PubMed Health⌕ Search

Biomedical subjects

I Gustavsson

Publications and source records attributed to I Gustavsson.

At least 73 records · Page 4Linked to original sources
PubMed1992

Synaptonemal complex analysis of a three-breakpoint translocation in a subfertile bull.

Somatic chromosome analysis of a subfertile Brown Swiss bull demonstrated a three-breakpoint translocation involving chromosomes 1, 8, and 9 in G- and R-banded karyotypes. Based on standard bovine chromosome nomenclature, the translocation was defined as t(1;8;9)(q43;q13;q26). Synaptonemal complex analysis of the chromosome aberration by electron microscopy revealed a hexavalent configuration in 52 of 53 pachytene cells. Twenty-seven cells (51%) had a completely paired hexavalent configuration showing distinctly nonhomologous pairings between normal and/or translocated chromosomes involved in the exchanges. Thirteen cells showed a hexavalent configuration with centrally unpaired chromosome segments but with completely paired terminal arms. In 13 cells (including one at zygotene) the translocation chromosomes formed an open hexavalent, and in one cell there were two completely paired trivalents. Thirty-two cells at diakinesis-MI demonstrated 28 configurations, including one large hexavalent. Testicular histology, testis size, and seminal characteristics were normal.

Animals↗
PubMed1992

Synaptonemal complex analysis of an autosomal trisomy in the horse.

Synaptonemal complex analysis by electron microscopy of a trisomy 28 in a male horse demonstrated a trivalent or a bivalent plus a univalent in primary spermatocytes. Two of the chromosomes making up the trivalent were, most often, completely paired with each other and only partially paired or associated with the third one. Half of the spermatocytes analysed demonstrated heterologous pairing or association between the free axis of the trivalent and the sex bivalent. The pairings remained, to a large extent, into diakinesis-metaphase I. In most pachytene cells one autosomal bivalent showed proximal asynapsis and paired often, heterologously, with the trivalent or the sex bivalent. The horse demonstrated azoospermy, which was due, at least in part, to degeneration at both the spermatocyte and spermatid levels.

Animals↗
PubMed1992

Localization of the calcium release channel gene in cattle and horse by in situ hybridization: evidence of a conserved synteny with glucose phosphate isomerase.

In situ hybridization techniques were used to localize regionally the calcium release channel (CRC) gene on cattle and horse chromosomes, using a porcine CRC cDNA probe. In cattle, the hybridization signal peaked on the 18q23-q26 bands and in horse on the 10pter region. Previous studies have shown that the glucose phosphate isomerase (GPI) gene localizes at the same site in both species, indicating that the two loci are syntenic. As CRC and GPI are syntenic in human, pig and mouse, the present results in cattle and horse represent another example of synteny conservation in the evolution of mammalian chromosomes.

Animals↗
PubMed1991

Chromosomal localization of the glucose phosphate isomerase (GPI) gene in cattle, sheep and goat by in situ hybridization--chromosomal banding homology versus molecular conservation in Bovidae.

A porcine genomic glucose phosphate isomerase (GPI) DNA probe was used for in situ hybridization with metaphase chromosomes in cattle, sheep and goat. The probe gave distinct signals on the q22----proximal part of the q24 segment of chromosome 18, 14 and 18 in cattle, sheep and goat, respectively, indicating the location of GPI gene. The three species belong to the family Bovidae and have high resemblance in chromosome banding patterns. The localization of the GPI locus to the same site on chromosomes with almost similar banding patterns suggests high degree of homology at these sites in the three species. Correlation between banding homologies and possible similarities at the molecular level is discussed.

Animals↗
PubMed1991

Sister chromatid exchange in chromosomes of cattle from three different breeds reared under similar conditions.

A homogeneous group (same sex, age and environmental conditions) of 35 Italian cattle of the Podolian, Friesian, and Romagna breeds was investigated concerning the spontaneous incidence of sister chromatid exchange (SCE). The mean values of SCEs/cell were 7.9 +/- 3.4, 7.1 +/- 3.3, and 7.3 +/- 3.2 in the Podolian, the Friesian, and the Romagna breeds, respectively, with significant differences between the Podolian and the Friesian breeds. Simultaneous disclosure of SCEs and fluorescent G-bands in the lighter chromatid made possible the identification of chromosome 1, in addition to the biarmed X and Y chromosomes. The inter-chromosomal SCE-distribution revealed a nonrandom pattern due to significantly increased values of SCEs in chromosomes 1 and X, particularly in the Romagna breed.

Animals↗
PubMed1991

Somatic chromosome mutations and morphological abnormalities in sperms of boars.

Frequencies of chromosomally aberrant peripheral blood lymphocytes and morphologically abnormal spermatozoa were investigated in 10 boars from each of 11 A.I. centres. Highly significant differences were found between A.I. centres concerning both chromosomally aberrant cells and morphologically abnormal sperms. A significant correlation was found for the overall frequency of aberrant lymphocytes and morphologically abnormal sperms in A.I. centres. The coefficient of correlation was 0.675 (p = 0.022). No significant correlation was found when the 110 boars were evaluated regardless of the A.I. centre.

Animals↗
PubMed1991

Centric-fusion translocation and whole-arm heterochromatin in the karyotype of the blue fox (Alopex lagopus L.): synaptonemal complex analysis.

