SciELO Brasil - Scientific Electronic Library Online
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SciELO (Scientific Electronic Library Online) is an electronic library covering a selected collection of Brazilian scientific journals. The objective of the site is to implement an electronic virtual library, providing full access to a collection of serial titles, a collection of issues from individual serial titles, as well as to the full text of articles. The project envisages the development of a common methodology for the preparation, storage, dissemination and evaluation of scientific literature in electronic format.
Brazilian Journal of Genetics
Mostrando recursos 81 - 100 de 112
81.
Effects of Canola oil-based high fat diets on growth, fat deposition and serum triglyceride and cholesterol levels in lines of mice selected for high and low fat percentage - Benyon,L.S.; Eisen,E.J.; Jones,E.E.
This study was conducted to determine if there are biologically important interactions of genotypes of mice, differing in polygenically controlled body fat percentage, with levels of dietary fat from Canola oil which is rich in monounsaturated fat and low in saturated fat. Four levels of fat (12.5, 25, 37.5 and 50% of dietary energy) were provided ad libitum from four to seven, or four to 10 weeks of age to three lines of mice (HF, high body fat content; LF, low body fat content, and RC, random control with intermediate fat content). The lines were developed by directional selection for...
82.
The isozymatic pattern of alkaline phosphatase during ontogenetic development of Anastrepha fraterculus (Diptera: Tephritidae) - Nascimento,Jurema Cruz do; Oliveira,Alice Kalisz de
Eleven alkaline phosphatase (APH) electromorphs were detected during Anastrepha fraterculus (Diptera: Tephritidae) ontogenetic development. Specific isozymes were found in each stage analyzed (embryonic, larval, pupal and adult) and some isozymes were shared by two stages. A specific isozyme of the adult stage (Aph 0.37) occurred only in males 60 and 100 days old. Similar APH patterns were observed in third-stage larvae reared on four kinds of fruit (papaya, guava, banana and kiwi)
83.
Chromosomal multiformity in Botanochara bonariensis (Coleoptera, Chrysomelidae, Cassidinae) - Stolar,C.E.; Bidau,C.J.
The Cassidinae are characterized by highly conservative karyotypes, except in the Stolaini. This tribe shows the highest chromosome numbers in Coleoptera and complex chromosomal sex determination systems. We analyzed four natural populations of Botanochara bonariensis from Misiones and Entre Ríos Provinces (Argentina). The Concepción del Uruguay sample showed 2n = 47 (male) and 2n = 48 (female), the male meioformula being 22 II + XpneoXneoyp. The Itacurubí population showed 2n = 27 (male) and 2n = 26 (female), with a male meioformula of 12 II + neoXpneoy yp. The Mbororé and Ñu Porá populations showed 2n = 41 (male) and...
84.
Differences in the number of sensilla coeloconica and sensilla ampullacea of segment 10 of the antennae of Africanized and Caucasian bees and of their F1 hybrids - Stort,Antonio Carlos; Malaspina,Osmar
The numbers of sensilla coeloconica and sensilla ampullacea of segment 10 of the antennae of Caucasian and Africanized worker bees and of their hybrids were counted with the aid of a scanning electron microscope. Africanized bees have fewer sensilla than Caucasian bees and the continuous distribution obtained from the F1 values suggests polygenic inheritance for the control of this trait. There are also indications that the hybrid Brazilian Apis mellifera studied here are close to typical African bees (Apis mellifera scutellata) in terms of number of sensilla
85.
Characterization and distribution of supernumerary chromosomes in 23 colonies of Partamona helleri (Hymenoptera, Apidae, Meliponinae) - Magalhães Brito,Rute; Costa,Marco Antônio; Pompolo,Silvia G.
Partamona helleri has from zero to three supernumerary chromosomes. Analysis of 23 colonies demonstrated that there are two different types of supernumerary chromosomes, a submetacentric chromosome, which we called B1 type, and a smaller acrocentric chromosome which was designated B2 type. These chromosomes were differently distributed among individuals of the same colony and among individuals of different colonies. In some colonies, we also observed heteromorphism in the second pair of chromosomes, which may be related to the origin of the supernumerary chromosome system of this species
86.
