bluuebunny/crossref_metadata_2025 huggingface dataset:
Cystic fibrosis mutations R1162X and 2183AA®G in two southern Brasilian states
Authors: Pereira Lilian , Raskin Salmo , Freund Aline A. , Ribas Patrícia D. , Castro Raquel M.V. , Pignatti Pier F. , Culpi Lodércio
Published: April 2005

We screened 79 southern Brazilian patients with cystic fibrosis for the rare cystic fibrosis mutations R1162X and 2183AA®G. Forty-nine patients were born in the State of Paraná (PR) and 30 in the State of Santa Catarina (SC). Two 2183AA®G alleles were found among the SC patients and one among the PR patients. Six R1162X alleles were found among the SC patients and one among the PR patients. Fourteen percent of the alleles found among patients of Italian origin were R1162X, and 7% were 2183AA®G mutations. These mutations, together with DF508, were also studied in a sample of 270 normal non-related subjects of Italian origin who have been born in PR. In this sample we found two DF508 alleles and one 2183AA®G allele. DF508, R1162X and 2183AA®G frequencies were not statistically different from those observed in Italy. Our results demonstrate that it is important to include these mutations in southern Brazilian surveys of cystic fibrosis patients, especially when they are of Italian descent.
Intrapopulational genetic differentiation in Anopheles (N.) darlingi Root, 1926 (Diptera: Culicidae) in the amazon region
Authors: Santos Joselita Maria Mendes dos , Lobo Jorge Arturo , Tadei Wanderli Pedro , Contel Eucleia P. Betioli
Published: April 2005

Four natural Amazonian Anopheles darlingi populations were analyzed for 19 loci, 12 of which showed variation, i.e., 68.4% of polymorphic loci. The Ariquemes, Rondônia, population was the most variable, with a large number of alleles per locus (2.26 ± 0.27) and high polymorphism (P = 63.15). The highest values of observed and expected intralocus heterozygosity were observed in the Manaus, Amazonas, population (Ho = 0.432 ± 0.11; He = 0.375 ± 0.08), and the lowest in the Cachoeira Porteira, Pará, population (Ho = 0.236 ± 0.09; He = 0.290 ± 0.11). Wright's F-statistic revealed disequilibrium caused by an excess of homozygotes, as shown by the Fis > Fst values (Fis = 0.083 > 0.026) reflecting intrapopulational differentiation. The four populations studied were genetically similar, as indicated by distance and similarity values. Chromosomal variation of Amazon population also did not indicate geographical differentiation, and populations in the central region of the Amazon Basin showed high polymorphism in relation to the marginal populations, which were mainly monomorphic.
Autosomal rearrangement in Gryllus assimilis Fabricius, 1775 (Orthoptera, Gryllidae)
Authors: Zefa Edison
Published: April 2005

Gryllus assimilis L. has a karyotype of 2n = 29 (X0, male) and 30 (XX, female). The above karyotype was encountered along with another in which 2n = 28 (X0, male) and 2n = 29 (XX, female) in a population from the outskirts of Rio Claro city (São Paulo State, Brazil). Of eight specimens studied, five had the heterozygous karyotype involving a translocation and three had the basic karyotype. There were no individuals homozygous for the rearrangement. The heterozygous karyotype was the result of a chromosomal rearrangement between chromosome pairs 6 and 10, both of which were initially submetacentric. The members of the sixth pair normally have two constrictions in the small arm, with a satellite at the chromosome tip. The chromosome of the tenth pair involved in the translocation was generally submetacentric and probably underwent a pericentric inversion which transported the centromere to a subterminal position before being translocated. In this case, the long arm of the inverted chromosome of the tenth pair was translocated with the satellite of a member of the sixth pair.
Phylogenetic relationships among Brazilian howler monkeys, genus Alouatta (Platyrrhini, Atelidae), based on g1-globin pseudogene sequences
Authors: Meireles Carla Maria , Czelusniak John , Ferrari Stephen F. , Schneider Maria Paula Cruz , Goodman Morris
Published: April 2005

The genus Alouatta (howler monkeys) is the most widely distributed of New World primates, and has been arranged in three species groups: the Central American Alouatta palliata group and the South American Alouatta seniculus and Alouatta caraya groups. While the latter is monotypic, the A. seniculus group encompasses at least three species (A. seniculus, A. belzebul and A. fusca). In the present study, approximately 600 base pairs of the g1-globin pseudogene were sequenced in the four Brazilian species (A. seniculus, A. belzebul, A. fusca and A. caraya). Maximum parsimony and maximum likelihood methods yielded phylogenetic trees with the same arrangement: {A. caraya [A. seniculus (A. fusca, A. belzebul)]}. The most parsimonious tree had bootstrap values greater than 82% for all groupings, and strength of grouping values of at least 2, supporting the sister clade of A. fusca and A. belzebul. The study also confirmed the presence of a 150-base pair Alu insertion element and a 1.8-kb deletion in the g1-globin pseudogene in A. fusca, features found previously in the remaining three species. The cladistic classification based on molecular data agrees with those of morphological studies, with the monospecific A. caraya group being clearly differentiated from the A. seniculus group.
Cytogenetic studies of two freshwater sciaenids of the genus Plagioscion (Perciformes, Sciaenidae) from the central Amazon
Authors: Feldberg Eliana , Porto Jorge Ivan Rebelo , Santos Elen Bethlen Pedraça dos , Valentim Francisco Carlos Souza
Published: April 2005

