|
|
|
Registros recuperados: 50 | |
|
| |
|
|
Amar,Gabriel; Palma Rojas,Claudio; von Brand,Elisabeth; Jara-Seguel,Pedro. |
Mesodesma donacium is a marine clam distributed from Sechura Bay (5°S) in northern Perú to Chiloé Island (43ºS) in southern Chile. Due to the commercial importance of this species, their populations have been reduced in the later years. In this work the karyotype morphology of M. donacium is described for the first time, to be additional to taxonomical, ecological, morphological, and reproductive antecedents previously documented for the species. M. donacium shows a diploid karyotype 2n = 38 with one metacentric, fifteen submetacentric and three subtelocentric chromosome pairs. The total haploid set length was 42.4 mm, and the mean chromosome size was 2.2 mm. M. donacium showed similitude in chromosome number with other species of the Veneroida order, but... |
Tipo: Journal article |
Palavras-chave: Veneroida; Mesodesmatidae; Cytogenetic relationshipt; Chromosomes; Karyotype morphology. |
Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382008000100003 |
| |
|
| |
|
|
Milhomem,Susana Suely Rodrigues; Souza,Augusto Cesar Paes de; Nascimento,Aline Lira do; Carvalho Jr.,Jaime Ribeiro; Feldberg,Eliana; Pieczarka,Julio Cesar; Nagamachi,Cleusa Yoshiko. |
We studied the karyotypes of Hassar cf. orestis and an undescribed Hassar species from the Jarí River and Opsodoras ternetzi, H. orestis and Platydoras cf. costatus from the Xingú River, all with 2n = 58. Constitutive heterochromatin is located in the centromere in most metacentric pairs; in some chromosomes this banding is not present, or it is located on the whole chromosome arm or in the distal regions. The NOR is located on a single biarmed pair at a distal region of the short arm in H. cf. orestis, H. orestis and P. cf. costatus at a distal region of the long arm in O. ternetzi and at a proximal region of the long arm in the Hassar species. In all species (except for Hassar sp.) the CMA3 analysis revealed a rich G-C region coincident with the NOR.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosomes; Amazon; Biodiversity; Siluriformes; Banding; Fluorochromes. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200017 |
| |
|
|
Noleto,Rafael Bueno; Kantek,Daniel Luis Zanella; Swarça,Ana Cláudia; Dias,Ana Lúcia; Fenocchio,Alberto Sergio; Cestari,Marta Margarete. |
We present the karyotypic characterization of 26 specimens of the side-necked turtle Hydromedusa tectifera collected in the upper Iguaçu River, Paraná state, Brazil. The turtles were cytogenetically analyzed using Giemsa staining and other banding techniques (C, G, Ag-NOR and CMA3) as well as fluorescence in situ hybridization (FISH) with a rDNA 18S probe. All the specimens showed a diploid number of 58 composed of 22 macro and 36 microchromosomes. The Ag-NOR, CMA3 and FISH techniques permitted the identification and characterization of the chromosome pairs bearing nucleolus organizer regions (NORs), while G-banding facilitated a better recognition and pairing of macrochromosomes. These data agree with some information available in the literature and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosomes; FISH; G-banding; Pleurodira; Turtle. |
Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000200011 |
| |
|
| |
|
|
Nogueira,Lídia; Zanoni,Juliani Bruna; Solé,Mirco; Affonso,Paulo Roberto Antunes de Mello; Siqueira,Sérgio; Sampaio,Iracilda. |
Scinax species are still underrepresented in cytogenetic studies, mainly with respect to populations from northeastern and northern Brazil. In this study, we provide new chromosomal information on Scinax boesemani, S. camposseabrai, S. garbei, S. pachycrus, S. trilineatus and S. x-signatus, all belonging to clade S. ruber. They were collected at two locations in the Caatinga biome (northeastern Brazil) and at one in the Amazon (northern Brazil) biomes. Chromosomes were analyzed by conventional staining, C-banding, Ag-NOR staining, and fluorochrome staining. All species shared a modal diploid value of 2n = 24 and fundamental arm number (FN) of 48. Moreover, both chromosomal size and morphology were similar to other species in this Scinax clade. C-banding... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amphibians; Chromosomes; Fluorochromes; Heterochromatin; RDNA. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572015000200156 |
| |
|
|
Martinez,Emanuel Ricardo Monteiro; Nirchio,Mauro; Granado,Angel; Foresti,Fausto; Oliveira,Claudio. |
