Effects of polymorphic Robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)

The New World grasshopper Cornops aquaticum (Leptysminae: Acrididae) shows a geographical pattern for three Robertsonian polymorphisms in its southernmost area of distribution in Argentina and Uruguay: The frequency and distribution of chiasmata were analysed in five Argentinian populations. This st...

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Autor principal:	Colombo, P.C.
Formato:	JOUR
Materias:	Acrididae Chiasma distribution Chiasma interference Cornops aquaticum Recombination Robertsonian polymorphisms frequency-magnitude distribution genetic analysis genetic structure genetic variation geographical distribution grasshopper heterozygosity karyotype polymorphism recombination Argentina Paraguay South America Eichhornia crassipes Leptysminae Orthoptera Robertsonia
Acceso en línea:	http://hdl.handle.net/20.500.12110/paper_12105759_v104_n4_p653_Colombo
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	todo:paper_12105759_v104_n4_p653_Colombo
record_format	dspace
spelling	todo:paper_12105759_v104_n4_p653_Colombo2023-10-03T16:08:59Z Effects of polymorphic Robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae) Colombo, P.C. Acrididae Chiasma distribution Chiasma interference Cornops aquaticum Recombination Robertsonian polymorphisms frequency-magnitude distribution genetic analysis genetic structure genetic variation geographical distribution grasshopper heterozygosity karyotype polymorphism recombination Argentina Paraguay South America Acrididae Cornops aquaticum Eichhornia crassipes Leptysminae Orthoptera Robertsonia The New World grasshopper Cornops aquaticum (Leptysminae: Acrididae) shows a geographical pattern for three Robertsonian polymorphisms in its southernmost area of distribution in Argentina and Uruguay: The frequency and distribution of chiasmata were analysed in five Argentinian populations. This study reveals a strong redistribution of chiasmata in fusion carriers, with a reduction in proximal and increase of distal chiasma frequency in fusion bivalents and trivalents, when all three karyotypes were compared. However, when only fusion bivalents and trivalents were compared, chiasma frequency was significantly higher in the former than in the latter. This higher chiasma frequency in fusion bivalents is due to an increase in proximal chiasma frequency. It is argued that the reduction in proximal chiasma frequency (relative to unfused bivalents) in fusion bivalents may be due to interference across the centromere. Proximal chiasma reduction in trivalents may be attributed either to a physical effect of structural heterozygosity or to an adaptation to the polymorphic condition. Therefore the differences in the-distribution of chiasmata in trivalents and Robertsonian bivalents have different causes. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_12105759_v104_n4_p653_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 Chiasma distribution Chiasma interference Cornops aquaticum Recombination Robertsonian polymorphisms frequency-magnitude distribution genetic analysis genetic structure genetic variation geographical distribution grasshopper heterozygosity karyotype polymorphism recombination Argentina Paraguay South America Acrididae Cornops aquaticum Eichhornia crassipes Leptysminae Orthoptera Robertsonia
spellingShingle	Acrididae Chiasma distribution Chiasma interference Cornops aquaticum Recombination Robertsonian polymorphisms frequency-magnitude distribution genetic analysis genetic structure genetic variation geographical distribution grasshopper heterozygosity karyotype polymorphism recombination Argentina Paraguay South America Acrididae Cornops aquaticum Eichhornia crassipes Leptysminae Orthoptera Robertsonia Colombo, P.C. Effects of polymorphic Robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
topic_facet	Acrididae Chiasma distribution Chiasma interference Cornops aquaticum Recombination Robertsonian polymorphisms frequency-magnitude distribution genetic analysis genetic structure genetic variation geographical distribution grasshopper heterozygosity karyotype polymorphism recombination Argentina Paraguay South America Acrididae Cornops aquaticum Eichhornia crassipes Leptysminae Orthoptera Robertsonia
description	The New World grasshopper Cornops aquaticum (Leptysminae: Acrididae) shows a geographical pattern for three Robertsonian polymorphisms in its southernmost area of distribution in Argentina and Uruguay: The frequency and distribution of chiasmata were analysed in five Argentinian populations. This study reveals a strong redistribution of chiasmata in fusion carriers, with a reduction in proximal and increase of distal chiasma frequency in fusion bivalents and trivalents, when all three karyotypes were compared. However, when only fusion bivalents and trivalents were compared, chiasma frequency was significantly higher in the former than in the latter. This higher chiasma frequency in fusion bivalents is due to an increase in proximal chiasma frequency. It is argued that the reduction in proximal chiasma frequency (relative to unfused bivalents) in fusion bivalents may be due to interference across the centromere. Proximal chiasma reduction in trivalents may be attributed either to a physical effect of structural heterozygosity or to an adaptation to the polymorphic condition. Therefore the differences in the-distribution of chiasmata in trivalents and Robertsonian bivalents have different causes.
format	JOUR
author	Colombo, P.C.
author_facet	Colombo, P.C.
author_sort	Colombo, P.C.
title	Effects of polymorphic Robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
title_short	Effects of polymorphic Robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
title_full	Effects of polymorphic Robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
title_fullStr	Effects of polymorphic Robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
title_full_unstemmed	Effects of polymorphic Robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)
title_sort	effects of polymorphic robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, cornops aquaticum (orthoptera: acrididae)
url	http://hdl.handle.net/20.500.12110/paper_12105759_v104_n4_p653_Colombo
work_keys_str_mv	AT colombopc effectsofpolymorphicrobertsonianrearrangementsonthefrequencyanddistributionofchiasmatainthewaterhyacinthgrasshoppercornopsaquaticumorthopteraacrididae
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Effects of polymorphic Robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)

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