Cytogenetic characterization of two freshwater sciaenid species from the genus Plagioscion (P. squamosissimus and Plagioscion sp.) was obtained for the first time. Giemsa staining, Ag-NOR and C-banding revealed that both species presented 2n = 48 chromosomes (almost all acrocentric). Single NORs and heterochromatin were found mainly at the pericentromeric position. Karyotypic formulae and NOR location proved to be valuable in showing both interspecific and intraspecific differences. All chromosomes were acrocentric in P. squamosissimus. NORs were located at proximal positions on the long arms of the last chromosome pair of the complement, and were heteromorphic due to size differences. Such heteromorphic NORs seem to be associated with each population sampled. Plagioscion sp. presented two cytotypes: cytotype a (2M + 46A) and cytotype b (48A). In both cytotypes, NOR-bearing chromosomes were located at the proximal position on the long arms of the first chromosome pair of the complement. However, NOR-bearing chromosomes were metacentric in cytotype a and acrocentric in cytotype b.
Heterochromatin patterns and karyotype relationships within and between the genera Brycon and Salminus (Pisces, Characidae)
Authors: Margarido Vladimir Pavan , Galetti Junior Pedro Manoel
Published: April 2005

Chromosomes of two Brycon species (B. lundii and B. microlepis) and Salminus hilarii were analyzed. Based on constitutive heterochromatin distribution patterns, karyotypic relationships within and between Bryconinae and Salmininae were examined. A monophyletic origin for the genus Brycon, comprising at least two chromosome synapomorphies (presence of two large submetacentric bearing paracentromeric and telomeric heterochromatin), is suggested. Moreover, Bryconinae and Salmininae may represent a monophyletic unit among Characidae, as they share several chromosome features.
Genetic parameters of test day milk yields of Holstein cows
Authors: Machado S.G. , Freitas M.A.R. , Gadini C.H.
Published: April 2005

Data were obtained from 17,968 records from 2,130 first lactations of Holstein cows calving between 1988 and 1991. The subjects were daughters of 136 sires monitored by Brazilian Breeders Association, Animal Science Institute, Department of Agriculture, a branch of the State of São Paulo. Data were divided into 10 subsets based on the number of days in milk yield. Test day milk yields (M1 to M10) and 305-day milk yield (M305) were the traits studied. These traits were adjusted for several environmental effects: class of cow age at calving, interval from calving to first test day, and herd-year-season. Restricted maximum likelihood estimates of (co)variance components were obtained from one and two-traits analysis under a sire model. Estimates of heritabilities for M ranged from 0.04 to 0.32. The highest values were found in the second half of lactation (M5 to M7). Heritability estimate for M305 was 0.32. Genetic correlations between individual test days and M305 ranged from 0.78 to 1.00. Results suggested that test day milk yields, mainly in mid-lactation, can be used instead of 305-day milk yield in genetic evaluations, because estimates of these two-trait heritabilities are nearly alike. Moreover, early selection can reduce generation intervals.
Conservation genetics of an endangered Catalonian cattle breed ("Alberes")
Authors: Jordana J. , Piedrafita J. , Carre X. , Martell A.
Published: April 2005

We biochemically analyzed and characterized the genetic structure of a population in danger of extinction ,"Alberes", a local cattle breed of the Catalonian Pyrenees (Spain and France). Ninety-two individuals were analyzed for five polymorphic genetic loci (Hb, Alb, Tf, Gc and Ptf2). The animals were grouped according to coat color: Fagina Alberes variety (N = 39) and Black Alberes variety (N = 53). The genetic structures and relationships between these subpopulations and one "outgroup" breed ("Bruna dels Pirineus") were analyzed and compared by using F-statistics. We determined that inbreeding in the Alberes breed is not significant, since negative and nonsignificant FIT and FIS values were obtained. The average genetic differentiation between subpopulations within the Alberes breed was 1.5% (FST = 0.015; P < 0.05), with an effective number of 4.1 individuals exchanged between subpopulations per generation (gene flow). The results obtained in this study corroborate the potential danger of extinction of the breed. The Black Alberes variety is proposed as the principal nucleus of genetic conservation for this breed, as it seems to show a higher degree of genetic isolation from other foreign populations.
A leukocyte cryopreservation technique for cytogenetic studies
Authors: Duarte José Maurício Barbanti , Ramalho Mariney Flávia Pereira Di Tano , Lima Vera Fernanda Hossepian de , Jorge Wilham
Published: April 2005

Several culture, cryopreservation, freezing and thawing methods were tested to develop an efficient technique for storing cervid and ovine leukocytes. The best results were obtained with McCoy or Vega y Martinez (VYM) solution with dimethyl sulfoxide (DMSO), horse serum and polyvinylpyrrolidone (PVP) as cryopreservatives. The best protocol for freezing was 4°C for 30 min followed by 15 min in liquid nitrogen vapor. To thaw, the still frozen material was placed onto cultivation medium for propagation.
Comparison of similarity coefficients based on RAPD markers in the common bean
Authors: Duarte Jair Moura , Santos João Bosco dos , Melo Leonardo Cunha
Published: April 2005

