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PubMed2002

Infertility status of male individuals with abnormal spermiogram evaluated by cytogenetic analysis and in vitro sperm penetration assay.

BACKGROUND: The possibility of a link between altered sperm morphology and functional ability, possibly reflected on the genetic level, is still a matter of controversy. MATERIAL/METHODS: 60 infertile males with pathological spermiogram and 14 healthy individuals with confirmed in vivo fertility were selected for our study. Ejaculated sperm was assessed according to the standard criteria set by the World Health Organization, which constituted a basis for subgroup classification. The sperm penetration assay (SPA) using human sperm and hamster oocytes was subsequently performed with concomitant cytogenetic analysis of peripheral blood leukocytes (PBL). RESULTS: More than 55% of infertile males with pathological spermiogram exhibited a decreased ability for penetration of the oocyte (SPAL30%). The lowest penetration ability was observed in the semen of patients with oligoasthenoteratozoospermia (OAT), of whom as many as 75% presented negative SPA values. We noted only 1 case of chromosome aberration (Robertsonian translocation) in the analyzed cohort of infertile patients. Strikingly, in the identified group of infertile patients with chromosome structural polymorphism (acrocentric chromosomes), we revealed a statistically significant decreased rate of sperm - oocyte penetration. CONCLUSIONS: A causative link may exist between sperm malfunction and a specific feature of the chromosome variants detected in the blood leukocytes of infertile males with pathological spermiogram.

Adult↗
PubMed1992

[Cytogenetic changes in persons exposed to polychlorinated biphenyls].

A cytogenetic study performed in a group of workers exposed to polychlorinated biphenyls comprised analysis of structural chromosomal aberrations in the lymphocytes in the first division in vitro, analysis of micronuclei frequency in binuclear lymphoblasts induced by cytochalasin B and analysis of sister chromatid exchanges. The study included 48 exposed workers and 15 controls. In 16 exposed workers increased incidence of unstable chromosomal aberrations (dicentrics, rings and acentrics) was found, while in 19 no structural chromosomal aberrations could be detected. In 11 workers changes defined as chromosomal and chromatid breaks were noted. This type of change, however, can be evidenced in a non-exposed population as well. In two workers stable chromosomal aberrations were recorded (translocations and inversions). The incidence of micronuclei as well as exchange of sister chromatids were elevated in the exposed group of workers compared to controls.

Adult↗
PubMed2003

[Characterization of Amycolatopsis meditteranei U32 chromosome by pulse-field gel electrophoresis].

Amycolatopsis meditteranei U32 is an industrial strain with high yield of rifamycin SV. Its chromosome structure was characterized by pulse-field gel electrophoresis. The topological structure of U32 chromosome was linear and its genome size was about 10 Mb. There was no internal plasmid found. Gene encoding several enzymes involved in rifamycin bio-synthesis and relevant primary metabolism as well as protein related to metabolic regulation were localized by Southern blot. The results revealed that there were at least five copies of rrn operon in U32. The rifamycin bio-synthesis gene cluster was located on one about 700 kb PshBI fragement where several other important genes related to primary and secondary metabolism were also situated. They were the nasD gene, the mcm gene encoding methylmalonyl CoA mutase, the accA gene encoding acethyl CoA carboxylase biotin carrier protein and one copy of the rrn operons.

Actinomycetales↗
PubMed1978

[Increase with age of the frequency of spontaneous karyotype disorders in mice].

328 oocytes from 874 studied were found suitable for counting chromosomes. 263 oocytes (80.18%) had a normal chromosome number, while aneuploidy was observed in 18.3% of oocytes (61). Among then 46 (14.02%) were with hypoploidy and 14 oocytes (4.26%) were hyperploid with 21 chromosomes and over. Structural chromosome aberrations were found in 24 oocytes (7.31%).

Age Factors↗
PubMed1980

Consistent chromosome abnormalities associated with mouse bladder epithelial cell lines transformed in vitro.

Nine epithelial tumor cell lines that were derived from inbred C57BL/lcrf-at adult male mouse bladder and were transformed in vitro were cytogenetically analyzed. Most cell lines were near-diploid and showed only minor karyotypic deviations from normal. Tetraploid cell lines showed duplication of chromosome markers, which suggested that they arose originally as near-diploid cell lines with minor karyotypic changes. Chromosome abnormalities were consistent among different cell lines and involved chromosomes #6, #3, and #15. The Y-chromosome was frequently missing. Identical chromosome abnormalities were present in cell lines that arose in control, dimethyl sulfoxide-treated, or 7, 12-dimethylbenz[a]anthracene-treated cultures. The most frequent abnormality was was the presence of three copies (trisomy) of chromosome #6. Few structural chromosome abnormalities were detected, although a marker chromosome derived from chromosome #3 was present in several cell lines. Two cell lines had excesses of chromosome #15. These results suggest that excesses of individual chromosomes or parts of chromosomes, particularly chromosome #6, may be important in the expression of the malignant phenotype in mouse bladder epithelium.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1997

Genomic structure and chromosomal mapping of the nuclear orphan receptor ROR gamma (RORC) gene.

