The gene (NFE2L1) for human NRF-1, an activator involved in nuclear-mitochondrial interactions, maps to 7q32.
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Animals↗
Biomedical subjects
M Rocchi
Publications and source records attributed to M Rocchi.
Comparative mapping of human alphoid sequences in great apes using fluorescence in situ hybridization.
Twenty-seven human alphoid DNA probes have been hybridized in situ to metaphase spreads of the common chimpanzee (PTR), the pigmy chimpanzee (PPA), and the gorilla (GGO) to investigate the evolutionary relationship between the centromeric regions of the great ape chromosomes. The surprising results showed that the vast majority of the probes did not recognize their corresponding homologous chromosomes. Alphoid sequences belonging to the suprachromosomal family 1 (chromosomes 1, 3, 5, 6, 7, 10, 12, 16, and 19) yielded very heterogeneous results: some probes gave intense signals, but always on nonhomologous chromosomes; others did not produce any hybridization signal. Almost all probes belonging to the suprachromosomal family 2 (chromosomes 2, 4, 8, 9, 13, 14, 15, 18, 20, 21, and 22) recognized a single chromosome: chromosome 11 (phylogenetic IX) in PTR and PPA and chromosome 19 (phylogenetic V) in GGO. Localization of probes of suprachromosomal family 3 (chromosomes 1, 11, 17, and X) was found to be substantially conserved in PTR and PPA, but not in GGO. Probe pDMX1, specific for the human X chromosome, was the only sequence detecting its corresponding chromosome in all three species. PPA chromosomes I, IIp, IIq, IV, V, VI, and XVIII were never labeled, even under low-stringency hybridization conditions, by the 27 alphoid probes used in this study. These results, with particular reference to differences found in the two related species PTR and PPA, suggest that alphoid centromeric sequences underwent a very rapid evolution.
Animals↗
Chromosomal localization of mitochondrial transcription factor A (TCF6), single-stranded DNA-binding protein (SSBP), and endonuclease G (ENDOG), three human housekeeping genes involved in mitochondrial biogenesis.
By using a PCR-based screening of a somatic cell hybrid panel and FISH, we have assigned the loci of mitochondrial single-stranded DNA-binding protein (SSBP), mitochondrial transcription factor A (TCF6), and mitochondrial endonuclease G (ENDOG) genes to human chromosomes 7q34, 10q21, and 9q34.1, respectively. The products of these three genes are involved in fundamental aspects of mitochondrial biogenesis, such as replication and transcription of the mitochondrial genome. The chromosomal localization of these genes is important to testing whether the corresponding proteins may play a role in the etiopathogenesis of human disorders associated with qualitative or quantitative abnormalities of mitochondrial DNA.
Chromosome Mapping↗
Analysis of GC-rich repetitive nucleotide sequences in great apes.
The genomes of four primate species, belonging to the families Pongidae (chimpanzee, gorilla, and orangutan) and Hylobatidae (gibbons), have been analyzed for the presence and organization of two human GC-rich heterochromatic repetitive sequences: beta Satellite (beta Sat) and LongSau (LSau) repeats. By Southern blot hybridization and PCR, both families of repeats were detected in all the analyzed species, thus indicating their origin in an ape ancestor. In the chimpanzee and gorilla, as in man, beta Sat sequences showed a 68-bp Sau3A periodicity and were preferentially organized in large clusters, whereas in the orangutan, they were organized in DNA fragments of 550 bp, which did not seem to be characterized by a tandem organization. On the contrary, in each of the analyzed species, the bulk of LSau sequences showed a longer Sau3A periodicity than that observed in man (450-550 bp). Furthermore, only in the chimpanzee genome some of LSau repeats seemed to be interspersed within blocks of beta Sat sequences. This sequence organization, which also characterizes the human genome, is probably absent in the gorilla. In fact, the analysis of a gorilla genomic library suggested that LSau repeats are not preferentially in linkage with beta Sat sequences. Moreover, LSau sequences were found in a genomic sector characterized by the simultaneous presence of L1 and (CA) repeats, as well as of anonymous sequences and known genes. In spite of the different sequence organization, the nucleotide differences between complete human and gorilla LSau repeats were very few, whereas one gorilla LSau repeat, interrupted by a probably-truncated L1 transposon, showed a higher degree of divergence.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Ordered mapping of three alpha satellite DNA subsets on human chromosome 22.
