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Artigo
The distribution of 45s rDNA sites in bird chromosomes suggests multiple evolutionary histories
The distribution of 45S rDNA cluster in avian karyotypes varies in different aspects, such as position, number of bearer chromosomes, and bearers being macro- or microchromosomes. The present study investigated the patterns of variation in the 45S rDNA-bearer chromosomes of birds in order to under...
Autor principal: | Degrandi, Tiago Marafiga |
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Outros Autores: | Gunski, Ricardo Jos?, Garnero, Anal?a del Valle, Oliveira, Edivaldo Herculano Correa de, Krestschmer, Rafael, Souza, Marcelo Santos de, Barcellos, Suziane Alves, Hass, Iris |
Grau: | Artigo |
Idioma: | eng |
Publicado em: |
Sociedade Brasileira de Gen?tica
2020
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Assuntos: | |
Acesso em linha: |
http://patua.iec.gov.br//handle/iec/4089 |
Resumo: |
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The distribution of 45S rDNA cluster in avian karyotypes varies in different aspects, such as position, number of
bearer chromosomes, and bearers being macro- or microchromosomes. The present study investigated the patterns
of variation in the 45S rDNA-bearer chromosomes of birds in order to understand the evolutionary dynamics of the
cluster configuration and its contribution to the evolution of bird karyotypes. A total of 73 bird species were analyzed,
including both published data and species for which rDNA-FISH was conducted for the first time. In most birds, the
45S rDNA clusters were located in a single pair of microchromosomes. Hence, the location of 45S rDNA in
macrochromosomes, observed only in Neognathae species, seems to be a derived state, probably the result of chromosomal fusion between microchromosomes and distinct macrochromosomes. Additionally, the 45S rDNA was observed in multiple microchromosomes in different branches of the bird phylogeny, suggesting recurrence of
dispersion processeses, such as duplications and translocations. Overall, this study indicated that the redistribution
of the 45S rDNA sites in bird chromosomes followed different evolutionary trajectories with respect to each lineage of
the class Aves. |