The alterations caused by eight different similarity coefficients were evaluated in the clustering and ordination of 27 common bean (Phaseolus vulgaris L.) cultivars analyzed by RAPD markers. The Anderberg, simple matching, Rogers and Tanimoto, Russel and Rao, Ochiai, Jaccard, Sorensen-Dice, and Ochiai II's coefficients were tested. Comparisons among the coefficients were made through correlation analysis of genetic distances obtained by the complement of these coefficients, dendrogram evaluation (visual inspection and consensus fork index - CIC), projection efficiency in a two-dimensional space, and groups formed by Tocher's optimization procedure. The employment of different similarity coefficients caused few alterations in cultivar classification, since correlations among genetic distances were larger than 0.86. Nevertheless, the different similarity coefficients altered the projection efficiency in a two-dimensional space and formed different numbers of groups by Tocher's optimization procedure. Among these coefficients, Russel and Rao's was the most discordant and the Sorensen-Dice was considered the most adequate due to a higher projection efficiency in a two-dimensional space. Even though few structural changes were suggested in the most different groups, these coefficients altered some relationships between cultivars with high genetic similarity.
Association between Griffing's diallel and the adaptability and stability of Eberhart and Russel
Authors: Pacheco Cleso Antônio Patto , Cruz Cosme Damião , Santos Manoel Xavier dos
Published: April 2005

The objective of the present work was to provide a methodology to study the inheritance of adaptability and stability through the breakdown of Eberhart and Russell regression coefficients and regression deviations in effects due to the mean and additive genetic effects (gi's and gj's) as well as dominance effects (sij's) of Griffing´s methodology, when the diallel is conducted in several environments. It was concluded that the adaptability and stability parameters are determined in the same manner as are genetic effects. So an F1 cross inherits half the general combining ability (GCA) mean effect from each parent, while the effects due to specific combining ability (SCA) are subjected to the same considerations relative to sij's, i.e., they are dependent on specific combinations.
Premature ovarian failure (POF) in Brazilian fragile X carriers
Authors: Vianna-Morgante Angela M. , Costa Silvia S. , Pavanello Rita de C.M. , Otto P.A. , Mingroni-Netto Regina C.
Published: April 2005

The gynecological and reproductive histories of 193 women from fragile X families were surveyed. Among the 101 carriers of the premutation, 14 experienced premature menopause, contrarily to their 37 fully mutated and 55 noncarrier female relatives. Although premature menopause showed a tendency to cluster in certain fragile X families, as a group, the premutated women experienced menopause earlier than noncarriers. This suggests that premature menopause may be the extreme effect of a spectrum of ovarian anomalies associated with the fragile X premutation.
Haldane's rule and other aspects of reproductive isolation observed in the Anastrepha fraterculus complex (Diptera: Tephritidae)
Authors: Selivon Denise , Perondini André L.P. , Morgante João S.
Published: April 2005

Some aspects of reproductive isolation between allopatric populations of two closely related species of the Anastrepha fraterculus complex (A. fraterculus sp. 1 and sp. 2) were evaluated in laboratory conditions. Most of the crosses were fertile in each species as well as between sp. 2 females and sp. 1 males. In the reciprocal cross only 41.7% of the matings yielded viable progeny. Egg hatching occurred at similar rates within the two species, but was significantly lower in the crosses between the species. Adult emergence did not differ significantly among crosses. The sex ratio of adult progeny within each species, as well as in the hybrid progeny derived from sp. 1 females crossed to sp. 2 males, did not differ from the expected 1:1 ratio. However, in the crosses between sp. 2 females to sp. 1 males, a significant deviation in the sex ratio in favor of females was observed, according to the Haldane's rule. The results reinforce previous data which indicated that A. fraterculus sp. 1 and A. fraterculus sp. 2 are distinct biological entities.
Phenotypic plasticity in colonizing populations of Drosophila subobscura
Authors: Pegueroles Glòria , Mestres Francesc , Argemí Mercè , Serra Lluís
Published: April 2005

The phenotypic plasticity of some quantitative traits of two colonizing populations of Drosophila subobscura (Davis and Eureka, California) was studied. Temperature effects and the effect of rearing in the laboratory were studied. Laboratory rearing during four generations at 18ºC significantly increased the wing and tibial length. This increase was similar to that obtained when the flies were reared at 13ºC during two generations.The low temperature environment can be considered more stressful for females than for males, as shown by the increase of phenotypic variance. The two populations analyzed had great phenotypic plasticity in spite of the genetic bottleneck during the colonization event. Our study shows that keeping flies for a relatively short time in the laboratory significantly changes some quantitative traits, emphasizing the need to analyze flies immediately after collecting them in order to obtain reliable estimates for the analysis of these traits in natural populations.
In situ DNA transfer to chicken embryos by biolistics
Authors: Ribeiro Luciana A. , Azevedo João L. , Aragão Francisco J.L. , Rech Elibio L. , Schmidt Gilberto S. , Coutinho Luiz L.
Published: April 2005