We report the physical order of three alphoid DNA subsets on human chromosome 22 determined by a combination of low- and high-resolution cytological mapping. Multicolor fluorescence in situ hybridization was performed on metaphase chromosomes, interphase nuclei and extended chromatin preparations. The results visually demonstrate the presence of three distinct alphoid DNA domains at the centromeric region of chromosome 22. Two domains appear adjacent by extended chromatin hybridization, while the third one is separated by DNA that does not hybridize with any of our probes. Our data demonstrate the applicability of interphase mapping for ordering alpha satellite DNA repeat arrays. However, in our experiments, the relationship between the extremities of repeat arrays could only be studied by extended chromatin experiments.
Chromosome Mapping↗
Molecular diagnosis of hereditary neuropathy with liability to pressure palsies (HNPP) by detection of 17p11.2 deletion in Italian patients.
Hereditary neuropathy with a liability to pressure palsies (HNPP) is an autosomal dominant disorder characterized by recurrent pressure palsies generally precipitated by minor trauma; weakness and paraesthesia usually improve and recover completely in a few months. By Southern blotting and fluorescent in situ hybridization analysis we confirm the presence of a 17p11.2 deletion in familial and in isolated cases of HNPP, suggesting that molecular analysis of the 17p11.2 region could also be a reliable and non-invasive method of diagnosis in sporadic cases, where a correct diagnosis usually requires a nerve biopsy. Although HNPP is a mild disease and not all patients seek medical attention, a presymptomatic diagnosis is useful for assessing the risk during genetic counselling, due to the inheritance of the mutation.
Chromosome Deletion↗
Expression and quantification of IgG and IgM molecules on the surface of lymphocytes of cattle infected with bovine leukaemia virus.
Immunogold-labelled antibodies were used with scanning electron microscopy (SEM) and fluorescent-labelled antibodies were used with flow cytometry (FACS) to evaluate the expression and quantity of IgG and IgM molecules on the surface of the lymphocytes of cattle infected with bovine leukaemia virus (BLV). The BLV-infected animals were divided serologically and haematologically into groups with (BLV+PL+) and without (BLV+PL-) persistent lymphocytosis (PL). The percentage of IgM-bearing cells was significantly higher in the BLV+PL+ group than in the BLV-PL- and BLV+PL- groups by FACS. There was a significantly higher percentage of IgG-bearing cells in the BLV+PL+ group than in the BLV-PL- and BLV+PL- groups by SEM, but no differences were found by FACS. A significantly higher intensity of IgM expression was observed in the BLV+PL+ group by SEM. A higher intensity of IgG expression in some animals was detected only by SEM. An increase in the number of larger IgM cells were observed in the BLV+PL- and BLV+PL+ groups by SEM. The SEM analysis was more sensitive than FACS in this experiment.
Animals↗
A panel of subchromosomal painting libraries representing over 300 regions of the human genome.
DNA samples from about 100 human-hamster somatic cell hybrids, previously characterized by conventional banding techniques, were amplified with dual-Alu PCR. The products were then used as probes in FISH experiments on normal human metaphases for an accurate cytogenetic characterization of the human material retained in each hybrid. In addition to entire chromosomes, most hybrids were found to contain one or a few chromosome fragments, as a result of rearrangements that had occurred in vitro. Forty additional primary hybrids, in which conventional cytogenetic analysis failed to reveal any complete human chromosome, contained many human chromosome fragments. More than 300 chromosome fragments were scored and their precise chromosomal location recorded. We show data indicating that subchromosomal painting libraries generated from these hybrids can be favorably used in the fine characterization of chromosomal rearrangements encountered in clinical cytogenetics or in tumor cytogenetics, and in tracking chromosomal changes that occurred in primate evolution.
Animals↗
The genes encoding the glutamate receptor subunits KA1 and KA2 (GRIK4 and GRIK5) are located on separate chromosomes in human, mouse, and rat.
The chromosomal localization of the human and rat genes encoding the kainate-preferring glutamate receptor subunits KA1 and KA2 (GRIK4 and GRIK5, respectively) was determined by Southern analysis of rat x mouse and human x mouse somatic cell hybrid panels and by fluorescence in situ hybridization. The localization of the mouse genes (Grik4 and Grik5) was established by interspecific backcross mapping. GRIK4 and GRIK5 are located on separate chromosomes (Chrs) in all species. GRIK4 mapped to human Chr 11q22.3, mouse Chr 9, and rat Chr 8. GRIK5 mapped to human Chr 19q13.2, mouse Chr 7, and rat Chr 1. The genes encoding the (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-preferring subunit GluR4, or GluRD (GRIA4), the neural cell adhesion molecule (NCAM), the D2 dopamine receptor (DRD2), and the Thy-1 cell surface antigen (THY1) have all been previously mapped to the human Chr 11q22 region. The mapping of the human GRIK4 and GRIK5 genes confirms and extends the relationship between human Chr 11 and mouse Chr 9 and also human Chr 19 and mouse Chr 7. GRIK4 is the fifth gene shared by human Chr 11 and rat Chr 8, whereas GRIK5 is 1 out of the 12 genes that are located on both human Chr 19 and rat Chr 1. Our data extend the conserved synteny established between certain human, mouse, and rat Chrs.
