Cytogeography of three parallel Robertsonian polymorphisms in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)

C. aquaticum (Acrididae: Leptysminae) inhabits water-hyacinths in the Neotropical region. The blue-flowered water-hyacinth, Eichhornia crassipes, has been introduced elsewhere without its natural enemies and has become a weed; recently C. aquaticum was considered as a possible biological control age...

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Detalles Bibliográficos
Autor principal: Colombo, P.C.
Formato: JOUR
Materias:
Acrididae
Chromosomal cline
Cornops aquaticum
Recombination
Robertsonian translocations
chromosome
grasshopper
polymorphism
recombination
sex determination
Parana River
South America
Eichhornia
Eichhornia crassipes
Leptysminae
Orthoptera
Robertsonia
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_12105759_v105_n1_p59_Colombo
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_12105759_v105_n1_p59_Colombo
record_format dspace
spelling todo:paper_12105759_v105_n1_p59_Colombo2023-10-03T16:08:59Z Cytogeography of three parallel Robertsonian polymorphisms in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae) Colombo, P.C. Acrididae Chromosomal cline Cornops aquaticum Recombination Robertsonian translocations chromosome grasshopper polymorphism recombination sex determination Parana River South America Acrididae Cornops aquaticum Eichhornia Eichhornia crassipes Leptysminae Orthoptera Robertsonia C. aquaticum (Acrididae: Leptysminae) inhabits water-hyacinths in the Neotropical region. The blue-flowered water-hyacinth, Eichhornia crassipes, has been introduced elsewhere without its natural enemies and has become a weed; recently C. aquaticum was considered as a possible biological control agent. In this work, six populations were sampled and cytologically studied. C. aquaticum has 2n - 23 chromosomes in males and 24 in females, with an XO/XX sex determination system. All chromosomes are acro-telocentric and the basic karyotype includes three Robertsonian (Rb) translocations between pairs 1/6, 2/5, and 3/4. These polymorphisms are restricted to the lower course of the Paraná river, between Rosario and Buenos Aires. Fusion frequencies increase southwards, thus showing a geographical cline. The polymorphisms mostly accord with Hardy-Weinberg and gametic phase equilibria. The rearrangements cause a drastic chiasma repatterning in the fusion bivalents (or trivalents) which reduces the proximal Asma frequency. Recombination is also reduced due to the loss of independent segregation. A recombination index that takes into account both these factors correlates negatively with the her of pairs of chromosomes affected by fusions among populations, which does not accord with the "central-marginal" pattern. 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_12105759_v105_n1_p59_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 Acrididae
Chromosomal cline
Cornops aquaticum
Recombination
Robertsonian translocations
chromosome
grasshopper
polymorphism
recombination
sex determination
Parana River
South America
Acrididae
Cornops aquaticum
Eichhornia
Eichhornia crassipes
Leptysminae
Orthoptera
Robertsonia
spellingShingle Acrididae
Chromosomal cline
Cornops aquaticum
Recombination
Robertsonian translocations
chromosome
grasshopper
polymorphism
recombination
sex determination
Parana River
South America
Acrididae
Cornops aquaticum
Eichhornia
Eichhornia crassipes
Leptysminae
Orthoptera
Robertsonia
Colombo, P.C.
Cytogeography of three parallel Robertsonian polymorphisms in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
topic_facet Acrididae
Chromosomal cline
Cornops aquaticum
Recombination
Robertsonian translocations
chromosome
grasshopper
polymorphism
recombination
sex determination
Parana River
South America
Acrididae
Cornops aquaticum
Eichhornia
Eichhornia crassipes
Leptysminae
Orthoptera
Robertsonia
description C. aquaticum (Acrididae: Leptysminae) inhabits water-hyacinths in the Neotropical region. The blue-flowered water-hyacinth, Eichhornia crassipes, has been introduced elsewhere without its natural enemies and has become a weed; recently C. aquaticum was considered as a possible biological control agent. In this work, six populations were sampled and cytologically studied. C. aquaticum has 2n - 23 chromosomes in males and 24 in females, with an XO/XX sex determination system. All chromosomes are acro-telocentric and the basic karyotype includes three Robertsonian (Rb) translocations between pairs 1/6, 2/5, and 3/4. These polymorphisms are restricted to the lower course of the Paraná river, between Rosario and Buenos Aires. Fusion frequencies increase southwards, thus showing a geographical cline. The polymorphisms mostly accord with Hardy-Weinberg and gametic phase equilibria. The rearrangements cause a drastic chiasma repatterning in the fusion bivalents (or trivalents) which reduces the proximal Asma frequency. Recombination is also reduced due to the loss of independent segregation. A recombination index that takes into account both these factors correlates negatively with the her of pairs of chromosomes affected by fusions among populations, which does not accord with the "central-marginal" pattern.
format JOUR
author Colombo, P.C.
author_facet Colombo, P.C.
author_sort Colombo, P.C.
title Cytogeography of three parallel Robertsonian polymorphisms in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
title_short Cytogeography of three parallel Robertsonian polymorphisms in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
title_full Cytogeography of three parallel Robertsonian polymorphisms in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
title_fullStr Cytogeography of three parallel Robertsonian polymorphisms in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
title_full_unstemmed Cytogeography of three parallel Robertsonian polymorphisms in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
title_sort cytogeography of three parallel robertsonian polymorphisms in the water-hyacinth grasshopper, cornops aquaticum (orthoptera: acrididae)
url http://hdl.handle.net/20.500.12110/paper_12105759_v105_n1_p59_Colombo
work_keys_str_mv AT colombopc cytogeographyofthreeparallelrobertsonianpolymorphismsinthewaterhyacinthgrasshoppercornopsaquaticumorthopteraacrididae
_version_ 1782026901178548224

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