Willy Beçak, Maria Luiza Beçak,
... of Snakes in Short Term Cultures of LeucocytesWilly Becak, Maria Luiza Becak, and Heleneide R. S. NazarethWilly Becak Search for more articles by this author , Maria Luiza Becak Search for more articles by this author , and ... 185–236.https://doi.org/10.1007/BF00326193Maria Luiza Beçak, Willy Beçak, Franklin L. Roberts, Robert N. Shoffner, E. Peter Volpe, Kurt Benirschke, T. C. Hsu Boa constrictor amarali Stull, (Jan 1971): 101–103.https://doi.org/10.1007/978-3-662-38220-2_26N. O. Bianchi, W. Beçak, Martha S. A. de Bianchi, Maria L. Beçak, Maria N. Rabello Chromosome replication in ...
Tópico(s): Genomics and Phylogenetic Studies
1963 - University of Chicago Press | The American Naturalist
Produção Nacional
Willy Beçak, Maria Luiza Beçak, G. Schreiber, Delson Lavalle, Flàvia O. Amorim,
Fueron determinados por citofotometría los valores de DNA en 33 especies de Amphibia, en las que estaban incluidas 30 especies de Salientia, 1 de Gymnophiona y 2 de Caudata, y fueron comparadas con sus constituciones cromosomicas. Las variaciones encontradas sugieren que hubo aumento de DNA, independientemente, en las diferentes familias estudiadas y que en general, las especies más primitivas filogeneticamente, poseen menor cantidad de DNA, cuando comparadas a los valores encontrados para las más ...
Tópico(s): Genetic diversity and population structure
1970 - Birkhäuser | Experientia
Produção Nacional
Revisado por pares
Willy Beçak, Maria Luiza Beçak,
The karyotypes of 15 species of snakes are described: <i>Lachesis muta noctivaga</i>, <i>Micrurus lemniscatus carvalhoi</i>, <i>Philodryas aestivus aestivus</i>, <i>P. patagoniensis</i>, <i>P. serra</i>, <i>Thamnodynastes pallidus nattereri</i>, <i>T. strigatus</i>, <i>Tomodon dorsatus</i>, <i>Xenodon neuiviedii</i>, <i>Liophis miliaris</i>, <i>Erythrolamprus aesculapii venustissimus</i>, <i>Hydrodynastes bicinctus ...
Tópico(s): Chromosomal and Genetic Variations
1969 - Karger Publishers | Cytogenetic and Genome Research
Willy Beçak, Maria Luiza Beçak, Shigeo Ohno,
Of 30 adult specimens of green sunfish, <i>Lepomis cyanellus</i>, obtained from a fish farm in southern California, 16 were heterozygous for a single Robertsonian translocation while 12 carried no translocation; the remaining two were homozygous for a translocation. In each heterozygote, the three cell types coexisted: the original heterozygous set (2n = 47, one metacentric) and the two homozygous sets (2n = 48, no metacentric, and 2n = 46, two metacentrics). No intraindividual chromosomal polymorphism ...
Tópico(s): Animal Genetics and Reproduction
1966 - Karger Publishers | Cytogenetic and Genome Research
Produção Nacional
Revisado por pares
B J Schmidt, Willy Beçak, Maria Luiza Beçak, Isaac Soibelman, Antonio da Silva Queiroz, Antonio Paulo Lorga, F Secaf, Carla António, Azarias de Andrade Carvalho,
The clinical, pathologic, and laboratory findings of a patient with severe metaphyseal dysostosis are described and the literature reacting to this disorder is reviewed. Chromosomal analysis suggests that some cells with trisomy for chromosome 16 may be present in this patient. Therapy with massive doses of vitamin D parenterally failed to influence the roentgenographic changes in the metaphyses. The clinical, pathologic, and laboratory findings of a patient with severe metaphyseal dysostosis are ...
Tópico(s): Nuclear Structure and Function
1963 - Elsevier BV | The Journal of Pediatrics
Produção Nacional
Revisado por pares
Willy Beçak, Maria Luiza Beçak, H. R. S. Nazareth,
Karyotypic studies have been made of two species of South American snakes, <i>Boa constrictor amarali</i> and <i>Bothrops jararaca</i>. Both have 36 chromosomes; 16 macrochromosomes and 20 microchromosomes. While no morphological difference is discernible between the mitotic chromosome complements of the male and the female <i>Boa constrictor amarali</i>, a heteromorphic pair is evident in the female <i>jararaca</i>, in which the subterminal W is distinctly smaller ...
