker set includes 68 polymerase chain reaction-formatted microsatellites, 60 anchored reference markers informative for comparative mapping and 47 markers which have been physically assigned by in situ hybridization. Novel multipoint assignments are provided for 54 of the markers. The map covers about 1800 cM, and the average spacing between markers is 11 cM. We used the map data to estimate the genome size in pigs, thereby addressing the total recombination distance in a third mammalian species. A sex-average genome length of 1873 +/- 139 cM was obtained by comparing the recombinational and physical distances in defined regions of the genome. This is strikingly different from the length of the human genome (3800-4000 cM) and is more similar to the mouse estimate (1600 cM). The recombination rate in females was significantly higher than in males.

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Mapping of the interferon gamma (IFNG) gene in river and swamp buffaloes by in situ hybridization.

In situ hybridization technique was applied using a tritiated (3H) bovine IFNG cDNA probe to regionally localize the gene on river and swamp buffalo chromosomes. The hybridization signals peaked on the 4q23-->q26 bands in river buffaloes and on the 1p24-->p26 bands in swamp buffaloes. The results are compared to the localization of the same gene in cattle. Possible evolutionary conservation in the Bovidae is discussed.

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