Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CHROMOSOMES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,513 records · Page 84Linked to original sources
PubMed2002

A maedi-visna virus strain K1514 receptor gene is located in sheep chromosome 3p and the syntenic region of human chromosome 2.

The maedi-visna lentivirus (MVV) induces encephalitis, interstitial pneumonia, arthritis and mastitis in sheep. While some MVV strains can enter cells of ruminant species only, others can enter cells from many species, including human, but not Chinese hamster cells. However, the identity of the receptor(s) used by MVV for entry is unknown. The MVV-K1514 receptor gene was localized in sheep and human chromosomes using hamster x sheep and hamster x human hybrid cell lines. Based on entry by a vector pseudotyped with the MVV-K1514 envelope, the MVV-K1514 receptor gene was mapped to sheep chromosome 3p and to a region of human chromosome 2 (2p25>q13), which has conserved synteny with sheep chromosome 3p. These regions do not include any known lentivirus receptor or coreceptor gene, indicating that MVV-K1514 uses a new lentivirus receptor to infect human cells.

Animals↗
PubMed2005

Delineation of a supernumerary marker chromosome utilizing a multimodal approach of G-banding, fluorescent in situ hybridization, confirmatory P1 artificial chromosome fluorescent in situ hybridization, and high-resolution comparative genomic hybridization.

We describe the structure of a supernumerary marker in a child who presented with a right atretic ear and multiple congenital anomalies. Using G-banding, fluorescent in situ hybridization (FISH), P1 artificial chromosome FISH and high-resolution comparative genomic hybridization (CGH), the marker was demonstrated to be a derivative chromosome resulting from malsegregation of a paternal 8;22 translocation: 47,XY, +der(22)t(8;22)(q24.1; q11.2). This case is noteworthy because the marker, while sharing similarities to der(22) in the Cat Eye syndrome (CES), also contains chromosome 8q material. This partial 8q trisomy confounds the diagnosis of CES associated with pure trisomy or pure tetrasomy 22q. The paternal translocation is noted with prolonged infertility and oligospermia, which again highlights the utility and necessity of chromosome analysis in this setting.

Abnormalities, Multiple↗
PubMed1990

Sex-chromosome segregation in inbred Drosophila melanogaster XXY females. I. Influence of closely related Y chromosome derivatives.

In tests of XXYder hybrids from two inbred lines of Drosophila melanogaster, a non-random distribution of various Yder chromosomes was found at regular X disjunction. This non-random Yder distribution was dependent on differences within the proximal X chromosome region (forked--centromere) of these particular lines, with a limited influence of the Yder,s. The Yder,s (originating from BsYy+ chromosome) showed a large influence on both level and brood pattern of secondary non-disjunction. There was no correlation between secondary non-disjunction and non-random Yder distribution, indicating different mechanisms. Cytological examination of the five Yder chromosomes disclosed no relation between the composition or configuration of the Yder,s and the observed distribution effects. Various parts of the present results show inconsistencies with either of the two existing segregation models (Grell, Novitski), suggesting that the mechanistic understanding of the meiotic process requires additional assumptions and/or alternatives.

Animals↗
PubMed2007

Frequency of Y chromosome microdeletions and chromosomal abnormalities in infertile Thai men with oligozoospermia and azoospermia.

