Cristiano Neves Do Nascimento - Academia.edu (original) (raw)
Graduated in Biological Sciences from the State University of Mato Grosso - UNEMAT - Brazil
less
Related Authors
Universidade Estadual Paulista "Júlio de Mesquita Filho"
Universidade Estadual Paulista "Júlio de Mesquita Filho"
Uploads
Papers by Cristiano Neves Do Nascimento
Animals
B chromosomes are extra-genomic components of cells found in individuals and in populations of so... more B chromosomes are extra-genomic components of cells found in individuals and in populations of some eukaryotic organisms. They have been described since the first observations of chromosomes, but several aspects of their biology remain enigmatic. Despite being present in hundreds of fungi, plants, and animal species, only a small number of B chromosomes have been investigated through high-throughput analyses, revealing the remarkable mechanisms employed by these elements to ensure their maintenance. Populations of the Psalidodon scabripinnis species complex exhibit great B chromosome diversity, making them a useful material for various analyses. In recent years, important aspects of their biology have been revealed. Here, we review these studies presenting a comprehensive view of the B chromosomes in the P. scabripinnis complex and a new hypothesis regarding the role of the B chromosome in the speciation process.
Comparative Cytogenetics, May 5, 2022
The genus Eigenmannia Jordan et Evermann,1896 includes electric fishes endemic to the Neotropical... more The genus Eigenmannia Jordan et Evermann,1896 includes electric fishes endemic to the Neotropical region with extensive karyotype variability and occurrence of different sex chromosome systems, however, cytogenetic studies within this group are restricted to few species. Here, we describe the karyotypes of Eigenmannia limbata (Schreiner et Miranda Ribeiro, 1903) and E. microstoma (Reinhardt, 1852) and the chromosomal locations of 5S and 18S rDNAs (ribosomal RNA genes) and U2 snDNA (small nuclear RNA gene). Among them, 18S rDNA sites were situated in only one chromosomal pair in both species, and co-localized with 5S rDNA in E. microstoma. On the other hand, 5S rDNA and U2 snRNA sites were observed on several chromosomes, with variation in the number of sites between species under study. These two repetitive DNAs were observed co-localized in one chromosomal pair in E. limbata and in four pairs in E. microstoma. Our study shows a new case of association of these two types of repetitive DNA in the genome of Gymnotiformes.
Genetics and Molecular Biology, 2020
Animals
B chromosomes are extra-genomic components of cells found in individuals and in populations of so... more B chromosomes are extra-genomic components of cells found in individuals and in populations of some eukaryotic organisms. They have been described since the first observations of chromosomes, but several aspects of their biology remain enigmatic. Despite being present in hundreds of fungi, plants, and animal species, only a small number of B chromosomes have been investigated through high-throughput analyses, revealing the remarkable mechanisms employed by these elements to ensure their maintenance. Populations of the Psalidodon scabripinnis species complex exhibit great B chromosome diversity, making them a useful material for various analyses. In recent years, important aspects of their biology have been revealed. Here, we review these studies presenting a comprehensive view of the B chromosomes in the P. scabripinnis complex and a new hypothesis regarding the role of the B chromosome in the speciation process.
Comparative Cytogenetics, May 5, 2022
The genus Eigenmannia Jordan et Evermann,1896 includes electric fishes endemic to the Neotropical... more The genus Eigenmannia Jordan et Evermann,1896 includes electric fishes endemic to the Neotropical region with extensive karyotype variability and occurrence of different sex chromosome systems, however, cytogenetic studies within this group are restricted to few species. Here, we describe the karyotypes of Eigenmannia limbata (Schreiner et Miranda Ribeiro, 1903) and E. microstoma (Reinhardt, 1852) and the chromosomal locations of 5S and 18S rDNAs (ribosomal RNA genes) and U2 snDNA (small nuclear RNA gene). Among them, 18S rDNA sites were situated in only one chromosomal pair in both species, and co-localized with 5S rDNA in E. microstoma. On the other hand, 5S rDNA and U2 snRNA sites were observed on several chromosomes, with variation in the number of sites between species under study. These two repetitive DNAs were observed co-localized in one chromosomal pair in E. limbata and in four pairs in E. microstoma. Our study shows a new case of association of these two types of repetitive DNA in the genome of Gymnotiformes.
Genetics and Molecular Biology, 2020