Cytogenetic analyses performed in Cephalosilurus apurensis, Microglanis aff. cottoides and Pseudopimelodus bufonius revealed that the three species have 2n = 54 chromosomes: C. apurensis presented six metacentric (M), 28 submetacentric (SM), 14 subtelolocentric (ST), and six acrocentric (A) chromosomes, while M. aff. cottoides showed 10M, 32SM, 10ST and 2A, and P. bufonius had 12M, 30SM and 12ST. The nucleolus organizer regions (NORs) were present on the short arm of a middle-sized ST pair, identified as pair 19, in C. apurensis NORs were found on the short arm of a middle-sized ST (pair 23) and on the long arm of a middle-sized ST (pair 22) in M. aff. cotttoides and on the short arm of three middle-sized ST pairs, identified as pairs 9, 10 and 11, in P.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Karyotype; Chromosomes; C-banding; Ag-NOR; Fish. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000400015 |
| |
|
| |
|
|
Ghigliotti,Laura; Mazzei,Federico; Ozouf-Costaz,Catherine; Christiansen,Jørgen S.; Fevolden,Svein-Erik; Pisano,Eva. |
The capelin, Mallotus villosus (Osmeriformes, Osmeridae), is an ecological and commercial key component of the sub-arctic ichthyofauna. Here, we provide the first cytogenetic information on the species based on both conventional karyotyping and chromosomal mapping of 45S and 5S ribosomal genes through fluorescence in situ hybridization (FISH). The capelin genome displayed a diploid number of 54 with the karyotypic formula 26m/sm+28st/a and a fundamental number (FN) = 80. Both classes of ribosomal genes appeared to be spread out to multiple chromosomal locations, i.e. the 45S and 5S rDNA clusters were detected on six and seven chromosome pairs, respectively. A linked chromosomal organization of the major and minor ribosomal genes classes has been visualized... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Capelin; Chromosomes; Osmeridae; Ribosomal genes. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200003 |
| |
|
|
Fagundes,Valéria; Christoff,Alexandre Uarth; Amaro-Ghilard,Renata Cecília; Scheibler,Daniel R.; Yonenaga-Yassuda,Yatiyo. |
This is the first time the karyotype of the Brazilian squirrel Sciurusaestuans ingrami, with 2n = 40, is described. The karyotype of this species comprises 18 pairs of biarmed and one minute pair of acrocentric autosomes, a medium-sized submetacentric X and a medium-sized acrocentric Y. Four pairs have an interstitial secondary constriction, co-located with nucleolar organizer regions (NORs), identified by silver-staining technique and fluorescent in situ hybridization (FISH) with ribosomal 18S/28S probes. The occurrence of multiple interstitial NORs is rare in rodents, and this is one of the few examples, identified by a molecular cytogenetics approach. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Squirrels; Chromosomes; Karyotype; NORs; Rodentia. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000300007 |
| |
|
|
Guarido,Paula Carolina Paes; Paula,Adriano Alves de; Silva,Carlos Roberto Maximiano da; Rodriguez,Carmen; Vanzela,André Luís Laforga. |
Heterochromatin comprises a fraction of the genome usually with highly repeated DNA sequences and lacks of functional genes. This region can be revealed by using Giemsa C-banding, fluorochrome staining and cytomolecular tools. Some plant species are of particular interest through having a special type of heterochromatin denominated the cold-sensitive region (CSR). Independent of other chromosomal regions, when biological materials are subjected to low temperatures (about 0 °C), CSRs appear slightly stained and decondensed. In this study, we used Cestrum strigilatum (Solanaceae) to understand some aspects of CSR condensation associated with cytosine methylation levels, and to compare the behavior of different heterochromatin types of this species, when... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anti-5-methylcytosine; Cestrum; Chromosomes; CMA/DAPI banding; Heterochromatin; Immunolabeling. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000300012 |
| |
|
|
Pereira Júnior,Hélio Rubens Jacintho; Jorge,Wilham; Costa,Maria Elvira Loyola Teixeira da. |
Anteaters belong to the Order Xenarthra / Family Myrmecophagidae and are the only members without teeth. There are three genera with four living species in the family Myrmecophagidae: Myrmecophaga tridactyla (giant anteater), Tamandua tetradactyla (southern lesser anteater), Tamandua mexicana (northern lesser anteater), and Cyclopes didactylus (silky anteater). The karyotypes of M. tridactyla (2n = 60), T. tetradactyla (2n = 54) and C. didactylus (2n = 64) have already been described. In the present paper, three female and two male specimens of giant anteater and one lesser anteater male were analyzed. The results indicate the existence of a new karyotype in the genus Tamandua, with 2n = 56 chromosomes, which can represent a new lesser anteater species.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anteater; Chromosomes; Myrmecophagidae. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000300014 |