AIM: To investigate the possible causes of oligozoospermia and azoospermia in infertile Thai men, and to find the frequencies of Y chromosome microdeletions and cytogenetic abnormalities in this group. METHODS: From June 2003 to November 2005, 50 azoospermic and 80 oligozoospermic men were enrolled in the study. A detailed history was taken for each man, followed by general and genital examinations. Y chromosome microdeletions were detected by multiplex polymerase chain reaction (PCR) using 11 gene-specific primers that covered all three regions of the azoospermic factor (AZFa, AZFb and AZFc). Fifty men with normal semen analysis were also studied. Karyotyping was done with the standard G- and Q-banding. Serum concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL) and testosterone were measured by electrochemiluminescence immunoassays (ECLIA). RESULTS: Azoospermia and oligozoospermia could be explained by previous orchitis in 22.3%, former bilateral cryptorchidism in 19.2%, abnormal karyotypes in 4.6% and Y chromosome microdeletions in 3.8% of the subjects. The most frequent deletions were in the AZFc region (50%), followed by AZFb (33%) and AZFbc (17%). No significant difference was detected in hormonal profiles of infertile men, with or without microdeletions. CONCLUSION: The frequencies of Y chromosome microdeletions and cytogenetic abnormalities in oligozoospermic and azoospermic Thai men are comparable with similarly infertile men from other Asian and Western countries.

Azoospermia↗
PubMed2003

Chromosomal speciation and molecular divergence--accelerated evolution in rearranged chromosomes.

Humans and their closest evolutionary relatives, the chimpanzees, differ in approximately 1.24% of their genomic DNA sequences. The fraction of these changes accumulated during the speciation processes that have separated the two lineages may be of special relevance in understanding the basis of their differences. We analyzed human and chimpanzee sequence data to search for the patterns of divergence and polymorphism predicted by a theoretical model of speciation. According to the model, positively selected changes should accumulate in chromosomes that present fixed structural differences, such as inversions, between the two species. Protein evolution was more than 2.2 times faster in chromosomes that had undergone structural rearrangements compared with colinear chromosomes. Also, nucleotide variability is slightly lower in rearranged chromosomes. These patterns of divergence and polymorphism may be, at least in part, the molecular footprint of speciation events in the human and chimpanzee lineages.

Alleles↗
PubMed1984

Cloning of the chromosome breakpoint of neoplastic B cells with the t(14;18) chromosome translocation.

From an acute B-cell leukemia cell line, a DNA probe was obtained that was specific for chromosome 18 and flanked the heavy chain joining region of the immunoglobulin heavy chain locus on chromosome 14. This probe detected rearrangement of the homologous DNA segment in the leukemic cells and in follicular lymphoma cells with the t(14:18) chromosome translocation but not in other neoplastic or normal B or T cells. The probe appears to identify bcl-2, a gene locus on chromosome 18 (band q21) that is unrelated to known oncogenes and may be important in the pathogenesis of B-cell neoplasms with this translocation.

Animals↗
PubMed2000

Replication delay along FRA7H, a common fragile site on human chromosome 7, leads to chromosomal instability.

Common fragile sites are specific chromosomal loci that show gaps, breaks, or rearrangements in metaphase chromosomes under conditions that interfere with DNA replication. The mechanism underlying the chromosomal instability at fragile sites was hypothesized to associate with late replication time. Here, we aimed to investigate the replication pattern of the common fragile site FRA7H, encompassing 160 kb on the long arm of human chromosome 7. Using in situ hybridization on interphase nuclei, we revealed that the replication of this region is initiated relatively early, before 30% of S phase is completed. However, a high fraction ( approximately 35%) of S-phase nuclei showed allelic asynchrony, indicating that the replication of FRA7H is accomplished at different times in S phase. This allelic asynchrony is not the result of a specific replication time of each FRA7H allele. Analysis of the replication pattern of adjacent clones along FRA7H by using cell population and two-color fluorescent in situ hybridization analyses showed significant differences in the replication of adjacent clones, under normal growth condition and upon aphidicolin treatment. This pattern significantly differed from that of two nonfragile regions which showed a coordinated replication under both conditions. These results indicate that aphidicolin is enhancing an already existing difference in the replication time along the FRA7H region. Based on our replication analysis of FRA7H and on previous analysis of the common fragile site FRA3B, we suggest that delayed replication is underlying the fragility at aphidicolin-induced common fragile sites.

Cell Line↗
PubMed1999

Comparative mapping between human chromosome 3 and porcine chromosome 13.