Tópico(s): Mosquito-borne diseases and control
1962 - Karger Publishers | Cytogenetic and Genome Research
Produção Nacional
Revisado por pares
N. O. Bianchi, Willy Beçak, Martha S. Bianchi, Maria Luiza Beçak, Maria Nazareth Rabello,
Tópico(s): Chromosomal and Genetic Variations
1969 - Springer Science+Business Media | Chromosoma
... Stenius, Christina, Christian, L. C., Beçak, W. and Beçak, Maria Luiza 1964. Chromosomal uniformity in the avian subclass Carinatae. ...
Tópico(s): Plant Reproductive Biology
2009 - BioMed Central | Hereditas
Produção Nacional
Revisado por pares
Willy Beçak, Maria Luiza Beçak, J.D. Andrade, A Manissadjian,
Tópico(s): Vascular Malformations Diagnosis and Treatment
1963 - Elsevier BV | The Lancet
Produção Nacional
Willy Beçak, Maria Luiza Beçak,
En los ofídios, las hembras presentan, en los núcleos interfásicos teñidos por la quinacrina, un corpúsculo fluorescente brillante. Este coincide con él condensado heteropicnótico de preparaciones comunes y corresponde al cromosoma W. Sin enbargo, él W no presenta fluorescencia intensa en las metafases somaticas.
Tópico(s): Animal Genetics and Reproduction
1972 - Birkhäuser | Experientia
Produção Nacional
Revisado por pares
Maria Luiza Beçak, Willy Beçak,
Polyploidy is an important mechanism of evolution in lower vertebrates, resulting in gene duplication and loci duplication evolving to diploidization. In polyploid anurans DNA is increased, but RNA and protein synthesis is kept at the same levels as in their diploid counterparts. Recent cytogenetic findings in <i>Odontophrynus americanus</i> show: (1) amphiplasty and asynchrony of the cell division cycle in 4n and (2) intra- and interindividual alterations of chromosome 4 morphology in 4n ...
Tópico(s): Advanced biosensing and bioanalysis techniques
1998 - Karger Publishers | Cytogenetic and Genome Research
Produção Nacional
Revisado por pares
R.F. Batistic, Mitithaka Soma, Maria Luiza Beçak, Willy Beçak,
Journal Article Further Studies on Polyploid Amphibians: A diploid population of Phyllomedusa burmeisteri Get access R. F. BATISTIC, R. F. BATISTIC Serviço de Genética, Instituto) ButantanC. Postal 65, Säo Paulo, Brazil Search for other works by this author on: Oxford Academic PubMed Google Scholar M. SOMA, M. SOMA Serviço de Genética, Instituto) ButantanC. Postal 65, Säo Paulo, Brazil Search for other works by this author on: Oxford Academic PubMed Google Scholar M. L. BEÇAK, M. L. BEÇAK Serviço ...
Tópico(s): Amphibian and Reptile Biology
1975 - Oxford University Press | Journal of Heredity
Produção Nacional
Maria Luiza Beçak, Willy Beçak,
Tópico(s): Chromosomal and Genetic Variations
1974 - Birkhäuser | Experientia
Maria Luiza Beçak, Willy Beçak,
Based on the geographical distribution and karyotypes, in particular on satellite localization and number in the various species of Odontophrynus, a hypothetical phylogeny for this genus of anurans is suggested. Tetraploid 0. americanus could have originated by autopolyploidy from the diploid 0. americanus. These populations are already isolated to such an extent that both may be considered different species.