Fertilized chicken eggs were bombarded with a biolistic device. Transient expression of the lacZ gene under the control of a human cytomegalovirus (CMV) promoter was assessed after in situ gene transfer using this approach. The influence of different pressures, vacuum levels and particles was tested. Survival rate improved as particle velocity decreased, but resulted in lower levels of expression. The best survival and expression were obtained with gold particles, a helium gas pressure of 600 psi and a vacuum of 600 mmHg. Under these conditions, all bombarded embryos showed b-galactosidase activity, indicating that this was an effective method for transformation of chicken embryos.
Identification of common bean alleles resistant to anthracnose using RAPD
Authors: Castanheira Ana L.M. , Santos João B. dos , Ferreira Daniel F. , Melo Leonardo C.
Published: April 2005

RAPD markers were identified close to common bean alleles responsible for resistance to the fungus Colletotrichum lindemuthianum and may be useful in selecting plants resistant to this pathogen. DNA from F2 plants of the crosses Carioca 300V x P45, Carioca 300V x Ouro and P24 x Ouro was amplified by RAPD. Line P45 has the Co.4 allele for resistance, and the Ouro cultivar has the Co.5 allele. The primer OPC08 amplified a DNA fragment of about 1059 bp linked to the Co.4 allele. The recombination frequency was 0.133 (SE = 0.039; 95% CI = 0.056-0.211). Using the primer OPF10 a DNA fragment of about 912 bp was amplified and found to be associated with the Co.5 allele. The recombination frequency was 0.115 (SE = 0.038; 95% CI = 0.041-0.189). A second marker (1122 pb) amplified by the OPR03 primer was identified in the population P24 x Ouro. The recombination frequency for this marker was 0.363 (SE = 0.081; 95% CI = 0.205-0.522). Both these markers flanked the Co.5 allele. The markers identified in this study may be useful in identifying lines with the Co.4 and Co.5 alleles.
Theory and analysis of partial diallel crosses
Authors: Viana José Marcelo Soriano , Cruz Cosme Damião , Cardoso Antonio Américo
Published: April 2005

This study presents theory and analysis of partial diallel crosses based on Hayman's methods. This genetic design consists of crosses among two parental groups. It should be used when there are two groups of parents, for example, dent and flint maize inbred lines, and the breeder is not interested in the assessment of crosses between parents of the same group. Analyses are carried out using data from the parents and their F1 hybrids allowing a detailed characterization of the polygenic systems under study and the choice of parents for hybridization. Diallel analysis allows the estimation of genetic and non-genetic components of variation and genetic parameters and to assess the following: genetic variability in each group; genotypic differences between parents of distinct groups; if a parent has a common or a rare genotype in the group to which it does not belong; if there is dominance; if dominant genes increase or decrease trait expression (direction of dominance); average degree of dominance in each group; the relative importance of mean effects of genes and dominance in determining a trait; if, in each group, the allelic genes have the same frequency; if genes are equally frequent in the two groups; the group with the greatest frequency of favorable genes; the group in which dominant genes are most frequent; the relative number of dominant and recessive genes in each parent; if a parent has a common or a rare genotype in the group to which it belongs, and the genotypic differences between parents of the same group. An example with common bean varieties is considered.
The anticancer agent PB-100, selectively active on malignant cells, inhibits multiplication of sixteen malignant cell lines, even multidrug resistant
Authors: Beljanski Mirko
Published: April 2005

The plant-derived anticancer agent PB-100 selectively destroys cancer cells, even when multidrug resistant; yet, it does not inhibit normal (non-malignant) cell multiplication. Testing of PB-100 on sixteen malignant cell lines, several multidrug resistant, as well as on five normal cell lines, confirmed our previous results. Flavopereirine and dihydroflavopereirine, the active principles of PB-100, were chemically synthesized and displayed the same selectivity for tumor cells as the purified plant extract, being active at even lower concentrations.
Genetic divergence in mitochondrial DNA of Anopheles nuneztovari (Diptera: Culicidae) from Brazil and Colombia
Authors: Scarpassa Vera Margarete , Geurgas Silvia , Azeredo-Espin Ana Maria L. , Tadei Wanderli Pedro
Published: April 2005

In the present study, we have examined the variability in Anopheles nuneztovari mitochondrial DNA of three populations from the Brazilian Amazon and one from western Colombia (Sitronela), using four restriction endonucleases (BclI, ClaI, HindIII, SstI). The haplotype diversity (h) was slightly elevated in all populations (0.5000 to 0.6765), whereas the nucleotide diversity (pi) was lower in the Sitronela population (0.0029) and higher in populations from the Brazilian Amazon (0.0056 to 0.0098). The degree of sequence divergence (delta) estimated within the Brazilian Amazon and that in Sitronela (0.0329 to 0.0371) suggests that these geographic populations of A. nuneztovari may eventually constitute separate species. The low sequence divergence values among the three Brazilian Amazon populations (0.0012 to 0.0031) indicate that these populations are genetically similar. These results are consistent with those recently reported for allozymes of these same populations.
Ovarian development in Meliponine bees (Hymenoptera: Apidae): the effect of queen presence and food on worker ovary development and egg production
Authors: Cruz-Landim Carminda da
Published: April 2005

