Metaphase I orientation of Robertsonian trivalents in the water-hyacinth grasshopper, Cornops aquaticum (Acrididae, Orthoptera)

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...

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Autor principal: Colombo, P.C.
Formato: JOUR
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_14154757_v32_n1_p91_Colombo
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spelling todo:paper_14154757_v32_n1_p91_Colombo2023-10-03T16:13:09Z Metaphase I orientation of Robertsonian trivalents in the water-hyacinth grasshopper, Cornops aquaticum (Acrididae, Orthoptera) Colombo, P.C. Cornops aquaticum Metaphase I orientation Robertsonian rearrangements Trivalents anaphase animal tissue article chromosome rearrangement Cornops aquaticum correlation analysis cytogenetics enzyme polymorphism heterozygosity male metaphase molecular evolution nonhuman Orthoptera Robertsonian rearrangement spermatid Acrididae Cornops Cornops aquaticum Eichhornia crassipes Orthoptera Robertsonia Schistocerca americana 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 aquaticumis 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. Copyright © 2009, Sociedade Brasileira de Genética. Fil:Colombo, P.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_14154757_v32_n1_p91_Colombo
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Cornops aquaticum
Metaphase I orientation
Robertsonian rearrangements
Trivalents
anaphase
animal tissue
article
chromosome rearrangement
Cornops aquaticum
correlation analysis
cytogenetics
enzyme polymorphism
heterozygosity
male
metaphase
molecular evolution
nonhuman
Orthoptera
Robertsonian rearrangement
spermatid
Acrididae
Cornops
Cornops aquaticum
Eichhornia crassipes
Orthoptera
Robertsonia
Schistocerca americana
spellingShingle Cornops aquaticum
Metaphase I orientation
Robertsonian rearrangements
Trivalents
anaphase
animal tissue
article
chromosome rearrangement
Cornops aquaticum
correlation analysis
cytogenetics
enzyme polymorphism
heterozygosity
male
metaphase
molecular evolution
nonhuman
Orthoptera
Robertsonian rearrangement
spermatid
Acrididae
Cornops
Cornops aquaticum
Eichhornia crassipes
Orthoptera
Robertsonia
Schistocerca americana
Colombo, P.C.
Metaphase I orientation of Robertsonian trivalents in the water-hyacinth grasshopper, Cornops aquaticum (Acrididae, Orthoptera)
topic_facet Cornops aquaticum
Metaphase I orientation
Robertsonian rearrangements
Trivalents
anaphase
animal tissue
article
chromosome rearrangement
Cornops aquaticum
correlation analysis
cytogenetics
enzyme polymorphism
heterozygosity
male
metaphase
molecular evolution
nonhuman
Orthoptera
Robertsonian rearrangement
spermatid
Acrididae
Cornops
Cornops aquaticum
Eichhornia crassipes
Orthoptera
Robertsonia
Schistocerca americana
description 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 aquaticumis 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. Copyright © 2009, Sociedade Brasileira de Genética.
format JOUR
author Colombo, P.C.
author_facet Colombo, P.C.
author_sort Colombo, P.C.
title Metaphase I orientation of Robertsonian trivalents in the water-hyacinth grasshopper, Cornops aquaticum (Acrididae, Orthoptera)
title_short Metaphase I orientation of Robertsonian trivalents in the water-hyacinth grasshopper, Cornops aquaticum (Acrididae, Orthoptera)
title_full Metaphase I orientation of Robertsonian trivalents in the water-hyacinth grasshopper, Cornops aquaticum (Acrididae, Orthoptera)
title_fullStr Metaphase I orientation of Robertsonian trivalents in the water-hyacinth grasshopper, Cornops aquaticum (Acrididae, Orthoptera)
title_full_unstemmed Metaphase I orientation of Robertsonian trivalents in the water-hyacinth grasshopper, Cornops aquaticum (Acrididae, Orthoptera)
title_sort metaphase i orientation of robertsonian trivalents in the water-hyacinth grasshopper, cornops aquaticum (acrididae, orthoptera)
url http://hdl.handle.net/20.500.12110/paper_14154757_v32_n1_p91_Colombo
work_keys_str_mv AT colombopc metaphaseiorientationofrobertsoniantrivalentsinthewaterhyacinthgrasshoppercornopsaquaticumacrididaeorthoptera
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