Zoo-FISH and somatic cell hybrid panels have earlier demonstrated extended synteny conservation between human chromosome 3 (HSA3) and pig chromosome 13 (SSC13). In the present study, eight human genes viz., ADCY5, CASR, COL7A1, COL8A1, ITIH1, RHO, SIAT1 and XPC, spread along the length of HSA3, were chosen for expanding the comparative map between the two chromosomes. Using human and rat cDNAs, or human- and porcine-specific PCR products as probes, 8 porcine lambda clones were isolated. After subcloning and partial sequence determination, identity of the clones with regards to the specific genes was established. The eight type 1 markers thus obtained were biotin labeled and FISH mapped to pig metaphase spreads. All lambda clones localized to SSC13. In combination with the hitherto published mapping data of coding sequences on SSC13, a preliminary comparative status depicting the relative organization of this chromosome with respect to HSA3 was developed. The comparative map thus obtained bears significance in searching for candidate genes of economically important traits mapped to SSC13.

Adenylyl Cyclases↗
PubMed2000

Conserved synteny between the chicken Z sex chromosome and human chromosome 9 includes the male regulatory gene DMRT1: a comparative (re)view on avian sex determination.

Sex-determination mechanisms in birds and mammals evolved independently for more than 300 million years. Unlike mammals, sex determination in birds operates through a ZZ/ZW sex chromosome system, in which the female is the heterogametic sex. However, the molecular mechanism remains to be elucidated. Comparative gene mapping revealed that several genes on human chromosome 9 (HSA 9) have homologs on the chicken Z chromosome (GGA Z), indicating the common ancestry of large parts of GGA Z and HSA 9. Based on chromosome homology maps, we isolated a Z-linked chicken ortholog of DMRT1, which has been implicated in XY sex reversal in humans. Its location on the avian Z and within the sex-reversal region on HSA 9p suggests that DMRT1 represents an ancestral dosage-sensitive gene for vertebrate sex-determination. Z dosage may be crucial for male sexual differentiation/determination in birds.

Amino Acid Sequence↗
PubMed1977

Regional assignment of seven genes on chromosome 1 of man by use of man-Chinese hamster somatic cell hybrids. I. Results obtained after hybridization of human cells carrying reciprocal translocations involving chromosome 1.

Regional localization studies of genes coding for human PGD, PPH1, PGM1, UGPP, GuK1, Pep-C, and FH, which have been assigned to chromosome 1, were performed with man-Chinese hamster somatic cell hybrids, Informative hybrids that retained fragments of the human chromosome 1 were produced by fusion of hamster cells with human cells carrying reciprocal translocations involving chromosome 1. Analysis of the hybrids that retained one of the translocation chromosomes or de novo rearrangements involving the human 1 revealed the following gene positions: PGD and PPH1 in 1pter leads to 1p32, PGM1 in 1p32 leads to 1p22, UGPP and GuK1 in 1q21 leads to 1q42, FH in 1qter leads to 1q42, and Pep-C probably in 1q42.

Animals↗
PubMed1985

Chromosomal evolution in Malagasy lemurs. VIII. Chromosome banding studies of Lepilemur ruficaudatus, L leucopus, and L septentrionalis.

The karyotypes of three Lepilemuridae species, Lepilemur ruficaudatus, L leucopus, and L septentrionalis, are described and compared. An almost complete analogy of chromosome banding is exhibited. Several complex chromosomal rearrangements, especially end-to-end translocations, have occurred in the evolution of these species. The chromosomal data indicate that the species studied are well separated. In addition, their common chromosomal characters show that they constitute a clearly distinct family among the lemurs.

Animals↗
PubMed1991

Interphase cytogenetics reveals somatic pairing of chromosome 17 centromeres in normal human brain tissue, but no trisomy 7 or sex-chromosome loss.