The nuclear orphan receptor subfamily ROR/RZR is part of the steroid and thyroid hormone/retinoid receptor superfamily and consists of three different genes, alpha, beta, and gamma. In this study, we determined the genomic structure of mouse ROR gamma and the chromosomal localization of both mouse ROR gamma and human ROR gamma (HGMW-approved symbol RORC). The genomic structure of the mouse ROR gamma gene was derived from the analysis of P1 vector clones containing large genomic fragments encoding ROR gamma. These results revealed that the mROR gamma gene has a complex structure consisting of 11 exons separated by 10 introns spanning more than 21 kb of genomic DNA. The DNA-binding domain is contained in two exons, 3 and 4, each encoding one zinc-finger. The splice site between exon 3 and exon 4 is identical to that found in RAR and TR3 receptors. ROR gamma is expressed as two mRNAs, 2.3 and 3.0 kb in size, that are derived by the use of alternative polyadenylation signals. We show by fluorescence in situ hybridization that the mouse ROR gamma gene is located on chromosome 3, in a region that corresponds to band 3F2.1-2.2. The human ROR gamma was mapped to chromosome region 1q21. The results demonstrate that the ROR gamma genes are located in chromosomal regions that are syntenic between mouse and human.

Alternative Splicing↗
PubMed2005

Genetic structure and chromosomal integration site of the cryptic prophage CP-1639 encoding Shiga toxin 1.

The sequence of 50 625 bp of chromosomal DNA derived from Shiga-toxin (Stx)-producing Escherichia coli (STEC) O111: H- strain 1639/77 was determined. This DNA fragment contains the cryptic Stx1-encoding prophage CP-1639 and its flanking chromosomal regions. The genome of CP-1639 basically resembles that of lambdoid phages in structure, but contains three IS629 elements, one of which disrupts the gene of a tail fibre component. The prophage genome lacks parts of the recombination region including integrase and excisionase genes. Moreover, a capsid protein gene is absent. CP-1639 is closely associated with an integrase gene of an ancient integrative element. This element consists of three ORFs of unknown origin and a truncated integrase gene homologous to intA of CP4-57. By PCR analysis and sequencing, it was shown that this integrative element is present in a number of non-O157 STEC serotypes and in non-STEC strains, where it is located at the 3'-end of the chromosomal ssrA gene. Whereas in most E. coli O111: H- strains, prophages are inserted in this site, E. coli O26 strains contain the integrative element not connected to a prophage. In E. coli O103 strains, the genetic structure of this region is variable. Comparison of DNA sequences of this particular site in E. coli O157: H7 strain EDL933, E. coli O111: H- strain 1639/77 and E. coli K-12 strain MG1655 showed that the ssrA gene is associated in all cases with the presence of foreign DNA. The results of this study have shown that the cryptic prophage CP-1639 is associated with an integrative element at a particular site in the E. coli chromosome that possesses high genetic variability.

Chromosome Mapping↗
PubMed1998

Gene and locus structure and chromosomal localization of the protease-activated receptor gene family.

Protease-activate receptors (PARs) mediate activation of platelets and other cells by thrombin and other proteases. Such protease-triggered signaling events are thought to be critical for hemostasis, thrombosis, and other normal and pathological processes. We report here the structure of the mouse and human PAR3 genes as well as the organization of a PAR gene cluster encompassing the genes encoding PARs 1, 2, and 3. We also report the structure of the mouse and human PAR4 genes, which map to distinct chromosomal locations and encode a new thrombin receptor. PARs 1-4 are all encoded by genes with the same two exon structure. In each case, exon 1 encodes a signal peptide, and exon 2 encodes the mature receptor protein. These are separated by an intron of variable size. The genes encoding PARs 1-3 all map to chromosome 13D2 in mouse and chromosome 5q13 in human. In mouse, all three genes are located within 80 kilobases of each other. The PAR1 gene is located centrally and is flanked upstream by the PAR3 gene and downstream by the PAR2 gene in both species. The proximity of the PAR1 and PAR3 genes suggests the possibility that these genes might share regulatory elements. A comparison of the structures of the PAR amino acid sequences, gene structures, locus organization, and chromosomal locations suggests a working model for PAR gene evolution.

Animals↗
PubMed1992

Primary structure and chromosomal localization of human and mouse rod photoreceptor cGMP-gated cation channel.