Conventional observations of mitotic chromosomes from two male blue foxes, revealing a centric-fusion translocation and whole-arm heterochromatin, were verified by synaptonemal complex analysis. This analysis revealed that the centric fusion had been preceded by a conspicuous loss of chromosome material in the two one-armed chromosomes involved, but the chromosomal origin of the centric-fusion kinetochore could not be established. The nontranslocated chromosomes of the trivalent, which in all cells but one were in cis configuration, had reached by early pachytene a stage in which almost complete homologous pairing and nonhomologous association or pairing of the free ends of the chromosomes could be observed. In later stages, complete pairing of the nontranslocated chromosomes with the corresponding arms of the centric-fusion translocation was seen occasionally. One to six autosomal bivalents demonstrated unpaired heterochromatic arms in early pachytene, and the heterochromatic chromosome arms were sometimes unpaired even in late pachytene. Some of them showed a distinct size heteromorphism in late zygotene and early pachytene. In most late-pachytene cells, however, the heteromorphic chromosomes were completely length-adjusted. Only a small fraction of the cells showed pairing interference between nonhomologous chromosomes.

Animals↗
PubMed1990

Benign ovarian teratomas. An analysis of their cellular origin.

To determine the cellular origin of benign ovarian teratomas with a 46,XX chromosome constitution, DNA markers recognizing restriction fragment length polymorphisms (RFLPs) were hybridized to DNA from six teratomas and their hosts. DNA markers heterozygous in the host were completely heterozygous in two of the teratomas. The remaining four showed a mixture of homozygosity and heterozygosity. These results suggests that most of the analyzed benign ovarian teratomas arose from germ cells after the first meiotic division by failure of meiosis II. Teratomas heterozygous for all tested markers may arise from failure of meiosis I. In addition, 21 cases were karyotyped and analyzed for centromeric chromosome markers to study the mechanism by which they were generated. Three of these tumors were homozygous when the host was heterozygous and therefore resulted from a failure of meiosis II or duplication of a mature ovum. Three cases were heterozygous for the centromeric chromosomal marker like the host and therefore probably originate from a premeiotic cell or a cell in which meiosis I has failed. One ovarian teratoma had an aberrant karyotype 47,XX,+8.

Alleles↗
PubMed1990

Assignment of the porcine calcium release channel gene, a candidate for the malignant hyperthermia locus, to the 6p11----q21 segment of chromosome 6.

Several studies point to the possibility that malignant hyperthermia (MH) in pigs is caused by a defect in the calcium release channel (CRC) of skeletal muscle sarcoplasmic reticulum. The locus for MH is closely linked to the glucosephosphate isomerase (GPI) locus, near the centromere of chromosome 6. We demonstrate synteny of the genes for CRC and GPI using somatic cell hybrid lines, and assign the CRC gene to chromosome 6p11----q21 by in situ hybridization.

Amino Acid Sequence↗
PubMed1989

Localization of the glucose phosphate isomerase gene to the p12----q21 segment of chromosome 6 in pig by in situ hybridization.

The glucose phosphate isomerase (GPI) locus is closely linked to the halothane sensitivity locus in pig. The chromosomal localization of GPI in pig was confirmed to 6p12----q21 by using in situ hybridization. Of the total grains, 25 percent were located on chromosome 6, with about 65 percent clustered in the cent----q21 segment, suggesting the presence of the GPI gene on the very proximal part of the q arm. The efficiency of hybridization was found to be affected by ultraviolet irradiation of metaphases for RBA-banding before hybridization. The irradiated metaphases had higher background grains than the non-irradiated metaphases.

Animals↗
PubMed1989

High-resolution studies on late-replicating segments (G + C bands) in mammalian chromosomes.

High resolution of late-replicating segments (G + C bands) in chromosomes of human, cattle and water buffalo was obtained by using 5-bromodeoxyuridine incorporation early in the cell cycle, simultaneous with methotrexate treatment combined with reduced colcemid treatment and addition of ethidium bromide, which increased the proportion of prometaphase cells. Giemsa counterstaining, following fluorescence microscopy observation and treatment with 2 x SSC, improved the resolution of the banding patterns, particularly in the pericentromeric regions. Acrocentric bovine and water buffalo chromosomes, which were seen to be C-positive by fluorescence microscopy observation and C-negative after counterstaining, showed the presence of subcentromeric G-positive bands within the heterochromatic blocks of several chromosomes.

Animals↗
PubMed1989

Banding studies and synaptonemal complex analysis of an X-autosome translocation in the domestic pig.

In a litter of nine domestic pigs, a translocation between the X-chromosome and chromosome 13 was found in six individuals: four males and two females. The translocation was presumed to have originated in the dam. Banding studies indicated that the breaks preceding the translocation had occurred in a distal GTG-negative band of the long arm of the X, 15-30% of the length of Xq from the telomere, and proximally in chromosome 13, 15-25% from the centromere. The normal X of the females invariably replicated its DNA late. Synaptonemal complex analysis of spermatocytes demonstrated a quadrivalent in 75 of 85 analyzable cells (88.2%), and in 10 cells (11.8%) one trivalent and one univalent were found. Extensive nonhomologous pairings were visualized in the pachytene stage by applying an 'overlap' test measuring the sex chromosomes and collating their pairings. An arrest in male meiosis was verified histologically; no meiotic stages later than pachytene developed. This resulted in sterility, with considerable testicular hypoplasia. The records of female fertility were available only for the dam and did not show any deviations from the average of the herd.

Animals↗
PubMed1988

Regional assignments of NP and MPI on chromosome 7 in pig, Sus scrofa.

Fibroblasts from a pig with a spontaneous reciprocal translocation involving chromosome 7, were used to prepare a set of pig-mouse somatic cell hybrids. The isozyme analysis strongly indicated that in pigs, the NP (nucleoside phosphorylase) gene is located on the distal part of the long arm of chromosome 7, (q21----qter), while the MPI (mannose phosphate isomerase) gene is in the region q21----pter. This confirmed previously reported chromosomal assignment of these genes in pigs and that this synteny has been evolutionarily conserved in several different animal species.

Animals↗