Three species of cichlids belonging to the genus Symphysodon have demonstrated interspecific and intraspecific variation in nucleolus organizer regions (NOR) detected with silver nitrate. In order understand evolution this marker genus, structural variability these sequences mitotic chromosomes from aequifasciatus, discus haraldi was investigated using both nitrate impregnation hybridization 18S rRNA gene probe. For three species, two markers were intraspecifically interspecifically variable...

As part of a genetic screening program for wild Discus fishes, we analyzed karyotypes and cytogenetic characteristics <i>Symphysodon aequifasciatus</i>, <i>S. discus</i> haraldi</i> using C-banding fluorescent in situ hybridization (FISH) with the <i>Rex</i>3 retrotransposon 5S rDNA probes mitotic meiotic chromosomes. In 3 species, diploid chromosome number was 2n = 60 contained predominantly meta-submetacentric showed blocks constitutive...

Four populations of Astyanax aff. fasciatus the upper rio Tibagi (municipal district Ponta Grossa, Paraná State, Brazil), had their karyotypes and morphometry analyzed. The cytogenetic data show occurrence distinct (cytotypes), here named cytotype A, with 2n=48 chromosomes (6m+18sm+14st+10a), B, 2n=50 (8m+18sm+14st+10a) C, (8m+18sm+14st+10a). distribution pattern constitutive heterochromatin was very similar between cytotypes A but diverged in relation to C. Distinct may occur sympatry...

Transposable elements (TEs) have the potential to produce broad changes in genomes of their hosts, acting as a type evolutionary toolbox and generating collection new regulatory coding sequences. Several TE classes been studied Neotropical cichlids; however, information gained from these studies is restricted physical chromosome mapping, whereas genetic diversity TEs remains unknown. Therefore, genomic organization non-LTR retrotransposons Rex1, Rex3, Rex6 five Amazonian cichlid species was...

Distribution of 6 microsatellites and 5 transposable elements on the chromosomes <i>Semaprochilodus taeniurus </i>and <i>S. insignis</i>, commonly referred to as Jaraqui, was performed using their physical mapping with fluorescence in situ hybridization. In this study, we aim understand evolutionary dynamics genomes <i>S</i>. <i>taeniurus</i> insignis</i> by comparing position, abundance contribution repetitive sequences origins...

Boids are primitive snakes from a basal lineage that is widely distributed in Neotropical region. Many of these species both morphologically and biogeographically divergent, the relationship among some remains uncertain even with evolutionary phylogenetic studies being proposed for group. For better understanding between snakes, we cytogenetically analysed 7 3 subspecies Boidae family using different chromosomal markers. The karyotypes Boa constrictor occidentalis, Corallus hortulanus,...

Cytogenetic analysis of the Amazon stingless bee Melipona seminigra merrillae, by conventional Giemsa staining and C-banding, revealed a different chromosome number for Melipona: 2n = 22 females diploid drones while haploid present n 11. There is no evidence B chromosomes. This result contrasts with previous studies, in which 19 species was determined as 18 9 males. Based on cytogenetic information available other species, we propose that M. s. merrillae has more derived number. indicates...

Karyotypes of six cichlid species the genus Crenicichla were investigated. The C. cincta, inpa, reticulata, lugubris, and cf. johanna collected from Amazon basin, britskii was Paraná-Paraguai basin. All analysed showed 2n = 48 chromosomes; however, johanna, had a karyotype formula 8M-SM+40ST-A, FN 56, while inpa reticulata exhibited 6M-SM+42ST-A, 54. Analysis active Ag-NORs revealed two NOR-bearing chromosomes in all species; theses cistrons located on different chromosome pairs and/or...

The structure and organization of repetitive elements in fish genomes are still relatively poorly understood, although most these believed to be located heterochromatic regions. Repetitive considered essential evolutionary processes as hotspots for mutations chromosomal rearrangements, among other functions - thus providing new genomic alternatives regulatory sites gene expression. present study sought characterize DNA sequences the Semaprochilodus insignis (Jardine & Schomburgk, 1841)...

Hypsiboas species have been divided into seven groups using morphological and genetic characters, but for most of the species, there is no cytogenetic information available. A analysis conventional staining, C-banding, silver fluorescence in situ hybridization (FISH) with telomeric sequence probes were used to investigate karyotype Amazon genus belonging following intrageneric groups: H. punctatus (H. cinerascens), semilineatus boans, geographicus, wavrini), albopunctatus lanciformis,...

Oecomys Thomas, 1906 is one of the most diverse and widely distributed genera within tribe Oryzomyini. At least sixteen species in this genus have been described to date, but it believed contains undescribed species. Morphological, molecular cytogenetic study has revealed an uncertain taxonomic status for several species, suggesting presence a complex The present work had goal contributing genetic characterization Brazilian Amazon. Thirty specimens were collected from four locations Amazon...

The genus Colomesus is the sole representative of family Tetraodontidae in Amazon region. Here, asellus was analyzed using conventional and molecular cytogenetic protocols. Its diploid chromosome number 2n = 46 with 12 meta-, 10 submeta-, 16 subtelo-, 8 acrocentric chromosomes a fundamental FN 84. An XX/XY sex system identified. Mapping 18S rDNA correlated nucleolus organizer regions (Ag-NORs) short arms 2 X females Y males. C-banding revealed heterochromatin centromeric all chromosomes,...

The Amazon aquatic ecosystems have been modified by the human population growth, going through changes in their water bodies and biota. spectacled alligator (Caiman crocodilus crocodilus) has a wide distribution adaptability to several environments, even those polluted ones. This study aimed investigate if Caiman species living urban streams of Manaus city (Amazonas State, Brazil) is affected environmental pollution. For that, it was used classical molecular cytogenetic procedures, addition...

Lizards of the family Teiidae (infraorder Scincomorpha) were formerly known as Macroteiidae. There are 13 species such lizards in Amazon, genera Ameiva (Meyer, 1795), Cnemidophorus (Wagler, 1830), Crocodilurus (Spix, 1825), Dracaena (Daudin, 1801), Kentropyx 1825) and Tupinambis 1802). Cytogenetic studies this group restricted to karyotype macrostructure. Here we give a compilation cytogenetic data Teiidae, including classic molecular analysis ameiva (Linnaeus, 1758), sp.1, calcarata...

The Amazon has abundant rivers, streams, and floodplains in both polluted nonpolluted environments, which show great adaptability. Thus, the goal of this study was to map repetitive DNA sequences mitotic chromosomes erythrocyte micronuclei tamoatás from environments assess possible genotoxic effects these environments. Individuals were collected Manaus, Amazonas (AM), submitted classical molecular cytogenetic techniques, as well a blood micronucleus test. Diploid number equal 60 are present...

Transposable elements have driven genome evolution and plasticity in many ways across a range of organisms. Different types biotic abiotic stresses can stimulate the expression or transposition these mobile elements. Here, we cytogenetically analyzed natural fish populations same species living under different environmental conditions to test influence organization transposable their genome. Differential behavior was observed for markers Rex 1, 3, 6 chromosomes individuals but coming from...