We have determined the primary structures of the human and mouse retinal rod cGMP-gated cation channel by analysis of cDNA clones and amplified DNA. The open reading frames predicted polypeptides of 690 and 683 residues exhibiting 88% sequence similarity. Sequence comparison indicated that the rod channels consist of a variable 90-residue N-terminal region, a short highly charged segment rich in lysine and glutamate, and a 540-residue C-terminal portion that is well conserved in three mammalian species. Significant sequence similarity (59%) of the visual cGMP-gated channel to the olfactory cAMP-gated channel established the existence of a family of cyclic nucleotide-gated ion channel genes. RNA blot analysis revealed transcripts of 3.2 kilobases (kb) in human, mouse, and dog, 3.2, 4.6, and 5.2 kb in bovine, and 3.6 kb in fish. The human channel gene was mapped by polymerase chain reaction of somatic cell hybrid DNAs to chromosome 4 (p14-q13) near the centromere. The mouse channel gene locus (Cncg) was mapped by interspecific backcross haplotype analysis 0.9 centimorgan proximal of the Kit locus on chromosome 5.

Amino Acid Sequence↗
PubMed2000

Genomic structure and chromosomal localization of the human hepatocyte growth factor activator inhibitor type 1 and 2 genes.

Hepatocyte growth factor activator inhibitor type 1 (HAI-1) and type 2 (HAI-2) are recently discovered Kunitz-type serine protease inhibitors which can be purified and cloned from human stomach cancer cell line MKN45 as specific inhibitors against hepatocyte growth factor activator (HGFA). HAI-2 was identical with the protein originally reported as placental bikunin. Both proteins contain two Kunitz inhibitor domains (KDs), of which the first domain (KD1) is mainly responsible for the inhibitory activity against HGFA, and are expressed ubiquitously in various tissues. In this study, we cloned the genes coding for these two structurally similar proteins by screening of human genomic bacterial artificial chromosome (BAC) library and their genomic structures were compared. HAI-1 and -2 genes consist of 11 and 8 exons spanning 12 kbp and 12.5 kbp, respectively. Three exons were inserted between KD1 and KD2 of each gene, of which the middle one was the low-density lipoprotein (LDL) receptor-like domain (HAI-1) and the testis specific exon (HAI-2). Apparently homologous regions between HAI-1 and -2 were not found in 5'-flanking region and neither TATA nor CAAT box was present. The genes were mapped to chromosome 15q15 (HAI-1) and 19q13.11 (HAI-2). These results suggested that although HAI-1 and -2 genes might be derived from same ancestor gene, they acquired distinctive in vivo roles during their evolution.

Amino Acid Sequence↗
PubMed1991

Cytogenetic analysis of human bile for mutagenicity and co-mutagenicity.

Cytogenetic analysis was used to test whether or not human bile induced chromosome abnormalities in lymphocytes grown in culture. Bile was obtained from gallbladders resected for various reasons such as cholecystitis, cholelithiasis, polypus and cancers of the biliary tract, stomach and pancreas. After adding human bile to a final concentration of 25 microliters/ml or 12.5 microliters/ml, the culture medium was incubated at 37 degrees C for 72 hr. Air-dried slides were stained with conventional Giemsa and the numerical and structural chromosome abnormalities were scored. Positive and negative controls in terms of chromosome abnormalities were established by using 0.03 micrograms/ml mitomycin C (MMC) and 0.9% normal saline, respectively. Cytogenetic analysis was successfully performed in 6 out of 10 bile samples (60.0%). Bile alone did not induce numerical or structural chromosome abnormalities. Structural abnormalities increased significantly in the 25 microliters/ml bile + 0.03 micrograms/ml MMC group, compared with the 0.03 micrograms/ml MMC group: 36.0% vs. 20.7% in the chromatid-type gaps and breaks, 27.8% vs. 22.7% in the chromosome-type gaps and breaks, and 8.3% vs. 3.2% in the exchange-type abnormalities. It is likely that the interaction between bile and MMC is synergistic rather than additive.

Adult↗
PubMed1994

High resolution detection of uncoated metaphase chromosomes by means of field emission scanning electron microscopy.

HeLa metaphase chromosomes were examined by means of "in lens" field emission scanning electron microscopy, which permits high resolution detection of uncoated biological samples. By using uncoated chromosomes as a model for comparison we report evidence of how traditional scanning electron microscopy techniques such as metal coating and conductive methods can generate errors in chromosome structure evaluation, since both give rise to morphological artifacts. By comparing the morphology of uncoated chromosomes obtained by two different isolation procedures, such as that utilized in standard cytogenetics and the polyamine method, we have drawn the following conclusions: (a) the standard cytogenetic method gives rise to a chromosome structure consisting of a flattened network of 10 nm fibers, in which higher order chromatin organization is absent. (b) Chromosomes obtained by the polyamine method show both three-dimensional profile and higher level folding of chromatin fibers, supporting the loop chromosome organization previously suggested by scanning electron microscopy observation of hexylene glycol isolated chromosomes.