| |
|
|
Martinez,Emanuel Ricardo Monteiro; Zawadzki,Claudio Henrique; Foresti,Fausto; Oliveira,Claudio. |
In this work, we analyzed the karyotypes of five species. Hypostomus cf. heraldoi, from the Mogi-Guaçu River, had 2n = 72 chromosomes, with a nucleolar organizer region (NOR) in one chromosomal pair. Hypostomus regani, from the Mogi-Guaçu River had 2n = 72 chromosomes with NORs in two chromosomal pairs. Hypostomus sp., from the Mogi-Guaçu River basin, had 2n = 68 chromosomes, with NORs in two chromosomal pairs. Hypostomus aff. agna, from Cavalo Stream, had 2n = 74 chromosomes with NORs in two chromosomal pairs. Hypostomus cf. topavae, from Carrapato Stream, had 2n = 80 chromosomes, with NORs in two chromosomal pairs. Hypostomus species showed marked diversity in the karyotypic formula, which suggested the occurrence of several Robertsonian rearrangements... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosomes; Evolution; Hypostominae; Neotropical fish; NOR. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000400006 |
| |
|
| |
|
| |
|
| |
|
|
Bouilly, Karine; Bonnard, Marc; Grouhel, Stephanie; Lapegue, Sylvie. |
Divers travaux menés depuis 1984 montrent qu’il existe, chez l’huître creuse Crassostrea gigas, des cellules présentant un nombre anormal de chromosomes (2n = 19, 18 ou même 17 au lieu de 2n = 20). Or, une corrélation négative entre l’aneuploïdie somatique et le taux de croissance a été décrite à de nombreuses reprises (Thiriot-Quiévreux et al., 1988, 1992 ; Leitão et al., 2001a ; Zouros et al., 1996). Bien que les causes environnementale et /ou génétique de l’aneuploïdie restent encore largement inconnues, des études récentes ont permis de poser l’hypothèse d’une base génétique large dans la détermination de ce caractère (Leitão et al., 2001b). De plus, un effet toxique direct de l’atrazine (herbicide couramment utilisé dans la région) sur le génome d’une... |
Tipo: Text |
Palavras-chave: Génétique; Chromosomes; Aneuploïdie; Huîtres creuses; Crassostrea gigas. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00044/15476/12855.pdf |
| |
|
|
Lapegue, Sylvie; Mccombie, Helen; Leitao, Alexandra; Bouilly, Karine; Sabatier, Sebastien; Heurtebise, Serge; Boudry, Pierre; Thiriot Quievreux, Catherine; Gerard, Andre. |
Divers travaux menés depuis 1984 montrent qu’il existe, chez l’huître creuse Crassostrea gigas, des cellules montrant un nombre anormal de chromosomes (2n = 19, 18 ou même 17 au lieu de 2n = 20). Le niveau d’aneuploïdie est déterminé par le décompte des chromosomes à partir de suspensions cellulaires de tissu branchial. Le pourcentage de cellules aneuploïdes est toujours significativement supérieur dans les "lots de queue", c'est-à-dire les huîtres présentant des croissances plus faibles, et peut atteindre plus de 30 %. Récemment, une étude réalisée au sein du programme européen « Genephys » a démontré que plus de 50 % de la variance pour la vitesse de croissance était liée au taux d’aneuploïdie. Cependant, de nombreux points concernant ce phénomène... |
Tipo: Text |
Palavras-chave: Génétique; Chromosomes; Aneuploïdie; Huîtres creuses; Crassostrea gigas. |
Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00043/15474/12853.pdf |
| |
|
|
Bouilly, Karine; Bonnard, Marc; Lapegue, Sylvie. |
Des anomalies cytogénétiques, telles que l'aneuploïdie, sont connues pour être communes chez les bivalves (Ahmed et Sparks, 1970; Dixon, 1982; Thiriot- Quiévreux, 1986; Martínez-Expósito et al., 1992; Li et Havenhand, 1997). Ce phénomène, qui a pour origine principalement une non-disjonction des chromosomes pendant la mitose ou la méiose (Bond et Chandley, 1983; Martin et Rademaker, 1990), est souvent létal chez les animaux supérieurs tels que les mammifères ou bien associé à un retard de croissance (Vig et Sandberg, 1987). Chez Crassostrea gigas, l’aneuploïdie est l’altération du nombre diploïde normal de 20 chromosomes (Ahmed et Sparks, 1967; Thiriot-Quiévreux, 1984) en cellules hypodiploïdes avec 19, 18 ou 17 chromosomes (Thiriot-Quiévreux et al.,... |
Tipo: Text |
Palavras-chave: Génétique; Chromosomes; Aneuploïdie; Huîtres creuses; Crassostrea gigas. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/00044/15477/12856.pdf |
| |
Registros recuperados: 50 | |
|
|
|