The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Fish eyes possess a complicated morphological and neural organisation of retinal and extra-retinal receptors. Features such as photoreceptor mosaic array and photoreceptor grouping are unique among vertebrates. Spectral sensitivities of these photoreceptors range from UV to the red portion of the visible spectrum. Moreover, these sensitivities can change with the age of the animals. In this review...
Spermatocyte chromosomes of the slug Milax nigricans (Mollusca: Gastropoda: Pulmonata) were studied using silver staining (Ag-NOR) and fluorescent in situ hybridization (FISH) with four repetitive DNA probes [18S rDNA, 5S rDNA, (TTAGGG) n and (GATA) n ]. Silver impregnation was inadequate to localize the chromosome sites of nucleolus organizer regions (NORs) since no silver dots occurred...
Comparative cytogenetic analyses were carried out in six species of Brachycephalidae from southeastern Brazil. Barycholos ternetzi, Eleutherodactylus binotatus, Eleutherodactylus guentheri, Eleutherodactylus juipoca, Eleutherodactylus parvus and Eleutherodactylus sp. have 2n=22 karyotypes with a marked variation in the morphology of chromosome pairs 8, 10 and 11, which are of telocentric or metacentric...
Repetitive DNAs have been extensively applied as physical chromosome markers on comparative studies, identification of chromosome rearrangements and sex chromosomes, chromosome evolution analysis, and applied genetics. Here we report the characterization of repetitive DNA sequences from the Nile tilapia (Oreochromis niloticus) genome by construction and screening of plasmid library enriched with repetitive...
We studied the karyotypes of 35 Sternopygus macrurus fishes of four localities from rivers of the Eastern Amazon basin. In these four places the karyotypes have 2n=46 chromosomes, NF=92, where 30 are metacentric (M) and 16 submetacentric (SM). The constitutive heterochromatin (CH) is found in the centromeric region of most chromosomes and in the pericentromeric region of pairs 5, 17 and 19. Pair 1...
New karyotypic data are presented for the Astyanax fasciatus species complex from four different locations on the Upper Tibagi River in the state of Paraná, Brazil. Chromosome markers were analyzed using conventional (Ag-NOR) and molecular (FISH with 18S biotinylated probes) methods. Two cytotypes were found in cell counts with diploid number 2n=48 chromosomes and 2n=50 chromosomes, previously denominated...
Skeletal muscle is the edible part of the fish. It grows by hypertrophy and hyperplasia, events regulated by differential expression of myogenic regulatory factors (MRFs). The study of muscle growth mechanisms in fish is very important in fish farming development. Pacu (Piaractus mesopotamicus) is one of the most important food species farmed in Brazil and has been extensively used in Brazilian aquaculture...
Chloride cells are responsible for ionic exchanges in the fish gill. These cells have been widely studied, considering its importance in vital functions of the gill, and because they proliferate when exposed to unfavorable environments. One of the main characteristic of these cells is an acidic cytoplasm, which has been used for identification through histochemical techniques with dyes such as Toluidine...
Conventional chromosome staining has suggested that more than 75% of the tomato chromosomes are constituted by heterochromatin. In order to determine whether more deeply stained proximal regions are classic heterochromatin, the distributions of C-bands and chromomycin A 3 (CMA) bands, and the prophase condensation patterns, were analysed in tomato. In this and most other species of the tomato...
The family Ariidae comprises approximately 130 catfish species on both warm-temperate and tropical continental shelves around the world. The systematics of the group is problematic, with several misidentification problems. In order to better understand the evolutionary relationships in the family, the present study used a cytogenetic approach to characterize two populations of Genidens genidens and...
Alticinae has the greatest amount of biodiversity among the Chrysomelidae, with 40,000 described species, only 290 of which have been analyzed cytogenetically. The majority of studies refer to conventional staining and few species have been analyzed or have responded to differential staining methods. The aim of the present study was to describe an 18S rDNA probe for Alticinae and the location of this...
The increasing need for renewable energy resources has led to higher demands for biofuel, a scenario where the castor bean (Ricinus communis L.) seed oil represents a promising source of raw material. Despite that, information regarding the genome organization of R. communis is still scarce, impairing the application of modern biotechnological and breeding procedures. The present work brings the first...
The Coleopterans of Scarabaeinae clade presents Coprophanaeus (Megaphanaeus) ensifer and C. (Coprophanaeus) cyanescens (Scarabaeidae) when they are studied cytogenetically by different techniques. The species present symmetric karyotypes, diploid number of 2n=20, and meta-submetacentric chromosomes. C. (M.) ensifer present an XY sex-determining mechanism and C. (C.) cyanescens an XY p parachute...
Characterization of the major (18S) and minor (5S) ribosomal RNA genes were carried out in three commercially important Indian major carp (IMC) species, viz. Catla catla, Labeo rohita and Cirrhinus mrigala along with their physical localizations using dual colour fluorescence in situ hybridization. The diploid chromosome number in the above carps was confirmed to be 50 with inter-species karyo-morphological...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.