RESUMO
We have mapped the autosomal sex reversal locus, SRA1, associated with campomelic dysplasia (CMPD1) to 17q24.3-q25.1 by three independent apparently balanced de novo reciprocal translocations. Chromosome painting indicates that the translocated segment of 17q involves about 15% of chromosome 17 in all three translocations, corresponding to a breakpoint at the interphase between 17q24-q25. All three 17q breakpoints were localized distal to the growth hormone locus (GH), and proximal to thymidine kinase (TK1). Due to the distal location of the breakpoints, previously mentioned candidate genes, HOX2 and COL1A1, can be excluded as being involved in CMPD1/SRA1. The mouse mutant tail-short (Ts) which maps to the homologous syntenic region on mouse chromosome 11, displays some of the features of CMPD1.
Assuntos
Anormalidades Múltiplas/genética , Doenças do Desenvolvimento Ósseo/genética , Aberrações Cromossômicas/genética , Cromossomos Humanos Par 13/ultraestrutura , Cromossomos Humanos Par 17/ultraestrutura , Cromossomos Humanos Par 1/ultraestrutura , Cromossomos Humanos Par 7/ultraestrutura , Transtornos do Desenvolvimento Sexual , Disgenesia Gonadal/genética , Análise para Determinação do Sexo , Translocação Genética , Adulto , Sequência de Bases , Transtornos Cromossômicos , Mapeamento Cromossômico , Feminino , Marcadores Genéticos , Humanos , Hibridização in Situ Fluorescente , Recém-Nascido , Masculino , Dados de Sequência Molecular , Fenótipo , Reação em Cadeia da PolimeraseRESUMO
A reliable technique for staining human chromosomal nucleolar organizers (NOR's) with silver solutions is described. The NOR's can be selectively stained dark brown by silver solutions leaving the chromosome arms unstained and available for counterstaining with orcein or Giemsa dyes. Unequivocal identification of chromosome pairs bearing NOR's can be achieved using fluorescent banding techniques followed by silver staining. The silver staining procedure for NOR's was simplified and standardized through control of the chemical and physical conditions during silver impregnation and developing.
Assuntos
Cromossomos/ultraestrutura , DNA/análise , RNA Ribossômico/biossíntese , Humanos , Métodos , Nitrato de Prata , Coloração e RotulagemRESUMO
A simple ammoniacal silver staining procedure, designated Ag-AS, differentially stains the chromosomal locations of ribosomal DNA in certain mammalian species. This was critically demonstrated by Ag-AS staining of the nucleolus organizer regions in karyotypes of the same species and cell lines used for locating the ribosomal cistrons by DNA/RNA in situ hybridization. With Ag-AS, silver stained NORs (Ag-NORs) are visualized as black spherical bodies on yellow-brown chromosome arms. Ag-NORs were visualized throughout mitosis at the secondary constrictions in the rat kangaroo, Seba's fruit bat, Indian muntjac, and Rhesus monkey. The Chinese hamster and cattle have telomeric Ag-NORs, the mouse subcentromeric Ag-NORs, and the field vole Ag-NORs as minute short arms or choromosomal satellites. Ag-NORs occur at both secondary constrictions and at telomeres in the cotton rat. Variability in Ag-NOR pattern included differences in the number of Ag-NORs per cell within a cell population, size of Ag-NORs among chromosomes of a complement, and presence of Ag-NOR on particular chromosomes in two cell lines of the Chinese hamster. The available cytochemical data suggest that the Ag-AS reaction stains chromosomal proteins at the NOR rather than the rDNA itself.
Assuntos
Mapeamento Cromossômico , Cromossomos/ultraestrutura , Genes , Animais , Arvicolinae , Quirópteros , Cromossomos/metabolismo , Cricetinae , Cervos , Feminino , Haplorrinos , Cariotipagem , Macaca mulatta , Macropodidae , Masculino , Camundongos , Mitose , Nucleoproteínas/análise , RNA Ribossômico/biossíntese , Ratos , Prata , Coloração e RotulagemRESUMO
Haploid karyotypes composed of 5 metacentrics (T. umbilicatus, T. koebelei), 4 metacentrics plus 2 telocentrics (T. tubicola), 5 metacentrics plus 1 telocentric (T. warreni), 5 metacentrics plus 1 acrocentric (T. baccharidis, T. vesiculi, T. occidentalis, T. capillaceus), and 6 metacentrics (T. californicus) are described. Five metacentrics are postulated as ancestral for the Torymidae, based on karyotype frequency for the family and Robertsonian relationships among taxa. Karyotypes of 5 metacentrics plus 1 telocentric are considered ancestral for the genus Torymus. Derived karyotypes have apparently evolved independently in several lineages within the genus.
Assuntos
Himenópteros , Cariotipagem , Especificidade da Espécie , Animais , Cromossomos , HaploidiaRESUMO
A permanent tissue-cultured cell line (designated OK) has been established from kidney tissue of an adult American opossum. The OK line has been characterized with respect to morphology, chromosome constitution, tissue-culture requirements, and attainable mitotic arrest. The cells are epithelial-like with a stable nondiploid chromosomal modal number of 23. Cells grown in Eagle's minimal essential medium with 10% fetal bovine serum have a mean doubling time of 18 hr. The cell line OK is potentially useful for the isolation and purification of the mammalian X chromosome because of the size differential between the smaller X's and the larger autosomes.
Assuntos
Linhagem Celular , Animais , Cromossomos/análise , Colchicina/farmacologia , Meios de Cultura , Desmossomos/ultraestrutura , Epitélio/ultraestrutura , Feminino , Cariotipagem , Rim , Mitose/efeitos dos fármacos , Gambás , Cromossomo XRESUMO
A silver-staining technique specific for demonstrating nucleolus organizer regions (NOR) showed that the achromatic stalks of the 10 acrocentric autosomes of the human complement represent the NORs. Some variability in number of stained stalks is observed from cell-to-cell and from individual-to-individual. The silver-stained masses may extend beyond the stalks and cover the satellites, especially in chromosomes with short stalks or minute satellites.