Morphological studies of Meliponine worker ovaries in five species indicated a possible stimulatory effect of the queen on ovary development and on the production of trophic eggs in some of them. There are also indications that the queen inhibits the production of fertile eggs by the workers. This inhibition may involve a delay in the development of fertile eggs by the worker, until she is out of direct contact with the queen, or a lack of ovary development in the queen's presence, as seen in Leurotrigona muelleri. The evolutionary tendency toward inability to produce fertile eggs has its extreme representation in the pupal worker ovary reabsorption found in Frieseomelitta silvestri. On the other hand, the finding, in some species, of dwarf queens with the basic number of ovarioles (four) in the ovaries, along with normal, trophically determined queens with larger numbers of ovarioles in the ovaries demonstrate the influence of food on this character, as in Apis mellifera.
Changes in the structure and pigmentation of the eyes of honeybee (Apis mellifera L.) queens with the "limão" mutation
Authors: Chaud-Netto José , Cruz-Landim Carminda da
Published: April 2005

This study describes the ultrastructural differences between the compound eyes of ch li/ch li and Ch/ch li honeybee queens. Heterozygous "limão" bees had an almost normal ultrastructural organization of the ommatidia, but there were some alterations, including small vacuoles in the crystalline cones and a loss of pigment by primary pigmentary cells. In homozygous bees many ommatidia had very deformed crystalline cones and there were some bipartite rhabdoma. There was a reduction in the amount of pigment in the primary and secondary pigmentary cells and receptor cells (retinulae) of mutant eyes. However, the eyes of both heterozygous and homozygous queens had the same type of pigment granules. Certain membrane-limited structures containing pigment granules and electron-dense material appeared to be of lysosomal nature. Since these structures occurred in the retinular cells of mutant eyes, they were considered to be multivesicular bodies responsible for the reduction in rhabdom volume in the presence of light, as a type of adaptation to brightness. The reduction of pigment in the pigmentary and retinular cells and the morphological changes seen in the rhabdom of the ommatidia may originate visual deficiencies, which could explain the behavioral modifications reported for Apis mellifera queens with mutant eye color.
Image analysis of DNA fragmentation and loss in V79 cells under apoptosis
Authors: Maria Silvya Stuchi , Vidal Benedicto de Campos , Mello Maria Luiza S.
Published: April 2005

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 cells and in cells suspected of undergoing apoptosis. This decrease was assumed to indicate DNA loss. Image analysis procedures may therefore provide a useful tool for discriminating cells in the early stages of apoptosis.
Loss of genetic variability at the transferrin locus in five hatchery stocks of tambaqui (Colossoma macropomum)
Authors: Calcagnotto Daniela , Toledo-Filho Silvio de Almeida
Published: April 2005

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 stocks. Appropriate management strategies are required in order to improve the genetic potential of tambaqui stocks in Brazil.
In situ detection of transcripts of the myogenic factor MyoD in whole chicken embryos
Authors: Gabriel Jane E. , Alves Helena J. , Alvares Lucia E. , Schmidt Gilberto S. , Coutinho Luiz L.
Published: April 2005

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 the entire somite. These results indicate that MyoD expression is important for initiating and maintaining the avian myogenic system.
Identification of proliferating cells in chicken embryos using 5-bromo- 2'-deoxyuridine immunohistochemical detection
Authors: Lopes Mário Lúcio , Schmidt Gilberto Silber , Coutinho Luiz Lehmann
Published: April 2005

Chicken embryos were incubated with BrdU, embedded in plastic resin, sectioned and screened immunohistochemically to identify proliferating cells in the neural tube and somites. Fixation in 4% paraformaldehyde for 1 h was essential for detecting specific colorimetric signals of BrdU incorporation into cells during the S phase of the cell cycle. Transverse sections of the neural tube showed that the nuclei of proliferating cells (BrdU positive) had a uniform and centralized distribution, whereas unstained nuclei were found only along the extremities of the neural tube. Transverse sections of differentiated somites showed proliferating cells in the scleratome and dermatome. However, no incorporation of BrdU was observed in myotomic cells, which give rise to axial skeletal muscle. In spite of their proximity, the dermatome and myotome showed marked differences in cell proliferation. The excellent preservation of morphological characteristics in the embryonic tissues facilitated identification of variations in BrdU incorporation.
Effects of Phaseolus vulgaris QTL in controlling host-bacteria interactions under two levels of nitrogen fertilization
Authors: Souza Alessandra A. , Boscariol Raquel L. , Moon David H. , Camargo Luis E.A. , Tsai Siu M.
Published: April 2005