Animals↗
The generation of monoclonal antibodies recognising novel epitopes by immunisation with solid matrix antigen-antibody complexes reveals a polymorphic determinant on feline CD4.
Monoclonal antibodies were generated against the feline homologue of CD4 (fCD4) by immunisation of mice with solid matrix antigen-antibody complexes of monoclonal antibody Fel7 (anti-fCD4) and formalin-fixed Staphylococcus A (SMAA-fCD4). The resulting fusion produced nine monoclonal antibodies each of which recognised a major population of feline lymphocytes and which immunoprecipitated a 55 kDa ligand from the feline T lymphosarcoma cell line 3201. Epitope mapping of the antibodies against soluble fCD4 by surface plasmon resonance indicated that the antibodies recognised five separate epitopes distinct from that defined by the Fel7 antibody used to prepare the SMAA-fCD4. These data demonstrate that SMAA complexes are an efficient means of generating monoclonal antibodies recognising novel epitopes on an antigen. One monoclonal antibody (vpg39) recognised an epitope that was expressed variably between cats, being either present or completely absent. Analysis of peripheral blood lymphocytes from specific pathogen free cats suggested that failure to react with the vpg39 antibody was an inherited trait.
Animals↗
Heterogeneous chromosomal aberrations generate 3' truncations of the NFKB2/lyt-10 gene in lymphoid malignancies.
The NFKB2(lyt-10) gene codes for a protein that is a member of the NK-kappa B/rel family of transcription factors containing a DNA-binding rel domain and a carboxy-terminal ankyrin-like domain. The NFKB2 gene represents a candidate proto-oncogene, since it has been found to be involved in a chromosomal translocation t(10;14)(q24;q32) in one case of B-cell lymphoma and in gene rearrangements in various types of lymphoid malignancies. To elucidate the structural and functional consequences of NFKB2 rearrangements, we report the molecular characterization of three novel rearranged NFKB2 genes in lymphoid tumors. In one case of multiple myeloma (MM), cloning and sequencing analysis of reciprocal breakpoint sites showed that they occurred within intron 15 of the NFKB2 gene and led to the complete deletion of the 3' portion of the gene coding for the ankyrin domain. Fluorescent in situ hybridization (FISH) analysis showed that the novel regions involved in the NFKB2 rearrangement originated from chromosome 7q34, thus implying the occurrence of a t(7;10)(q34;q24) reciprocal chromosomal translocation. In one case of T-cell cutaneous lymphoma (CTCL) and in one of B-cell chronic lymphocytic leukemia (B-CLL), NFKB2 rearrangements occurred, respectively, within exons 18 and 20 of the gene and involved recombinations with distinct regions of chromosome 10q24. Molecular analysis suggested that these rearrangements may occur as a consequence of small internal chromosomal deletions. In both of these cases, the rearrangements led to specific carboxy-terminal truncations of NFKB2 generating abnormal transcripts that coded for proteins lacking portions of the ankyrin domain. These proteins localize in the nucleus, suggesting their constitutive activation in vivo. Overall, our results indicate that NFKB2 rearrangements in lymphoid neoplasia may occur by heterogeneous mechanisms, including internal chromosomal deletion or chromosomal translocation. The common consequence of these rearrangements appears to be the deletion of 3' sequences of NFKB2 leading to the production of carboxy-truncated constitutively nuclear proteins that may be involved in tumorigenesis.
Amino Acid Sequence↗
A DNA fragment from Xq21 replaces a deleted region containing the entire FVIII gene in a severe hemophilia A patient.
In this paper we report the molecular characterization of a large deletion that removes the entire Factor VIII gene in a severe hemophilia A patient. Accurate DNA analysis of the breakpoint region revealed that a large DNA fragment replaced the 300-kb one, which was removed by the deletion. Pulsed-field gel electrophoresis analysis revealed that the size of the inserted fragment is about 550 kb. In situ hybridization demonstrated that part of the inserted region normally maps to Xq21 and to the tip of the short arm of the Y chromosome (Yp). In our patient this locus is present both in Xq21 and in Xq28, in addition to the Yp, being thus duplicated in the X chromosome. Sequence analysis of the 3' breakpoint suggested that an illegitimate recombination is probably the cause of this complex rearrangement.