Chromosomes, Human↗
PubMed1998

The human glycine receptor beta subunit gene (GLRB): structure, refined chromosomal localization, and population polymorphism.

The glycine receptor of the human CNS comprises ligand-binding alpha 1 and structural beta subunits encoded by the GLRA1 and GLRB genes, respectively. Screening of a human hippocampal cDNA library resulted in the identification of the novel subunit transcript beta B, differing in the 5'-UTR. Analysis of the genomic organization of GLRB showed that the coding region is distributed over nine exons, highly homologous to the GLRA1 gene. By in situ hybridization, the chromosomal localization of GLRB was refined to band 4q31.3. Based on the identical phenotypes of mouse lines carrying mutant alleles of the alpha 1 and beta subunit genes, GLRB was assumed to be a candidate gene for those cases of hyperekplexia that cannot be associated with mutations of GLRA1. Therefore, flanking intronic sequences were determined, and DNA samples from more than 30 index patients were subjected to SSCP screening of the entire GLRB coding region. A polymorphism in exon 8 was found both in the normal population and in families affected by hyperekplexia, although no coding mutation was detectable.

Alleles↗
PubMed2001

Comparative analysis of the genetic structure and chromosomal location of the murine MyD118 (Gadd45beta) gene.

The MyD118 (Gadd45beta) protein is a member of a family of structurally related proteins, including Gadd45 (Gadd45alpha) and CR6 (Gadd45gamma), that have critical roles in regulating growth arrest and apoptosis. The MyD118 and other members of its family display distinct patterns of expression in response to stimuli that induce differentiation, growth arrest, or apoptosis. Species-blot analysis showed that MyD118 is an evolutionarily conserved gene, and comparative sequence analysis showed that MyD118 has a gene structure similar to that of other members of its gene family. Comparison of putative transcription factor-binding sites found in sequences of this gene family provides evidence that p53 is involved in regulating the expression of MyD118 and that NF-kappaB may play a role in differential expression of MyD118 and Gadd45(Gadd45alpha). Fluorescence in situ hybridization localized the MyD118 gene to mouse chromosome band 10B5.3, correcting a previous assignment to mouse chromosome 9.

Amino Acid Sequence↗
PubMed1956

The fine structure of chromosomes in the meiotic prophase of vertebrate spermatocytes.

The prophase chromosomes of the first meiotic division in pigeon, cat, and man contain a central structure or core consisting of a pair of dense fibrils (450 A) that are parallel to one another and equidistant from a delicate linear region of increased density midway between them. These parallel strands are present early in prophase and the chromosomes seem to arise by congregation and organization of the chromatin granules around them. They have not been observed in mitosis or in other stages of meiosis.

Animals↗
PubMed1998

A patient with myelodysplastic syndrome studied by GTG-banding and fluorescent in situ hybridization (FISH).

Molecular cytogenetics using fluorescent in situ hybridization (FISH) is an extremely useful adjunct technique to conventional cytogenetics via GTG-banding. The present paper illustrates the utility of FISH by describing a patient with myelodysplastic syndrome (MDS) who was initially studied using GTG-banding and whose bone marrow was found to be populated with hyperdiploid cells. FISH was used to delineate the numerical and structural chromosomal abnormalities. It revealed the presence of trisomy 8 and determined that the previously unidentifiable marker chromosome was of chromosome 10 origin. Although trisomy 8 is a frequent finding in MDS, the structural chromosomal abnormality of chromosome 10 as reported here is not a common finding.

Aged↗
PubMed1988

Cytogenetic analysis of living human oocytes: cellular basis and developmental consequences of perturbations in chromosomal organization and complement.

Chromosome complement and location were examined by fluorescence microscopy for 225 meiotically mature (metaphase II) human oocytes after staining with DNA-specific probes. Both preovulatory oocytes and oocytes that failed to fertilize in vitro were analysed. After inspection in the living state, oocytes were selected for karyotyping or transmission electron microscopy. The findings demonstrate a high correlation between assessments of chromosome complement in living oocytes and the results from subsequent karyotypes. In addition to numerical aberrations (aneuploidy), the results also demonstrate the ability to detect abnormalities in chromosome structure and distribution. Specifically, this approach identified living oocytes that (1) contained no apparent chromosomes in the ooplasm, (2) contained chromosome not associated with the MII spindle and (3) had weak or no detectable chromosomal fluorescence in the first polar body. The findings demonstrate that approximately 8% of the oocytes were aneuploid (hypohaploid or hyperhaploid). Another 6.5% displayed anomalies in chromosome structure or distribution that could lead to aneuploid situations. The results are discussed with respect to the origin, occurrence and developmental consequences for such oocytes.

Adult↗