Molecular markers were used to estimate the effect of mineral nitrogen on the phenotypic expression of quantitative trait loci (QTL) controlling the number of Rhizobium nodules (NN) and resistance to Xanthomonas axonopodis pv. phaseoli in the common bean. Recombinant inbred lines derived from a BAT-93 x Jalo EEP558 cross were grown in a greenhouse in the absence or presence (5 mM NH4NO3) of nitrogen. Resistance to Xanthomonas was assessed as diseased leaf area (DLA) and the number of nodules was obtained by direct counting. Analyses of variance were used to detect significant associations between 85 marker loci from 12 linkage groups (LG) and quantitative traits. In the absence of nitrogen, 15 and 11 markers, distributed over 7 and 5 LG, showed a significant association with NN and DLA, respectively. The combined percentage of phenotypic variance explained by the marker-loci and QTL associations was 34% for NN and 42% for DLA. In the presence of nitrogen, there were only five significant associations for NN and eight for DLA, which explained 28 and 26% of the total phenotypic variance, respectively. The effects of some QTL were detected only at a certain level of nitrogen. The contribution of parental alleles at two NN QTL was dependent on the level of nitrogen. Four QTL were associated with both the number of Rhizobium nodules and resistance to Xanthomonas, suggesting a common genetic control of responses to bacterial infections in the common bean. Despite the dramatic environmental interactions noted with some QTL, in other cases the phenotypic effects were not affected by the amount of nitrogen. The stability of the latter QTL may be relevant when breeding cultivars adapted to variable soil fertility.
Isoenzymatic polymorphism in Citrus spp. and Poncirus trifoliata (L.) Raf. (Rutaceae)
Authors: Novelli Valdenice Moreira , Machado Marcos Antonio , Lopes Catalina Romero
Published: April 2005

Isoenzymatic polymorphism analysis was used to determine genetic variability among species and hybrids of Citrus spp. and one accession of Poncirus trifoliata (L.) Raf. Ten enzymatic systems aspartate aminotransferase (AAT), acid phosphatase (ACP), leucine aminopeptidase (LAP), 6-phosphogluconate dehydrogenase (6-PGD), isocitrate dehydrogenase (IDH), phosphoglucoisomerase (PGI), phosphoglucomutase (PGM), diaphorase (DIA), shikimate dehydrogenase (SKD) and peroxidase (PRX) were analyzed. Twenty loci and 48 alleles were identified. Sweet orange cultivars (C. sinensis (L). Osbeck) showed the highest polymorphism with the largest number of heterozygous loci, although the alleles of those loci were the same in all cultivars, with the exception of Westin and Lima graúda. Mandarins (C. reticulata Blanco) exhibited diverse patterns, whereas Poncirus trifoliata (L.) Raf. showed high variability with all Citrus species and hybrids. Exclusive phenotypes were observed in some enzymatic systems, and similar patterns were found among interspecific hybrids and their putative parents.
Chromosome numbers in Bromeliaceae
Authors: Cotias-de-Oliveira Ana Lúcia Pires , Assis José Geraldo Aquino de , Bellintani Moema Cortizo , Andrade Jorge Clarêncio Souza , Guedes Maria Lenise Silva
Published: April 2005

The present study reports chromosome numbers of 17 species of Bromeliaceae, belonging to the genera Encholirium, Bromelia, Orthophytum, Hohenbergia, Billbergia, Neoglaziovia, Aechmea, Cryptanthus and Ananas. Most species present 2n = 50, however, Bromelia laciniosa, Orthophytum burle-marxii and O. maracasense are polyploids with 2n = 150, 2n = 100 and 2n = 150, respectively, while for Cryptanthus bahianus, 2n = 34 + 1-4B. B chromosomes were observed in Bromelia plumieri and Hohenbergia aff. utriculosa. The chromosome number of all species was determined for the first time, except for Billbergia chlorosticta and Cryptanthus bahianus. Our data supports the hypothesis of a basic number of x = 25 for the Bromeliaceae family and decreasing aneuploidy in the genus Cryptanthus.
Genotype-environment interaction and the number of test sites for the genetic improvement of rubber trees (Hevea) in São Paulo State, Brazil
Authors: Costa Reginaldo Brito da , Resende Marcos Deon Vilela de , Araujo Antonio José de , Gonçalves Paulo de Souza , Martins Antonio Lúcio Mello
Published: April 2005

The present study quantifies the possible genotype-environment interactions and determines the ideal number of test sites for rubber trees [Hevea brasiliensis (Willd ex Adr. de Juss.) Muell Arg] in the plateau region of São Paulo State. The study was based on the genetic correlation among progenies at three different sites and on estimates of genetic gains with indirect selection of rubber trees. Twenty-two half-sib progenies were planted at the Jaú, Pindorama and Votuporanga experimental stations using random blocks with five replications and 10 plants per plot. At three years of age, the plants were evaluated for their total number of latex ring vessels (NR), rubber production (RP), bark thickness (BT) and girth (SG). There was significant genetic variability in the characters RP, SG and BT, mainly among progenies from Pindorama and Votuporanga. The effects of genotype-site interactions were significant for RP and SG. The finding of significant interactions was not a complicating factor because of the large genetic correlation detected. These results indicate that the use of two sites is more profitable when the gains in efficiency of selection are greater than 10%. Thus, Pindorama and Votuporanga will satisfactorily attend the studied region.
Caffeine content of Ethiopian Coffea arabica beans
Authors: Silvarolla Maria Bernadete , Mazzafera Paulo , Lima Marinez Muraro Alves de
Published: April 2005

