Data/hora: 02/06/2024 00:34:08

Provedor de dados: | 74
País: | Brazil
Título: | Metaphase I orientation of Robertsonian trivalents in the water-hyacinth grasshopper, Cornops aquaticum (Acrididae, Orthoptera)
Autores: | Colombo,Pablo César.
Data: | 2009-01-01
Ano: | 2009
Palavras-chave: | Cornops aquaticum; Robertsonian rearrangements; Trivalents; Metaphase I orientation.
Resumo: | Trivalents resulting from polymorphic Robertsonian rearrangements must have a regular orientation in metaphase I if the polymorphisms are to be maintained. It has been argued that redistribution of proximal and interstitial chiasmata to more distal positions is necessary for a convergent orientation, the only one that produces viable gametes. Cornops aquaticum is a South-American grasshopper that lives and feeds on water-hyacinths, and has three polymorphic Robertsonian rearrangements in its southernmost distribution area in Central Argentina and Uruguay. The orientation of trivalents in metaphase I, the formation of abnormal spermatids and the frequency and position of chiasmata in the trivalents, was analysed in a polymorphic population of C. aquaticus. In this study we observed a correlation between the number of trivalents with the frequency of abnormal spermatids; additionally, the number of chiasmata, especially proximal and interstitial ones, was strongly correlated with the frequency of the linear orientation. Therefore we confirmed our previous assumption, based on other evidence, that the chiasmata redistribution in fusion carriers is essential to the maintenance of the polymorphisms.
Tipo: | Info:eu-repo/semantics/other
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000100013
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572009005000019
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.32 n.1 2009
Fonte: | info:eu-repo/semantics/openAccess