Tópico(s): Genomics and Phylogenetic Studies
1974 - The Society for the Study of Amphibians and Reptiles | Journal of Herpetology
Produção Nacional
Revisado por pares
Maria Luiza Beçak, Willy Beçak, Leonor Denaro,
SUMMARYA comparative cytogenetic study was done on ten lacertilian species belonging to six families: Iguanidae, Teiidae, Amphisbaenidae, Gekkonidae, Anguidae and Scincidae.Intra-individual and intrapopulational karyotype variations apparently stemming from differences in the number of chromosomes were observed in the iguanid Tropidurus torquatus from Minas Gerais and Maranhão. A heteromorphic autosomal pair was found in another population (São Paulo) of the same species. The geographical variation ...
Tópico(s): Amphibian and Reptile Biology
1972 - University of Florence | Caryologia
Produção Nacional
Maria Luiza Beçak, Willy Beçak, Luiz Dino Vizotto,
La ocurrencia de poliploidia ha sido relatada en anuros de la familia Ceratophrydidae incluyendo la especie tetraploideO. americanus (4n=44). En una área geográfica distinta, sin embargo, fue observada una población diploide deO. americanus (2n=22). Fueron obtenidos híbridos intraespecíficos triploides (3n=33) por cruzamiento de ejemplares diploides y tetraploides deO. americanus.
Tópico(s): Turtle Biology and Conservation
1970 - Birkhäuser | Experientia
Produção Nacional
Revisado por pares
Maria Luiza Beçak, Leonor Denaro, Willy Beçak,
Polyploid species were described in amphibians of the family Ceratophrydidae (Procoela). Tetraploid (4N = 44) and octoploid (8N = 104) karyotypes resulted apparently by duplication of ancestral genomes with N = 11 and N = 13 respectively. The meiosis of the polyploid species was regular, producing euploid gametes. Comparative cytophotometric measurements confirmed a DNA increase in a 1:2:4 ratio, as expected from cytological observations. Fourteen species and one subspecies of the families Ceratophrydidae, ...
Tópico(s): Genetic diversity and population structure
1970 - Karger Publishers | Cytogenetic and Genome Research
Produção Nacional
Revisado por pares
SUMMARYKaryotypes of eighteen species of Anura from Brazil have been studied (Bufonidae, Leptodactylidae, Hylidae, and Pseudidae).Leptodactylidae show a variation of chromosomal number from 2 n = 18 to 2 n = 26. Hylidae presents also variations from 2 n = 22 to 2 n = 30. These differences were correlated to morphological alterations of the karyotypes. Bufonidae, however, disclosed a great chromosomal uniformity, showing the same diploid number, 2 n = 22. In Pseudidae one species showed 2 n = 24 chromosomes. ...
Tópico(s): Aquaculture disease management and microbiota
1968 - University of Florence | Caryologia
Produção Nacional
Revisado por pares
Maria Luiza Beçak, Willy Beçak, Alexandre da Costa Pereira,
The positioning of macrochromosomes of Bothrops jararaca and Bothrops insularis (Viperidae) was studied in undistorted radial metaphases of uncultured cells (spermatogonia and oogonia) not subjected to spindle inhibitors. Colchicinized metaphases from uncultured (spleen and intestine) and cultured tissues (blood) were also analyzed. We report two antagonic non-random chromosome arrangements in untreated premeiotic cells: the parallel configuration with homologue chromosomes associated side by side in ...
Tópico(s): Turtle Biology and Conservation
2003 - Brazilian Academy of Sciences | Anais da Academia Brasileira de Ciências
Produção Nacional
Revisado por pares
Willy Beçak, Maria Luiza Beçak, J.D. Andrade,
Tópico(s): Pediatric Pain Management Techniques
1964 - Karger Publishers | Human Heredity
Produção Nacional
Willy Beçak, Arno Rudi Schwantes, Maria Luiza B. Schwantes,
Abstract Utilizing starch gel electrophoresis, a study was made on the albuminlike plasma protein of a tetraploid South American species of frog. No allelic polymorphism at this locus was indicated in the congeneric diploid species O. cultripes , but five distinct electrophoretic phenotypes were encountered among 141 frogs of the tetraploid species O. americanus . These included two homozygous types each with a single distinctive albumin‐like band, and three heterozygous types. The three heterozygotes ...