The coffee germplasm bank of the Instituto Agronômico de Campinas has many Coffea arabica accessions from Ethiopia, which is considered the primary center of genetic diversity in coffee plants. An evaluation of the caffeine content of beans from 99 progenies revealed intra- and inter-progeny variability. In 68 progenies from the Kaffa region we found caffeine values in the range 0.46-2.82% (mean 1.18%), and in 22 progenies from Illubabor region these values ranged from 0.42 to 2.90% (mean 1.10%). This variability could be exploited in a breeding program aimed at producing beans with low-caffeine content.
Interactions in the Agrobacterium-soybean system and capability of some Brazilian soybean cultivars to produce somatic embryos
Authors: Mauro Antonio Orlando Di , Nóbrega José Carlos Martins de , Mauro Sonia Marli Z. Di , Collins Glenn Burton
Published: April 2005

Twenty-five Brazilian soybean cultivars were studied for susceptibility to four strains of Agrobacterium tumefaciens (C58, Ach5, Bo542 and A281) and for their ability to produce somatic embryos. Twelve plants of each cultivar were inoculated in a greenhouse at 4-6 weeks of age, using 12 inoculation sites per plant. The number of galls formed on plants were counted 8-10 weeks after inoculation. To study ability to produce somatic embryos, immature cotyledons, 4-6 mm in length, were plated onto N10 medium for induction of somatic embryogenesis, using four Petri dishes with 20 cotyledons for each cultivar. The embryogenic tissues were transferred onto new N10 medium six times at 15-day intervals and the number of somatic embryos per cultivar determined. Significant interaction between soybean cultivars and A. tumefaciens strains was observed; the most virulent strain was A281. The opine type apparently had no effect on strain virulence, and the most embryogenic cultivars were IAS-5, Cristalina, FT-Cometa, IAC-7 and OC-3.
Genetic analisys of a cross of gaillon (Brassica oleracea var. alboglabra) with cauliflower (B.oleracea var. botrytis)
Authors: Spini Vanessa B.M.G. , Kerr Warwick Estevam
Published: April 2005

The cauliflower (Brassica oleracea var. botrytis) is an annual vegetable cultivated in Southern and Southwestern Brazil with limited production in the Northeast and Centralwest. A variety of Chinese kale, "kaai laan" or "gaillon" (Brassica oleracea var. alboglabra), produces seeds at high temperatures and therefore can do so in North and Northeastern Brazil. Gaillon and cauliflower were crossed 55 times using 10 gaillon plants as mothers and 4 cauliflower plants as pollen donors. From these crosses, in the F2 generation, 612 plants with inflorescence like gaillon and 48 plants with inflorescence like cauliflower were obtained, in a proportion similar to 15:1, implying that 2 pairs of genes entered into formation of the cauliflower inflorescence type. In order to study flower color, 339 plants were analyzed: 274 presented white flowers and 65, yellow flowers, denoting that this caracter is determined by 1 pair of genes, white being dominant over yellow; white flowers had a slighly higher adaptive value in our population. The characteristic waxy leaf showed a proportion of 3 waxy plants for 1 not waxy, indicating the action of one pair of genes.
An alkaline single-cell gel electrophoresis (comet) assay for environmental biomonitoring with native rodents
Authors: Silva Juliana da , Freitas Thales R.O. de , Marinho Jorge R. , Speit Günter , Erdtmann Bernardo
Published: April 2005

The main advantages of single-cell gel electrophoresis (SCG) are its applicability to any eukaryotic organism and cell type, its low cost and the short time required to obtain results. These properties make the SCG assay particularly useful in screening for environmental genotoxicity. The present study describes a modified version of this technique for use in field work with native rodents and examines some factors which influence the outcome of the assay. Wild rodents (Ctenomys torquatus, "tuco-tuco") from a region close to a strip coal mine and from a region with no coal mines were used. Animals from the coal mining region had significantly more DNA damage than those from the control area. The use of this SCG technique for direct sampling in the field should facilitate environmental genotoxicity studies with natural populations, without the need to remove the animals from their habitat or to sacrifice them.
X-linked adrenoleukodystrophy: clinical and laboratory findings in 15 Brazilian patients
Authors: Vargas Carmen R. , Coelho Daniella de M. , Barschak Alethéa G. , Souza Carolina F.M. de , Puga Ana C.S. , Schwartz Ida V.D. , Jardim Laura , Giugliani Roberto
Published: April 2005

Adrenoleukodystrophy (X-ALD) is an X-linked recessively inherited peroxisomal disorder, phenotypically heterogeneous, characterized by progressive white-matter demyelination of the central nervous system and adrenocortical insufficiency. We investigated 15 male X-ALD patients varying in age from 7 to 39, diagnosed among 108 suspected patients referred for investigation. Plasma levels of very long chain fatty acids (VLCFA) were measured at our laboratory using gas chromatography (GC). Eleven cases of childhood X-ALD and four cases of adrenomyeloneuropathy (AMN) were diagnosed. Adrenal leukodystrophy insufficiency and limb weakness were the most frequent symptoms, appearing in 12, 8 and 6 of the patients, respectively. Physician awareness of X-ALD seems inadequate to judge by age at diagnosis and lengthy interval between the start of symptoms and diagnosis. This is the first published series of Brazilian patients with X-ALD. We determined signs and symptoms relevant for diagnosis, as early identification seems important for treatment outcome. In addition, diagnosis identifies carriers, who could benefit from genetic counselling and prenatal diagnosis.
Fibroblasts of skin fragments as a tool for the investigation of genetic diseases: technical recommendations
Authors: Coelho Janice Carneiro , Giugliani Roberto
Published: April 2005

