RESUMO
Heterozygous carriers of HPRT1 mutations responsible for Lesch-Nyhan syndrome can be detected by analysis of somatic cell hybrids derived from peripheral blood lymphocytes and Hprt1-negative cells of rodent origin followed by selection in culture medium containing hypoxanthine, aminopterine, and thymidine (HAT). The parental origin of the X chromosome containing the normal HPRT1 allele in HPRT1(+) hybrid cell lines can be determined by molecular haplotyping attributable to highly polymorphic X-linked markers. We used this procedure to study a presumed carrier whose paternal active X chromosome always segregated in the cell hybrids derived from her. Conversely, her maternal X chromosome was systematically absent in most cell hybrids, or when present, it was inactive and coexisted with an active, paternal X chromosome. These results clearly demonstrated that the proband was a heterozygous carrier of a mutation responsible for HPRT1 deficiency.
Assuntos
Heterozigoto , Hipoxantina Fosforribosiltransferase/genética , Síndrome de Lesch-Nyhan/genética , Adulto , Animais , DNA/genética , Saúde da Família , Feminino , Triagem de Portadores Genéticos/métodos , Haplótipos , Humanos , Células Híbridas , Hipoxantina Fosforribosiltransferase/deficiência , Síndrome de Lesch-Nyhan/enzimologia , Síndrome de Lesch-Nyhan/patologia , Mutação , Cromossomo X/genéticaRESUMO
Comparative gene assignment between the spider monkey species Ateles paniscus chamek (APC) and man (HSA) showed conserved syntenic associations despite extensive karyotypic rearrangement between species. Two HSA 14q genes were allocated to APC 2q, being syntenic to other HSA 14q and HSA 15q markers previously assigned to APC 2q, and to HSA 12q genes previously assigned to APC 2p. These findings were consistent with A. geoffroyi chromosome painting with human whole-chromosome probes, indicating that the genus Ateles is karyotypically very rearranged. On the other hand, three human X-linked markers were assigned to the Ateles X chromosome, indicating that this chromosome is evolutionary stable.
Assuntos
Cebidae/genética , Mapeamento Cromossômico , Cromossomo X , Animais , Sequência de Bases , Carbono-Oxigênio Liases/genética , Sequência Conservada , DNA Liase (Sítios Apurínicos ou Apirimidínicos) , Desoxirribonuclease IV (Fago T4-Induzido) , Fator VIII/genética , Marcadores Genéticos , Humanos , Células Híbridas , Cariotipagem , Camundongos , Camundongos Endogâmicos BALB C , Cadeias Pesadas de Miosina/genética , Receptores Androgênicos/genética , alfa-Galactosidase/genéticaRESUMO
Heteroduplex Mobility Assays (HMAs) of 700 bp amplified products of a 17S rDNA region were used to identify and differentiate seven yeast species of clinical importance Candida albicans, Torulopsis (Candida) glabrata, Candida tropicalis, Candida parapsilosis, Candida (Pichia) guilliermondii and Hansenula (Pichia) anomala. Distance of heteroduplex migration (dHE) was found to be negatively correlated to the number of nucleotide differences between amplified DNA sequences.
Assuntos
Candida albicans/classificação , Candida/classificação , DNA Fúngico/análise , DNA Ribossômico/análise , Ácidos Nucleicos Heteroduplexes , Pichia/classificação , Sequência de Bases , Candida/genética , Candida/isolamento & purificação , Candida albicans/genética , Candida albicans/isolamento & purificação , Humanos , Dados de Sequência Molecular , Pichia/genética , Pichia/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Fatores de TempoRESUMO
Heteroduplex mobility assays (HMAs) of a cytochrome b region were used for estimating genetic distances and phylogenetic relationships between some selected neotropical primates of the families Callitrichidae (marmosets and tamarins) and Cebidae [capuchin monkey, (Cebus apella)], and man (Homo sapiens). HMA distances were found to be strongly correlated to analogous estimates derived from DNA sequence data. Phylogenetic trees obtained by HMAs and sequence analyses showed similar topologies with almost identical intraspecific, intrageneric, and intergeneric relationships. The applicability of HMAs is assessed relative to different levels of molecular and organismal diversity.