Tópico(s): Mosquito-borne diseases and control
1968 - Wiley | Journal of Experimental Zoology
Produção Nacional
Revisado por pares
This article reviews the polyploidy events that have long been demonstrated to play a role in the evolution of Anura, while also discussing the importance of epigenetic control of gene expression and diversity.Findings on Brazilian autopolyploid anurans, mainly of the genus Odontophrynus, obtained in previous studies on their cytogenetics, chromatin ultrastructure, and molecular gene regulation are discussed here.Our data on genome duplication and on epigenetic events were analyzed here regarding ...
Tópico(s): Genetic diversity and population structure
2014 - Research Foundation of Ribeirão Preto | Genetics and Molecular Research
Produção Nacional
Metaphasechromosome lassen nach Chloroform-Behandlung eine Aufteilung in Halbchromatide erkennen. Zytologische Befunde der Untersuchungen (Licht- und Elektronen-Mikroskop) weisen auf eine binemische Struktur des eukaryotischen Chromosoms hin.
Tópico(s): Biopolymer Synthesis and Applications
1974 - Birkhäuser | Experientia
Isa Trajtengertz, Maria Luiza Beçak, Itamar R. G. Ruiz,
The ribosomal cistrons of six subspecies of Bothrops neuwiedi (Serpentes) were studied at both the cytogenetic and molecular levels. These subspecies populations occur in several Brazilian regions. The analysis of the nucleolar organizing region banding patterns showed variability in the chromosomal localization of rDNA cistrons. The rDNA clusters were found in two microchromosomes, in chromosome pair Number 6, or even in the one homologue of chromosome 6, and one microchromosome, according to the ...
Tópico(s): Identification and Quantification in Food
1995 - NRC Research Press | Genome
Produção Nacional
Maria Luiza Beçak, Willy Beçak,
Tópico(s): Genomics and Phylogenetic Studies
1972 - Birkhäuser | Experientia
Produção Nacional
A. Brunner, A. R. Schwantes, Maria Luiza B. Schwantes, Willy Beçak,
Es wurde das Vorkommen von Haemoglobin in mitochondrienähnlichen Organellen unreifer Erythrocyten aus peripherem Kaninchenblut elektrophoretisch aus der abgetrennten Franktion nachgewiesen und ergänzt durch elektronenoptische Beobachtungen an Dünnschnitten ganzer Retikulozyten. Für die Organellen wird die Bezeichnung ≪Hemosome≫ vorgeschlagen.
Tópico(s): Hemoglobinopathies and Related Disorders
1972 - Birkhäuser | Experientia
Produção Nacional
Revisado por pares
Willy Beçak, Maria Luiza Beçak, J.D. Andrade, A Manissadjian,
The presence of a translocation 21/13-15 is related in 46 chromosomes, karyotypes of a mongoloid male child (Down's syndrome). The abnormal chromosome was transmitted by the mother of the patient. The possible deficiency of translocated chromosome 21 and the possible origin of the anomaly in the family was discussed and the presence of a markedly large Y chromosome in the karyotypes of the patient as in those of his father was also noted.
Tópico(s): Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
1963 - Thieme Medical Publishers (Germany) | Arquivos de Neuro-Psiquiatria
Shigeo Ohno, Maria Luiza Beçak,
The amino- and carboxyl-terminal regions of H1 histone are afforded an opportunity to bind to their own coding segments. While such binding is of no consequence to the type of H1 histone that is expressed only in terminally differentiated cells (here referred to as H5), the same binding occurring in H1 of proliferating cells might affect the course of evolution of its amino- and carboxyl-terminal regions. With the above in mind, amino acid sequences of H5 from three species were compared with those ...
Tópico(s): Biotin and Related Studies
1993 - National Academy of Sciences | Proceedings of the National Academy of Sciences
Produção Nacional
Maria Luiza Beçak, Kei Fukuda,
Condensed chromatin shows globules of 300 A formed by approximately 8 to 10 nucleosomes. Each globule might be an uncoiled turn of a supercoil. This supercoil forms major coils along the fibre.
Tópico(s): DNA and Nucleic Acid Chemistry
1979 - Birkhäuser | Experientia
Produção Nacional
Revisado por pares
N. Leon, Willy Beçak, Maria Luiza Beçak, Dorfman Ri,
Tópico(s): Sympathectomy and Hyperhidrosis Treatments
1963 - Karger Publishers | Human Heredity