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Identification of a new repetitive element in the sex chromosomes of Leporinus elongatus (Teleostei : Characiformes : Anostomidae): new insights into the sex chromosomes of Leporinus
(Karger, 2007-01-01)
Leporinus elongatus represents an interesting model for studies on chromosome evolution since it possesses a conspicuous ZZ/ZW sex chromosome system that has been characterized mainly by basic cytogenetic techniques. In ...
Chromosome studies in some Stevia. Cav. (Compositae) species from Southern Brazil
(Sociedade Brasileira de Genética, 1996-01-01)
Karyotypes of six species of the genus Stevia from Southern Brazil were studied, utilizing root tip metaphases. All species were diploid with 2n = 22 chromosomes. It was possible to identify each species by chromosome ...
Molecular cytogenetic analysis of heterochromatin in the chromosomes of tilapia, Oreochromis niloticus (Teleostei : Cichlidae)
(Kluwer Academic Publ, 1998-04-01)
The structure of the heterochromatic bands in mitotic chromosomes of the important tropical aquaculture species of tilapia, Oreochromis niloticus, was investigated by the combination of the C-banding technique, chromosomal ...
Chromosome analysis of two species of sugar cane pests of the genus Mahanarva (Homoptera, Cercopidae)
(2002-10-01)
Studies on the cytogenetics of Homoptera are scarce. Some references in the literature have reported a chromosome number for the genus ranging from n=5 to 19 and 2n=10 to 2n=39 chromosomes. The genus Mahanarva includes two ...
Chromosomal Mapping of Repetitive DNAs in the Grasshopper Abracris flavolineata Reveal Possible Ancestry of the B Chromosome and H3 Histone Spreading
(2013-06-27)
Supernumerary chromosomes (B chromosomes) occur in approximately 15% of eukaryote species. Although these chromosomes have been extensively studied, knowledge concerning their specific molecular composition is lacking in ...
Are NORs Always Located on Homeologous Chromosomes? A FISH Investigation with rDNA and Whole Chromosome Probes in Gymnotus Fishes (Gymnotiformes)
(2013-02-06)
Gymnotus (Gymnotiformes, Gymnotidae) is the most diverse known Neotropical electric knife fish genus. Cytogenetic studies in Gymnotus demonstrate a huge karyotypic diversity for this genus, with diploid numbers ranging ...
Morphologically differentiated sex chromosomes in neotropical freshwater fish
(2001-12-01)
A general survey of the occurrence of morphologically differentiated sex chromosomes in the neotropical freshwater fishes is presented. The total number of 32 occurrences involving simple XX-XY and ZZ-ZW, and multiple ...
Conventional and ultrastructural analyses of the chromosomes of Discocyrtus pectinifemur (Opiliones, Laniatores, Gonyleptidae)
(Wiley-Blackwell Publishing, Inc, 2009-05-01)
Among the Opiliones, species of the suborders Cyphophthalmi, Eupnoi, Dyspnoi and Laniatores have shown very diverse diploid chromosome numbers. However, only certain Eupnoi species exhibit XY/XX and ZZ/ZW sex chromosome ...
Chromosomal location of heterochromatin and 45S rDNA sites in four South American triatomines (Heteroptera: Reduviidae)
(Zoological Inst, 2010-01-01)
The Triatominae are distributed in Brazilian regions and are the vector of Chagas disease. This group is also characterized by lower karyotype variability, occurrence of holokinetic chromosomes and inverted meiosis of the ...