Orientation and segregation of Robertsonian trivalents in Dichroplus pratensis (Acrididae).

Pairing behavior, metaphase I orientation, and anaphase I segregation of centric fusion trivalents were studied in 26 single, 15 double, and 2 triple male fusion heterozygotes of the polymorphic South American melanopline grasshopper Dichroplus pratensis. They represent the seven different fusions a...

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Autores principales:	Bidau, Claudio Juan, Mirol, Patricia
Publicado:	1988
Materias:	anaphase animal article gene translocation genetic polymorphism genetics grasshopper heterozygote homozygote male metaphase Anaphase Animals Grasshoppers Heterozygote Homozygote Male Metaphase Polymorphism, Genetic Translocation, Genetic
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08312796_v30_n6_p947_Bidau http://hdl.handle.net/20.500.12110/paper_08312796_v30_n6_p947_Bidau
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_08312796_v30_n6_p947_Bidau
record_format	dspace
spelling	paper:paper_08312796_v30_n6_p947_Bidau2023-06-08T15:46:14Z Orientation and segregation of Robertsonian trivalents in Dichroplus pratensis (Acrididae). Bidau, Claudio Juan Mirol, Patricia anaphase animal article gene translocation genetic polymorphism genetics grasshopper heterozygote homozygote male metaphase Anaphase Animals Grasshoppers Heterozygote Homozygote Male Metaphase Polymorphism, Genetic Translocation, Genetic Pairing behavior, metaphase I orientation, and anaphase I segregation of centric fusion trivalents were studied in 26 single, 15 double, and 2 triple male fusion heterozygotes of the polymorphic South American melanopline grasshopper Dichroplus pratensis. They represent the seven different fusions and their combinations already described in different populations of the species. Our analysis showed the following: (1) pairing behavior is very regular in all trivalents; (2) frequencies of linear orientation was very low irrespective of the trivalent involved; (3) reorientation seems to occur frequently since frequencies of abnormal segregation and aneuploid second division cells were invariably lower than those of nonconvergent orientation; (4) aneuploidy and abnormal sperm production increases with increasing number of fusions; (5) chiasma frequency and localisation is relevant to trivalent orientation since trivalents with nonconvergent orientations showed proximal and interstitial chiasmata more frequently than convergently oriented ones. The results are in agreement with the hypothesis that these polymorphisms are old and stable, and confirm that for the maintenance of a balanced polymorphism, if this polymorphism is adaptive because of its consequences on recombination, position effects, etc., changes tending to stabilise trivalent orientation and segregation are central. Fil:Bidau, C.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Mirol, P.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1988 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08312796_v30_n6_p947_Bidau http://hdl.handle.net/20.500.12110/paper_08312796_v30_n6_p947_Bidau
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	anaphase animal article gene translocation genetic polymorphism genetics grasshopper heterozygote homozygote male metaphase Anaphase Animals Grasshoppers Heterozygote Homozygote Male Metaphase Polymorphism, Genetic Translocation, Genetic
spellingShingle	anaphase animal article gene translocation genetic polymorphism genetics grasshopper heterozygote homozygote male metaphase Anaphase Animals Grasshoppers Heterozygote Homozygote Male Metaphase Polymorphism, Genetic Translocation, Genetic Bidau, Claudio Juan Mirol, Patricia Orientation and segregation of Robertsonian trivalents in Dichroplus pratensis (Acrididae).
topic_facet	anaphase animal article gene translocation genetic polymorphism genetics grasshopper heterozygote homozygote male metaphase Anaphase Animals Grasshoppers Heterozygote Homozygote Male Metaphase Polymorphism, Genetic Translocation, Genetic
description	Pairing behavior, metaphase I orientation, and anaphase I segregation of centric fusion trivalents were studied in 26 single, 15 double, and 2 triple male fusion heterozygotes of the polymorphic South American melanopline grasshopper Dichroplus pratensis. They represent the seven different fusions and their combinations already described in different populations of the species. Our analysis showed the following: (1) pairing behavior is very regular in all trivalents; (2) frequencies of linear orientation was very low irrespective of the trivalent involved; (3) reorientation seems to occur frequently since frequencies of abnormal segregation and aneuploid second division cells were invariably lower than those of nonconvergent orientation; (4) aneuploidy and abnormal sperm production increases with increasing number of fusions; (5) chiasma frequency and localisation is relevant to trivalent orientation since trivalents with nonconvergent orientations showed proximal and interstitial chiasmata more frequently than convergently oriented ones. The results are in agreement with the hypothesis that these polymorphisms are old and stable, and confirm that for the maintenance of a balanced polymorphism, if this polymorphism is adaptive because of its consequences on recombination, position effects, etc., changes tending to stabilise trivalent orientation and segregation are central.
author	Bidau, Claudio Juan Mirol, Patricia
author_facet	Bidau, Claudio Juan Mirol, Patricia
author_sort	Bidau, Claudio Juan
title	Orientation and segregation of Robertsonian trivalents in Dichroplus pratensis (Acrididae).
title_short	Orientation and segregation of Robertsonian trivalents in Dichroplus pratensis (Acrididae).
title_full	Orientation and segregation of Robertsonian trivalents in Dichroplus pratensis (Acrididae).
title_fullStr	Orientation and segregation of Robertsonian trivalents in Dichroplus pratensis (Acrididae).
title_full_unstemmed	Orientation and segregation of Robertsonian trivalents in Dichroplus pratensis (Acrididae).
title_sort	orientation and segregation of robertsonian trivalents in dichroplus pratensis (acrididae).
publishDate	1988
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08312796_v30_n6_p947_Bidau http://hdl.handle.net/20.500.12110/paper_08312796_v30_n6_p947_Bidau
work_keys_str_mv	AT bidauclaudiojuan orientationandsegregationofrobertsoniantrivalentsindichropluspratensisacrididae AT mirolpatricia orientationandsegregationofrobertsoniantrivalentsindichropluspratensisacrididae
_version_	1768542945332428800

Orientation and segregation of Robertsonian trivalents in Dichroplus pratensis (Acrididae).

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