RESUMO
Bacterial DNA helicase RuvB protein is an essential component in homologous recombination and DNA double-strand break repair. Here, we report the gene structure of TIP49b/RUVBL2, a second putative human homologue of the bacterial RuvB gene. This gene contains 15 exons and 14 introns. The TIP49b/RUVBL2 open reading frame encodes a protein of 463 amino acids, showing 43% identity with the RUVBL1 protein. The TIP49b/RUVBL2 gene is physically linked to the human CGB/LHB gene cluster on chromosome 19q13.3. Genomic sequence analysis revealed that the TIP49b/RUVBL2 gene is very close (55 nucleotides in length) to the LHB gene, in the opposite orientation. The very close co-location of the mouse homologues of the human TIP49b/RUVBL2 and LHB genes was also conserved on mouse chromosome 7. Co-ordinated transcriptional regulation between the TIP49b/RUVBL2 and LHB genes was not observed. TIP49b/RUVBL2, like RUVBL1, was expressed ubiquitously in all human tissues examined and more strongly in testis. As TIP49b/RUVBL2 is expected to be involved in recombination repair and is located in a chromosome region frequently amplified in breast cancer, we quantified TIP49b/RUVBL2 gene expression by using real-time quantitative RT-PCR in a series of breast tumour samples. None of the tumour samples showed an altered TIP49b/RUVBL2 transcription level relative to normal breast tissue.
Assuntos
Proteínas de Bactérias/genética , Proteínas de Transporte/genética , Gonadotropina Coriônica/genética , Cromossomos Humanos Par 19/genética , DNA Helicases/genética , Hormônio Luteinizante/genética , ATPases Associadas a Diversas Atividades Celulares , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , Sequência de Bases , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Proteínas de Transporte/metabolismo , DNA Helicases/metabolismo , Feminino , Expressão Gênica , Ligação Genética , Humanos , Dados de Sequência Molecular , Família Multigênica/genética , RNA Mensageiro/metabolismo , Homologia de Sequência de Aminoácidos , Células Tumorais CultivadasRESUMO
BACKGROUND: A genetic syndrome of cutaneous malignant melanoma and nervous system tumors recently has been characterized and shown to be linked to the INK4 locus in the 9p21 region. Hemizygosity at adjacent physically mapped microsatellite markers indicated deletion of p16, p19, and p15 clustered tumor suppressors. Because individuals from this family could benefit from predictive testing in terms of cancer prevention, we developed a direct test without need to analyze parental DNAs to comply with the rules of individual consent and secrecy. METHODS: We developed an assay using TaqManTM real-time quantitative PCR, with p15 as the test sequence and albumin (ALB) as the reference gene. The normalized ratio of p15/ALB is expected to yield a value of approximately 1 in individuals without the deletion, whereas a ratio of approximately 0.5, indicating p15 haploinsufficiency, is expected in predisposed individuals. RESULTS: All patients harboring the previously defined at-risk haplotype were correctly identified using this approach. In six individuals with deletions, the p15/ALB ratios were 0.472-0.556 (SD, 0.013-0.078). In the five individuals without deletions, the ratios were 0.919-1.019 (SD, 0.006-0.075). CONCLUSIONS: This is the first report of a high-throughput, automatable gene dosage assay successfully applied to the identification of a germ-line deletion. This approach, not limited by marker informativeness or the need for harvesting live cells, can be applied to any condition with haploinsufficiency and extended to the characterization of most abnormalities of the ploidy.
Assuntos
Proteínas de Transporte/genética , Proteínas de Ciclo Celular , Inibidor p16 de Quinase Dependente de Ciclina , Genes Supressores de Tumor , Melanoma/genética , Neoplasias do Sistema Nervoso/genética , Proteínas Supressoras de Tumor , Inibidor de Quinase Dependente de Ciclina p15 , Dosagem de Genes , Haplótipos , Humanos , Linhagem , Reação em Cadeia da Polimerase , Síndrome , Taq PolimeraseRESUMO
Adipose tissue cellularity was studied in the 85-day-old Large-White pig fetus. The aim of this work was to count the adipose cells of forming tissue in an animal species which could be a possible model for studying adipose tissue in humans. Using a morphometric method with electron microscopy, mean triglyceride volume per cell was determined independently of mean cell volume. This method is suitable for counting adipose cells in the early stage of differentiation whatever their size and lipid inclusion volume. Site-by-site dissection of adipose tissue was not feasible in the 85-day old fetus and adipose cell number was computed by dividing total carcass triglyceride volume by mean triglyceride volume per cell. The carcass triglyceride seemed to originate only from adipose cells. The mean total carcass triglyceride volume per fetus (1.84 g) was low but, owing to the low mean triglyceride volume per cell (180.28 microns3), the adipose cell number (11.15 X 10(9)) was relatively important, as it represented about 27% of the extramuscular adipose cell number in the Large-White adult pig (41 X 10(9)).
Assuntos
Tecido Adiposo/citologia , Feto/citologia , Tecido Adiposo/análise , Tecido Adiposo/embriologia , Animais , Contagem de Células , Lipídeos/análise , Masculino , Microscopia Eletrônica , Suínos , Triglicerídeos/análiseRESUMO
Comparative studies were made to estimate the lipid overloading of myocardiac cells in rats fed by groups, for 3 and 6 days, one of the following dietary oils: peanut oil, maize oil, sunflower oi, soyabean oil, rapeseed-primor oil, rapeseed-canbra oil and rapeseed oil.