Adult↗
Mapping of the human NMDAR2B receptor subunit gene (GRIN2B) to chromosome 12p12.
The N-methyl-D-aspartate (NMDA) receptor channel is essential for synaptic transmission and synaptic plasticity underlying memory, learning, and development. Three subunits of the NMDA receptor channel, NMDAR2A, NMDAR2B, and NMDAR2C (NR2A, NR2B, and NR2C), previously identified in mouse by cDNA cloning and expression, share a high level of homology, although their patterns of expression within the brain may differ. In the present work we report the localization of the gene encoding the human NMDAR2B receptor subunit (called GRIN2B for glutamate receptor, ionotropic, N-methyl-D-aspartate 2B) to chromosome 12p12 by in situ hybridization and somatic cell hybrids.
Animals↗
Assignment of the gene encoding the beta-subunit of the electron-transfer flavoprotein (ETFB) to human chromosome 19q13.3.
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Animals↗
Hereditary motor and sensory neuropathy with calf hypertrophy is associated with 17p11.2 duplication.
The demyelinating type of hereditary motor and sensory neuropathy (HMSN I) is characterized by progressive weakness and atrophy of leg muscles. Six patients (age, 25-79 yr) belonging to three generations had calf hypertrophy (6 of 6), foot drop or difficulty with heel walking (4 of 6), pes cavus (3 of 6), absent or depressed tendon jerks in the lower limbs (4 of 6), and mild distal sensory loss (3 of 6). No other family member had leg atrophy. Motor conduction velocities ranged from 20 to 40 m/sec. Sural nerve biopsy showed loss of large myelinated fibers, numerous onion bulbs, and segmental demyelination and remyelination. Computed tomographic scans of leg muscles and histological and morphometric findings in gastrocnemius revealed true muscular hypertrophy. Southern blot and fluorescence in situ hybridization documented the duplication of the entire 17p11.2 segment associated with classical HMSN IA. The pathogenesis of muscle hypertrophy in our cases is unclear. Chronic leg muscle weakness and long-standing partial denervation might cause calf enlargement by a combination of compensatory "work-induced" and "stretch-induced" fiber hypertrophy. Alternatively, that all the affected family members presented calf hypertrophy might suggest the action of a genetic factor associated with the duplication at 17p11.2.
Adult↗
Molecular cloning, cDNA sequence, and chromosomal localization of the human phosphatidylinositol 3-kinase p110 alpha (PIK3CA) gene.
Phosphatidylinositol (PI) 3-kinase is a heterodimeric enzyme comprising a 110-kDa catalytic subunit and an 85-kDa regulatory subunit that binds to tyrosine phosphopeptide sites linked directly or indirectly to receptors serving diverse signal functions. Knowledge of the structure and function of PI 3-kinase was greatly advanced by the purification, cDNA cloning, and subsequent expression of the bovine enzyme. Here the cloning of the cDNA for the human p110 alpha subunit of PI 3-kinase (PIK3CA), encoding a protein 99% identical to the bovine p110, and of its gene in YAC is described. The chromosomal localization of the gene for PIK3CA is shown to be at 3q21-qter as determined using somatic cell hybrids. In situ hybridization performed using Alu-PCR from the YAC DNA located the gene in 3q26.3.
Animals↗
Characterization of chimpanzee-hamster hybrids by chromosome painting.
A panel of chimpanzee-human somatic cell hybrids was characterized by dual Alu-PCR of the chimpanzee DNA in the hybrid and subsequent hybridization of the labeled PCR products to human and chimpanzee chromosomes. In addition to the identification of the intact chimpanzee chromosomes retained in each hybrid, chromosome fragments were identified that will be useful in regional mapping. This technique also revealed the presence of centric inversions.
Animals↗
Cloning and comparative mapping of recently evolved human chromosome 22-specific alpha satellite DNA.
We have isolated and characterized a new alphoid probe, named p190.22. Its chromosomal location was investigated using fluorescence in situ hybridization. Under high stringency conditions p190.22 recognizes specifically the centromere of chromosome 22. A chromosome 22-specific alphoid subset has been previously reported in the literature (p22/1:2.1). The partial sequence and the genomic organization comparison strongly suggests that they recognize distinct subsets both specific for chromosome 22. The comparative mapping of probes p190.22 and p22/1:2.1 on chimpanzee (PTR and PPA) and gorilla (GGO) chromosomes was investigated. The two probes showed different hybridization results. p190.22, in particular, did not show any hybridization signal in these three species, suggesting a recent evolution.
Animals↗