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Addressing Long-Standing Questions with Advanced Approaches: The 4th B Chromosome Conference
(Karger, 2020-04-01)
B chromosomes (Bs) are enigmatic accessory genomic elements extensively characterized in diverse eukaryotes. Since their discovery in the beginning of the 20th century, B chromosomes have been the subject of investigation ...
Chromosomal Mapping of Repetitive DNAs in Characidium (Teleostei, Characiformes): Genomic Organization and Diversification of ZW Sex Chromosomes
(Karger, 2015-01-01)
The speciose neotropical genus Characidium has proven to be a good model for cytogenetic exploration. Representatives of this genus often have a conserved diploid chromosome number; some species exhibit a highly differentiated ...
Investigation of Partamona helleri (Apidae, Meliponini) B chromosome origin. An approach by microdissection and whole chromosome painting
(2013-01-01)
The stingless bee Partamona helleri in southeast Brazil shows the regular chromosome number 2n = 34 and a variable number of up to four minute B1 or B2 chromosomes. Previous cytogenetic analyses have indicated morphological ...
Different responses to doxorubicin-induced chromosome aberrations in Brazilian deer species
(Funpec-editora, 2010-01-01)
The tendency toward chromosome fragility is one of the theories that may explain chromosome variation in brocket deer species (genus Mazama). We tested doxorubicin as an inducer of chromosome aberrations in lymphocytes of ...
Cytogenetic mapping of the W chromosome in the genus Leporinus (Teleostei, Anostomidae) using a highly repetitive DNA sequence
(Wiley-Blackwell, 2012-03-01)
The distribution of the Leporinus elongatus LeSpeI repetitive sequence in other Leporinus species was studied in an attempt to elucidate the evolutionary history of sex chromosomes in this genus using chromosome fluorescence ...
B-chromosomes in two Brazilian populations of Dendropsophus nanus (Anura, Hylidae)
(Sociedade Brasileira de Genética, 2006-01-01)
We report on the presence of B-chromosomes in two populations of Dendropsophus nanus (= Hyla nana Boulenger, 1889) from São Paulo State, Brazil. Such chromosomes were observed in 4 out of 43 specimens (9.3%) and in 9 out ...
Localization of rDNA sites in holocentric chromosomes of three species of triatomines (Heteroptera, Triatominae).
(2005-12-30)
Chromatin organization in the holocentric chromosomes of three triatomines species was cytologically studied by fluorescent in situ hybridization with a 45S rDNA probe of Drosophila melanogaster to localize ribosomal genes. ...
Intraspecific crosses resulting in the first occurrence of eight and nine B chromosomes in Prochilodus lineatus (Characiformes, Prochilodontidae)
(Sociedade Brasileira de Genética, 2011-01-01)
B chromosomes are supernumerary elements present in about 15% of eukaryotic species and are most frequently heterochromatic, behave parasitically, show a transmission rate higher than standard (A) chromosomes, and can ...
Origin and Evolution of B Chromosomes in the Cichlid Fish Astatotilapia latifasciata Based on Integrated Genomic Analyses
(Oxford Univ Press, 2014-08-01)
Approximately 15% of eukaryotes contain supernumerary B chromosomes. When present, B chromosomes frequently represent as much as 5% of the genome. Despite thousands of reports describing the distribution of supernumeraries ...