Karyotype evolution in wasps of the genus Trypoxylon (subgenus Trypargilum) (Hymenoptera, Sphecidae) - Gomes,Luiz Fernando; das Graças Pompolo,Silvia; de Oliveira Campos,Lucio Antonio
We report the karyotypes of five wasp species of the genus Trypoxylon (subgenus Trypargilum): T. nitidum (2K = 10AM + 18A + 2CC), T. lactitarse (2K = 28AMC + 2CC), T. sp1 (K = 3AM + 10A + 2CC), T. sp2 (2K = 20AMC + 12A) and T. sp3 (2K = 2AMC + 30A). A comparison of the karyotypes of these species showed a small variation in chromosome number (2n = 30 and 32). However, much greater variation was observed when total arm number was compared (2AN = 34 to 60)....
87.
Amylase and protease secretion in recombinant strains of Metarhizium anisopliae var. anisopliae following parasexual crosses - Valadares-Inglis,M.C.; Azevedo,J.L.
Parasexual crosses were made between auxotrophic mutants of Metarhizium anisopliae var. anisopliae. Analysis of recombinants for secretion of amylases and proteases demonstrated that stable prototrophic recombinants have similar levels of enzyme secretion. Unstable prototrophic recombinants varied in amylase production, and segregants originating from these varied in protease secretion. Auxotrophic recombinants showed intense variation in secretion of amylases and proteases although there was no correlation between auxotrophic markers and enzyme production. There were significant differences in enzyme secretion between recombinants and parentals
88.
Cephalosporin C production and genetic improvement of the fungus Acremonium chrysogenum based on morphological mutant isolation - Vialta,Airton; Ferreira Catani,Cleide; Bonatelli Junior,Renato; Azevedo,João Lúcio
C-10 strain of the fungus Acremonium chrysogenum produced about 1.5 g/l of cephalosporin C, a yield that was much lower than expected according to the literature. This discrepancy, confirmed by exhaustive tests, showed that C-10 strain lost its high cephalosporin C production ability, probably due to genetic events. Strain improvement, based on isolation of morphologically compact mutant colonies, confirmed that this is a useful procedure for isolation of strains with increased titer. About 2% of tested colonies produced significantly more cephalosporin C than the original strain
89.
Sequence analysis of the catalytic domain of a Metarhizium anisopliae chitinase - Valadares-Inglis,Maria Cléria; Inglis,Peter W.; Peberdy,John F.
A 375-bp DNA fragment from Metarhizium anisopliae strain CG32 genomic DNA was amplified by PCR using chitinase-specific concensus primers. The deduced M. anisopliae peptide sequence demonstrated high similarity to the catalytic domains of chitinase genes from Aphanocladium album and Trichoderma harzianum. However, two introns present in the aligned A. album and T. harzianum genomic sequences were not detected in the M. anisopliae sequence. A comparison was made between this Metarhizium chitinase sequence and that of other fungi and bacteria. Possible phylogenetic relationships are discussed
90.
Brains and guts in human evolution: The Expensive Tissue Hypothesis - Aiello,Leslie C.
The brain is a very expensive organ in metabolic terms. Each unit of brain tissue requires over 22 times the amount of metabolic energy as an equivalent unit of muscle tissue. There is no correlation across mammals, however, between the relative size of the brain and the relative basal metabolic rate. The Expensive Tissue Hypothesis explains this apparent paradox by looking at the metabolic cost of the brain in the context of the costs of other metabolically expensive organs in the body. The results show that the increase in brain size in humans is balanced by an equivalent reduction in...
91.
Conflicting genomes, the demic theory & biodiversity - Hoenigsberg,H.F.
Organismic-centered Darwinism, in order to use direct phenotypes to measure natural selection's effect, necessitates genome's harmony and uniform coherence plus large population sizes. However, modern gene-centered Darwinism has found new interpretations to data that speak of genomic incoherence and disharmony. As a result of these two conflicting positions a conceptual crisis in Biology has arisen. My position is that the presence of small, even pocket-size, demes is instrumental in generating divergence and phenotypic crisis. Moreover, the presence of parasitic genomes as in acanthocephalan worms, which even manipulate suicidal behavior in their hosts; segregation distorters that change meiosis and Mendelian ratios;...
95.
Interphase cytogenetics using fluorescence in situ hybridization: an overview of its application to diffuse and solid tissue - Hackel,Christine; Varella-Garcia,Marileila
Interphase cytogenetics, utilizing fluorescence in situ hybridization (FISH) techniques, has been successfully applied to diffuse and solid tissue specimens. Most studies have been performed on isolated cells, such as blood or bone marrow cells; a few have been performed on cells from body fluids, such as amniotic fluid, urine, sperm, and sputum. Mechanically or chemically disaggregated cells from solid tissues have also been used as single cell suspensions for FISH. Additionally, intact organized tissue samples represented by touch preparations or thin tissue sections have been used, especially in cancer studies. Advantages and pitfalls of application of FISH methodology to each...