Nuclei isolated from normal human brain tissue, collected from six autopsies, were hybridized with a panel of nine satellite DNA probes specific for the centromeric regions of chromosomes 1, 6, 7, 10, 11, 17, 18, and the X and Y chromosomes. The results did not confirm the recently reported trisomy 7 and loss of sex chromosomes observed in metaphases obtained from normal brain tissue after short-term cultures; however, cells of all six brains displayed somatic pairing of the chromosome 17 centromeres in approximately 50% of the nuclei.

Brain↗
PubMed1995

Meiotic segregation of the X and Y chromosomes and chromosome 1 analyzed by three-color FISH in human interphase spermatozoa.

Meiotic segregation of the X and Y chromosomes and chromosome 1 was analyzed by three-color fluorescence in situ hybridization (FISH) in 94,575 human interphase spermatozoa from four control subjects. More than 99% of the sperm cells were labeled. The proportions of X- and Y-bearing sperm were estimated to be 49.83% and 48.30%, respectively. The disomy rates were 0.04%, 0.009%, and 0.20% for the X and Y chromosomes and chromosome 1, respectively. Hyperhaploidy with an extra gonosome was found in 0.34% of spermatozoa, due to nondisjunction during meiosis I. The frequency of diploidy was 0.11% at meiosis I and 0.036% at meiosis II. Cohybridization of one autosomal and two gonosomal probes, in three-color FISH in interphase spermatozoa, seems to accurately discriminate diploidies from disomies, as well as the meiotic origin of gonosomal aneuploidies in sperm cells.

DNA Probes↗
PubMed1991

Missing Y chromosome in Ph1-negative chronic myeloid leukemia with bcr rearrangement. Evidence for a bcr-abl recombination on chromosome 22 by in situ hybridization.

In a case of Philadelphia chromosome (Ph1)-negative chronic myeloid leukemia (CML) without the Y chromosome, we investigated the differences, at the molecular level, from Ph1-positive CML. Using Southern blot analysis and in situ hybridization studies, we could demonstrate a rearrangement within the breakpoint cluster region (bcr), and the location of a bcr-abl fusion gene on chromosome 22. To our knowledge, this is the first case of Ph1-negative CML with a loss of the Y chromosome in which the molecular abnormalities are shown to be identical with those in Ph1-positive CML.

Chromosome Aberrations↗
PubMed2003

Genome-wide and fine-mapping linkage studies of type 2 diabetes and glucose traits in the Old Order Amish: evidence for a new diabetes locus on chromosome 14q11 and confirmation of a locus on chromosome 1q21-q24.

We conducted a genome scan using a 10-cM map to search for genes linked to type 2 diabetes in 691 individuals from a founder population, the Old Order Amish. We then saturated two regions on chromosomes 1 and 14 showing promising linkage signals with additional markers to produce a approximately 2-cM map for fine mapping. Analyses of both discrete traits (type 2 diabetes and the composite trait of type 2 diabetes and/or impaired glucose homeostasis [IGH]), and quantitative traits (glucose levels during a 75-g oral glucose challenge, designated glucose 0-180 and HbA(1c)) were performed. We obtained significant evidence for linkage to type 2 diabetes in a novel region on chromosome 14q11 (logarithm of odds [LOD] for diabetes = 3.48, P = 0.00005). Furthermore, we observed evidence for the existence of a diabetes-related locus on chromosome 1q21-q24 (LOD for type 2 diabetes/IGH = 2.35, P = 0.0008), a region shown to be linked to diabetes in several other studies. Suggestive evidence for linkage to glucose traits was observed on three other regions: 14q11-q13 (telomeric to that above with LOD = 1.82-1.85 for glucose 150 and 180), 1p31 (LOD = 1.28-2.30 for type 2 diabetes and glucose 120-180), and 18p (LOD = 3.07, P = 0.000085 for HbA(1c) and LOD = 1.50 for glucose 0). In conclusion, our findings provide evidence that type 2 diabetes susceptibility genes reside on chromosomes 1, 14, and 18.

Blood Glucose↗
PubMed1999

Prenatal diagnosis of supernumerary marker 15 chromosomes and exclusion of uniparental disomy for chromosome 15.

