|
|
|
| Registros recuperados: 8.210 | |
|
|
| Costa,Reginaldo Brito da; Resende,Marcos Deon Vilela de; Araújo,Antônio José de; Gonçalves,Paulo de Souza; Silva,Marcelo de Almeida. |
| The heritability coefficients and the genetic gains associated with individual, combined and among and within progeny selection, and with multi-effect index selection in long-term rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg.] breeding were determined using effective population size (Ne) restriction. Twenty-two half sib progenies were planted at the Jaú Experimental Station, São Paulo State, Brazil, in a complete randomized block design, with five replications and 10 plants per plot. The following traits were assessed when the plants were three years old: number of laticiferous vessel rings (NR), dry rubber production (RP), bark thickness (BT) and stem girth (SG). Significant variability was found among progeny with good chances of... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000200035 |
| |
|
|
| Tagliaro,Claudia Helena; Schneider,Maria Paula Cruz; Schneider,Horacio; Sampaio,Iracilda; Stanhope,Michael. |
| Traditional classifications of Platyrrhini monkeys, based mainly on morphological features, are being contested by recent molecular data. The subfamily Callitrichinae (Platyrrhini, Primates) consists of a diverse group of species, many of them considered endangered. Our analysis of two DNA regions, a mtDNA gene (ND1) and a nuclear gene (intronic regions of the transferrin gene), suggests that Callithrix pygmaea may have sufficient variability to justify the existence of subspecies or even separate species. Phylogenetic dendrograms based on the ND1 region show that this species is more closely related to Amazonian than to Atlantic forest marmosets. These results reopen the discussion about diversity and conservation programs based exclusively on traditional... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000400006 |
| |
|
| |
|
|
| Llerena Jr.,J.C.; Cabral de Almeida,J.C.; Bastos,E.; Crolla,J.A.. |
| Conventional cytogenetic studies on a female infant with sporadic aniridia revealed what appeared to be a balanced de novo t(11;13) (p13;q33) translocation. Fluorescence in situ hybridization (FISH) investigations, however, detected the presence of a cryptic 11p13p14 deletion which included the WAGR region and involved approximately 7.5 Mb of DNA, including the PAX6 and WT1 genes. These results account for the patient's aniridia, and place her at high risk for developing Wilms' tumour. The absence of mental retardation in the patient suggests that the position of the distal breakpoint may also help to refine the mental retardation locus in the WAGR contiguous gene syndrome (Wilms', aniridia, genital anomalies and mental retardation). |
| Tipo: Info:eu-repo/semantics/report |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000300006 |
| |
|
|
| Calcagnotto,Daniela; Toledo-Filho,Silvio de Almeida. |
| Knowledge and conservation of the genetic variability in stocks maintained as live gene banks have become a high priority task for Brazilian fish culture. The aim of the present survey was to assess the transferrin allelic diversity of five hatchery stocks of tambaqui (Colossoma macropomum). The tambaqui stock from Pentecoste, the oldest maintained in Brazilian hatchery stations, retained three of the six alleles detected in wild populations of tambaqui from the Amazon River. Other hatchery stocks, directly or indirectly derived from the Pentecoste stock, did not show transferrin allelic variability. Insufficient number of founders and genetic drift due to sampling errors seem to be the main causes leading to loss of genetic diversity in tambaqui hatchery... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000100023 |
| |
|
|
| Gabriel,Jane E.; Alves,Helena J.; Alvares,Lucia E.; Schmidt,Gilberto S.; Coutinho,Luiz L.. |
| In situ hybridization has provided insights into the molecular basis of skeletal myogenesis during embryonic development. In situ detection of different muscle-specific regulatory factors in whole embryos has been described. Spatial and temporal expression patterns of these factors differed among species. The expression pattern of MyoD in whole chicken embryos was studied via in situ hybridization using a probe obtained by the reverse transcription - polymerase chain reaction (RT-PCR) technique. In newly formed somites (embryos of stage 12), MyoD mRNA transcripts were detected along the anterior to posterior axis of somites immediately adjacent to the neural tube, whereas in mature somites (embryos of stage 24), MyoD transcripts were detected throughout... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000100027 |
| |
|
| |
|
| |
|
| |
|
|
| Renesto,Erasmo; Zawadzki,Cláudio Henrique; Revaldaves,Eloísa. |
| The existence of reproductive isolation between two morphs of catfish, endemic to the Iguaçu River (Brazil), was examined by enzyme starch gel electrophoresis. Tissues of 19 catfish (Pimelodus ortmanni) and 15 of a similar morph (Pimelodus sp.), which differs from P. ortmanni by presenting larger and more scattered dusky spots on its skin, were analyzed. A Nei's (1978) genetic identity of 0.551 was determined by the analysis of 22 enzyme loci. The loci EST*1, EST*2, GDH*1, GPI*1, GPI*2, IDH*1, MDH*1, MDH*2, and PGM*1 were fixed for different alleles in each morph, that is, no heterozygote was found for these loci. The enzymatic patterns observed for the two morphs indicate both that the taxa are reproductively isolated and that they in fact represent... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000400017 |