96.
Family names and the length of the Y chromosome in Brazilian blacks - Barbosa,Ana A.L.; Cavalli,Iglenir J.; Abé,Kiyoko; Santos,Maria G.; Azevêdo,Eliane S.
The variability of the lengths of the heterochromatic and euchromatic segments of the human Y chromosome was studied by a quantitative method of densitometric measurement in 60 normal and unrelated black individuals (30 with and 30 without devotional surnames), living in Salvador, Bahia, northeastern Brazil. Thirty normal and unrelated Caucasian individuals of European origin, living in Curitiba, Paraná, south Brazil, were included as controls. The heterochromatic segment and total Y chromosome lengths were greater in caucasians than in blacks without devotional surnames, and these were greater than in blacks with devotional surnames. These findings are in agreement with previous reports...
97.
Cytogenetic study of 50 Brazilian patients with primary myelodysplastic syndrome - Fernandez,Teresa de Souza; Silva,Maria Luiza M.; Souza,Jamison M. de; Tabak,Daniel; Abdelhay,Eliana
In this work we analyzed cytogenetically 50 patients with primary myelodysplastic syndrome from several hospitals of Rio de Janeiro, Brazil. The frequency of cytogenetic abnormalities was 32%. Patients with refractory anemia, or refractory anemia with ringed sideroblasts, presented normal karyotypes or single abnormalities such as del(5q) or -Y, while patients with refractory anemia with an excess of blasts, refractory anemia with an excess of blasts in transformation or chronic myelomonocytic leukemia showed complex karyotypes and single abnormalities involving chromosomes 7 or 8, which are related to a bad prognosis and an elevated risk of evolution to acute myeloid leukemia.
98.
Chromosome sensitivity to bleomycin in G2 lymphocytes from Down syndrome patients - Bartholomei-Santos,Marlise Ladvocat; Lucca,Edmundo José de
Several studies have demonstrated that lymphocytes from patients with Down syndrome (DS) exhibit an increased frequency of chromosome aberrations when they are exposed to ionizing radiation or to chemicals at the G0 or G1 phases of the cell cycle, but not at G2, when compared to normal subjects. To determine the susceptibility of DS lymphocytes at G2 phase, bleomycin, a radiomimetic agent, was used to induce DNA breaks in blood cultures from 24 Down syndrome patients. All the patients with DS showed free trisomy 21 (47,XX + 21 or 47,XY + 21). Individuals that showed an average number of chromatid...
99.
Intra and interspecific variability of in vitro culture response in Lycopersicon (tomatoes) - Pratta,Guillermo; Zorzoli,Roxana; Picardi,Liliana Amelia
Intra and interspecific variability was measured in the genus Lycopersicon for the traits: productivity rate (PR, total number of regenerated shoots/total number of cultures), regeneration percentage (%R, number of cultures regenerating shoots or primordia/total number of cultures) and callus percentage (%C, number of cultures only producing callus/total number of cultures). Leaf explants from various genotypes of L. esculentum, L. esculentum var. cerasiforme, L. pimpinellifolium and L. peruvianum were placed on Murashige and Skoog (Physiol. Plant. 15: 473-493, 1962) medium + 0.175 mg/l IAA + 2.25 mg/l BA. Significant differences among species and among genotypes within the same species were found,...
100.
Mapping of a novel viviparous unstable mutant of maize (vp 12) - Araujo,Paula G.; Silva,William J. da; Maluf,Mirian P.; Prioli,Laudenir M.
A new viviparous mutant of maize (Zea mays L.), associated with genetic instability and designated viviparous-12 (vp12), was identified in a synthetic Tuxpeño adapted to tropical regions. In the present work, the linkage group of this new locus was determined. Progenies of inbred line L477 segregating for the vp12 mutant were crossed with waxy-marked reciprocal translocation stocks. The phenotypic frequencies of the wx and vp12 mutants were analyzed in F2 progenies. The results demonstrated that the Viviparous-12 locus of maize is located on the long arm of chromosome 6.
81.
CC), T. lactitarse (2K = 28AMC + 2