Supernumerary marker chromosomes (SMC) were identified in amniocytes from two unrelated fetuses. Fluorescence in situ hybridization (FISH) characterization of the SMC showed they were derived from chromosome 15; SMC(15). Parental karyotyping demonstrated the SMC(15) to be de novo in one fetus and paternally derived in the other. Previous reports showed that the presence or absence of the Prader-Willi/Angelman syndrome (PWS/AS) critical region, loci D15S11 and distal, in a SMC(15) was associated with an abnormal or normal phenotype, respectively. FISH analysis demonstrated both SMC(15) lacked the D15S11 locus. Because SMC(15) were found at an increased incidence in patients with PWS/AS, we performed methylation analysis at the SNRPN locus to exclude a deletion or uniparental disomy (UPD) of chromosome 15. Both probands showed biparental inheritance at this locus. Based on the FISH and molecular analyses, both fetuses were predicted to have a normal phenotype. The pregnancies were continued and both probands are phenotypically and developmentally normal. These cases illustrate the importance of a combination of family studies, FISH characterization and molecular analyses in SMC(15) identified prenatally. In particular, any chromosome 15 rearrangement identified at prenatal diagnosis should be considered a candidate for UPD15 studies.

Adult↗
PubMed2002

Molecular cloning and characterization of ST7R (ST7-like, ST7L) on human chromosome 1p13, a novel gene homologous to tumor suppressor gene ST7 on human chromosome 7q31.

ST7 is a tumor suppressor gene, which is clustered with WNT2 gene in human chromosome 7q31 region. WNT2 gene is homologous to WNT2B gene. WNT2B gene encodes two isoforms due to alternative splicing of alternative promoter type. WNT2 and WNT2B isoform 2 (WNT2B2) are positive regulators of the WNT - beta-catenin - TCF signaling pathway. Here, a novel ST7-related gene ST7R (ST7-like, ST7L) was identified by using bioinformatics, and ST7R cDNAs were isolated by using cDNA-PCR. ST7R gene encoded 575-amino-acid polypeptide with leucine zipper domain and 3 tyrosine-phosphorylation sites. Human ST7R was homologous to human ST7 (72.1% total-amino-acid identity) and Drosophila CG3634 (56.8% total-amino-acid identity). Leucine zipper domain was unique to ST7R. Tyr 268 and Tyr 441 of ST7R were conserved in ST7 and CG3634. ST7R-homologous domains (S7H1, S7H2, and S7H3) were conserved among ST7R, ST7, and CG3634. ST7R gene consisted of at least 15 exons, and four ST7R isoforms were transcribed due to alternative splicing. ST7R and WNT2B genes, located in human chromosome 1p13 region, were clustered in tail-to-tail manner with an interval of less than 5.0-kb. ST7R-WNT2B and ST7-WNT2 gene clusters might be generated due to duplication of an ancestral gene cluster. Because allelic loss or rearrangements of human chromosome 1p13 region are reported in breast cancer, germ cell tumors, squamous cell carcinoma of head and neck, non-small cell lung cancer, gastrointestinal stromal/smooth muscle tumors (GIST), meningioma, melanoma, acute megakaryoblastic leukemia (M7), and Kaposi's sarcoma, ST7R might be a novel tumor suppressor gene on human chromosome 1p13.

Alternative Splicing↗
PubMed1992

[Use of a chromosome 21 gene library in the identification of a marker chromosome in chronic myeloid leukemia].

The non-isotopic in situ hybridization makes it possible the analysis of, both, numeric and structural chromosome aberrations in interphase nuclei. Moreover, this technique is useful for identification of chromosome markers of unknown origin, frequently present in malignant diseases. In our case, the fluorescent in situ hybridization allowed us, in a CML patient in accelerated phase, to know the origin of a chromosome marker, and then, to state that the patient had a 21 trisomy added to the Philadelphia chromosome.

Blast Crisis↗