| |
|
| |
|
|
| Maria,Silvya Stuchi; Vidal,Benedicto de Campos; Mello,Maria Luiza S.. |
| Nuclear image analysis of Feulgen-stained V79 fibroblasts after three days in culture was used to discriminate apoptotic cells and cells suspected to be undergoing apoptosis from control cells based on parameters such as the Feulgen-DNA content, degree of chromatin condensation and nuclear areas, in association with visual morphology. The fibroblasts were initially plated at a density of 10(5) cells/ml and incubated under optimal culture conditions without subculturing. Following confluency, the cells underwent contact inhibition apoptosis. Image analysis revealed three nuclear phenotypes which were defined in terms of their morphological characteristics and levels of chromatin condensation. A decrease in the amount of Feulgen-DNA was detected in apoptotic... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000100020 |
| |
|
| |
|
|
| Karam,Simone M.; Costa,Jaderson C.; Jardim,Laura; Pires,Ricardo F.; Lehmann,Alan R.; Giugliani,Roberto. |
| Cockayne syndrome (CS) is an autosomal recessive disorder characterized by dwarfism, growth deficiency, neurological deterioration, skin photosensitivity and a characteristic progressive facial appearance. In the present study we report the first Brazilian CS family in which diagnosis was confirmed by the demonstration of decreased RNA synthesis in cultured fibroblasts exposed to UV-C radiation. Despite the progressive course of the disease and the unavailability of an effective treatment, diagnosis may be very important for the benefits to be gained by the afflicted family from genetic counseling and/or prenatal diagnosis. |
| Tipo: Info:eu-repo/semantics/other |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000200005 |
| |
|
|
| Guerra Jr.,José Carlos Vieira; Gonçalves,Lionel Segui; Jong,David De. |
| Africanized honey bees are more tolerant of infestations with the mite Varroa jacobsoni than are honey bees of European origin. The capacity of these bees to detect and react to brood infested with this mite could be one of the factors determining this tolerance. We tested colonies of Africanized bees headed by queens from swarms collected in Ribeirão Preto, São Paulo State. The Italian colonies had queens imported directly from the USA, or from the Brazilian Island of Fernando de Noronha, where varroa-infested Italian colonies have been maintained, untreated, since 1984. Recently sealed worker brood cells were artificially infested by opening the cell capping, inserting live adult female mites and resealing the cells. Control cells were treated in the... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000100016 |
| |
|
|
| Nascimento,Vania Alves; Matusita,Syomara Hakiko; Kerr,Warwick Estevam. |
| This report describes a case of hybridization between two species of Meliponinae bees (Melipona scutellaris from the Diamantina plateau in the State of Bahia, and Melipona capixaba from around Domingos Martins, in the State of Espírito Santo, Brazil). To demonstrate hybridization, electrophoretic profiles of esterase activity from three colonies were studied. Ten adult workers of M. scutellaris, M. capixaba and the hybrid colony were collected and processed individually. The pattern of esterase activity was constant for each species but differed between them, whereas hybrid bees had a pattern derived from both species. The fact that two ecologically different species of stingless bees separated by more than 300 km could still cross when placed in the same... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000100014 |
| |
|
| |
|
|
| Wojcik,A.; Kowalska,M.; Bouzyk,E.; Buraczewska,I.; Kobialko,G.; Jarocewicz,N.; Szumiel,I.. |
| The micronucleus assay is frequently used for purposes of biological dosimetry. Due to high interindividual variability in the spontaneous frequency of micronuclei, its sensitivity in the low dose region is poor. It has been suggested that this problem can be mitigated by selectively analyzing the frequency of those micronuclei which contain only acentric fragments. Using a pan-centromeric FISH probe we have studied the dose dependence of micronuclei with centromeres in peripheral lymphocytes of human donors. In contrast to previous publications, our approach is based on determining the relative frequency of micronuclei with and without centromeric signals. Our results confirm previous observations that in the low dose range of ionizing radiation, the... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000400055 |
| |
|
| |
|
|
| Echart-Almeida,Cinara; Cavalli-Molina,Suzana. |
| SDS-PAGE was used to analyze the hordein polypeptide patterns of Brazilian barley varieties (Hordeum vulgare L.) and of two native species of Hordeum from southern Brazil (H. euclaston Steud. and H. stenostachys Godr.). Forty different hordein polypeptide bands with molecular weights ranging from 30 to 94 kDa were found in the seeds of the three species studied. Twelve of the 14 varieties examined showed intravarietal polymorphism. The number of bands ranged from 10 to 17, depending on the variety, and from 3 to 13 among individual seeds, with a total of 26 bands in H. vulgare. Phenograms using each seed as an operational taxonomic unit (OTU) showed that the seeds from most varieties did not form distinct clusters. Seeds from different plants of the native... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000200031 |
| |
| Registros recuperados: 8.210 | |
|
|
|