Skin biopsies are frequently indicated for investigation and/or confirmation of genetic disorders. Although relatively simple and noninvasive, these procedures require care in order to increase probability of success and to avoid patient discomfort and unnecessary repeated analyses and associated laboratory fees. The present report highlights the importance of skin biopsies in genetic disorder diagnosis and presents general rules for collecting, storing, transporting and processing samples. We recommend its reading to professionals intending to use this important and sometimes fundamental diagnostic tool.
Cockayne syndrome: report of a Brazilian family with confirmation of impaired RNA synthesis after UV-irradiation
Authors: Karam Simone M. , Costa Jaderson C. , Jardim Laura , Pires Ricardo F. , Lehmann Alan R. , Giugliani Roberto
Published: April 2005

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.
Human and medical genetics in Brazil
Authors: Beiguelman Bernardo
Published: April 2005

The present paper intends to be a brief historical analysis of the conditions for the development of Human and Medical Genetics in Brazil.
Phylogenetic correlograms and the evolution of body size in South American owls (Strigiformes)
Authors: Diniz-Filho José Alexandre Felizola , Sant'Ana Carlos Eduardo Ramos de
Published: April 2005

During the last few years, many models have been proposed to link microevolutionary processes to macroevolutionary patterns, defined by comparative data analysis. Among these, Brownian motion and Ornstein-Uhlenbeck (O-U) processes have been used to model, respectively, genetic drift or directional selection and stabilizing selection. These models produce different curves of pairwise variance between species against time since divergence, in such a way that different profiles appear in phylogenetic correlograms. We analyzed variation in body length among 19 species of South American owls, by means of phylogenetic correlograms constructed using Moran's I coefficient in four distance classes. Phylogeny among species was based on DNA hybridization. The observed correlogram was then compared with 500 correlograms obtained by simulations of Brownian motion and O-U over the same phylogeny, using discriminant analysis. The observed correlogram indicates a phylogenetic gradient up to 45 mya, when coefficients tend to stabilize, and it is similar to the correlograms produced by the O-U process. This is expected when we consider that body size of organisms is correlated with many ecological and life-history traits and subjected to many constraints that can be modeled by the O-U process, which has been used to describe evolution under stabilizing selection.
Electrophoretic characterization of Aspergillus nidulans strains with chromosomal duplications
Authors: Queiroz Marisa V. de , Pizzirani-Kleiner Aline Aparecida , Azevedo João Lúcio
Published: April 2005

Pulsed-field gel electrophoresis was used to characterize strains of Aspergillus nidulans with a chromosomal duplication Dp(I-II). Morphologically deteriorated and improved variants of these strains were also analyzed. The electrophoretic karyotype demonstrated that in two duplicated strains (A and B) the 4.2 Mb band, which corresponds to chromosome II, was absent and a new band was observed. Hybridization studies using the uapA (chromosome I) and wA (chromosome II) genes demonstrated that the new band corresponded to chromosome II plus the duplicated segment of chromosome I. The size of the chromosomal duplication was approximately 1.0 Mb. Analysis of the chromosomal bands of a morphologically improved strain showed that the duplicated segment of chromosome I was completely lost. The morphologically deteriorated variants V9 and V17 had the same karyotype as the duplicated strains. However, the deteriorated variant V5 lost part of chromosome I and had a rearrangement involving chromosome V. This rearrangement may have resulted from the mutagenic treatment used to obtain the genetic markers. Pulsed-field gel electrophoresis was found to be an excellent tool for locating chromosomal rearrangements.
Fast, non-toxic, and inexpensive n-butanol preparation of recombinant plasmids
Authors: Brieger Jürgen , Weidt Eberhard J. , Decker Jochen
Published: April 2005

Various commercial and non-commercial plasmid preparation protocols are currently available. However, the kits are expensive and many of the protocols contain toxic chemicals. Here we present a novel, optimized and, therefore, very advantageous plasmid preparation protocol using n-butanol. The preparation can be performed quickly and no toxic chemicals are used, at overall costs of about one cent per plasmid preparation.
Heat shock-induced apoptosis in germ line cells of Triatoma infestans Klug
Authors: Mello Maria Luiza S. , Maria Sílvya S. , Tavares Maria Cristina H.
Published: April 2005

The survival of Triatoma infestans and of somatic cells from this species is affected by heat shock. In this study, we examined the cell death responses of male germ line cells from 5th instar nymphs 7 and 30 days after heat shock exposure (40ºC, 1 h). The preparations were stained by the Feulgen reaction and the TUNEL immunocytochemical assay. Apoptosis was elicited by heat shock, with positive TUNEL responses in spermatogonial chromatin and chromosomes, spermatids and sperm cells. Spermatogonia were most affected seven days after the shock whereas some spermatids and sperm cells exhibited DNA fragmentation only thirty days after heat shock. The rate of cell death varied among the cells. In some cases, cellular differentiation was unaffected by heat shock, with DNA fragmentation occurring towards the end of spermatogenesis.