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Mostrando ítems 31-40 de 1829
Cytogenetic analysis of A-, B-chromosomes and ZZ/ZW sex chromosomes of Characidium gomesi (Teleostei, Characiformes, Crenuchidae)
(2004-06-01)
Different cytogenetic techniques were used to analyze the chromosomes of Characidium gomesi with the main objective of comparing the base composition of ZZ/ZW sex-chromosomes, B-chromosomes and the heterochromatin of ...
Cytogenetic analysis of A-, B-chromosomes and ZZ/ZW sex chromosomes of Characidium gomesi (Teleostei, Characiformes, Crenuchidae)
(2004-06-01)
Different cytogenetic techniques were used to analyze the chromosomes of Characidium gomesi with the main objective of comparing the base composition of ZZ/ZW sex-chromosomes, B-chromosomes and the heterochromatin of ...
More sex chromosomes than autosomes in the Amazonian frog Leptodactylus pentadactylus
(2018-06-01)
Heteromorphic sex chromosomes are common in eukaryotes and largely ubiquitous in birds and mammals. The largest number of multiple sex chromosomes in vertebrates known today is found in the monotreme platypus (Ornithorhynchus ...
Kinetic activity of the sex chromosomes of Mormidea paupercula (Pentatomidae, Heteroptera)
(Czech Academy of Sciences, 2010-07)
InMormidea paupercula (n = 6 + XY in males), the presence of a CMA3-bright band in the telomeric regions on both sexchromosomes allowed the analysis of the kinetic activity of the sex univalents and XY pseudobivalent at ...
Heteropicnotic chromatin and nucleolar activity in meiosis and spermiogenesis of Limnogonus aduncus (Heteroptera, Gerridae): a stained nucleolar organizing region that can serve as a model for studying chromosome behavior.
(2008-12-01)
Males of Limnogonus aduncus were found to have the sex chromosome system X0 and chromosome number 2n = 23 (22A + X0). Testis cells were stained with lacto-acetic orcein and silver nitrate so that changes in the morphology ...
Heteropicnotic chromatin and nucleolar activity in meiosis and spermiogenesis of Limnogonus aduncus (Heteroptera, Gerridae): a stained nucleolar organizing region that can serve as a model for studying chromosome behavior.
(2008-12-01)
Males of Limnogonus aduncus were found to have the sex chromosome system X0 and chromosome number 2n = 23 (22A + X0). Testis cells were stained with lacto-acetic orcein and silver nitrate so that changes in the morphology ...
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 ...
MARSUPIAL SEX CHROMOSOME BEHAVIOUR DURING MALE MEIOSIS
(SPRINGER, 2010)
The absence of homology between sex chromosomes in marsupials strongly influences their behaviour during male meiosis. The highly differentiated X and Y chromosomes perform a precise and specific meiotic program that ...
XX : XY sex chromosome system with X heterochromatinization: an early stage of sex chromosome differentiation in the Neotropic electric eel Eigenmannia virescens
(Karger, 2001-01-01)
An early stage of sex chromosome differentiation is reported to occur in the electric eel Eigenmannia virescens (Pisces, Sternopygidae) from populations of two tributaries of the Parana river system (Brazil). Cytogenetic ...
The program of sex chromosome pairing in meiosis is highly conserved across marsupial species: Implications for sex chromosome evolution
(GENETICS, 2005-06)
Marsupials present a series of genetic and chromosomal features that are highly conserved in very distant species. One of these features is the absence of a homologous region between X and Y chromosomes. According to this ...