Exophenotypic effects of chromosomal change: The case of Leptysma argentina (orthoptera)

Most of the literature about phenotypic effects of chromosomal change has dealt with its effects on chiasma frequency and/or distribution, whereas whether or not they affect the exophenotype has received less attention and has remained controversial. In the present paper morphometrical variables of...

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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_0018067X_v79_n6_p631_Colombo
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spelling todo:paper_0018067X_v79_n6_p631_Colombo2023-10-03T14:15:26Z Exophenotypic effects of chromosomal change: The case of Leptysma argentina (orthoptera) Colombo, P.C. Centric fusions Chromosome polymorphisms Morphometrical variables Orthoptera Supernumerary segments Leptysma Leptysma argentina Orthoptera Most of the literature about phenotypic effects of chromosomal change has dealt with its effects on chiasma frequency and/or distribution, whereas whether or not they affect the exophenotype has received less attention and has remained controversial. In the present paper morphometrical variables of the species Leptysma argentina were analysed in connection with chromosome polymorphisms for a centric fusion and a supernumerary segment. The centric fusion between pairs 3 and 6 (fusion 3/6) and a supernumerary segment in the smallest pair of the complement (s1) were consistently proved to have effects on chiasma frequency and position; preliminary analyses had shown, however, that fusion 3/6 could be correlated with some effects on body size (Colombo, 1989). In the present paper the analysis of femur, tibia, prothorax and total length as well as prothorax height on larger samples were consistent in showing that both polymorphisms are positively correlated with increasing total length; in the case of the supernumerary segment, however, this effect is not constant over all the populations sampled. An adaptive change in body size may be achieved through selection on: (i) genetic factors that affect this trait; or (ii) chromosome polymorphisms with exophenotypic effects. This latter case would be more effective, because genetic factors are usually polygenic and hence their response to selection would be slow. It is tempting to say that this could be the case for L. argentina, because in grasshoppers increased body size can be related to tolerance to cold or dry environments. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_0018067X_v79_n6_p631_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 Centric fusions
Chromosome polymorphisms
Morphometrical variables
Orthoptera
Supernumerary segments
Leptysma
Leptysma argentina
Orthoptera
spellingShingle Centric fusions
Chromosome polymorphisms
Morphometrical variables
Orthoptera
Supernumerary segments
Leptysma
Leptysma argentina
Orthoptera
Colombo, P.C.
Exophenotypic effects of chromosomal change: The case of Leptysma argentina (orthoptera)
topic_facet Centric fusions
Chromosome polymorphisms
Morphometrical variables
Orthoptera
Supernumerary segments
Leptysma
Leptysma argentina
Orthoptera
description Most of the literature about phenotypic effects of chromosomal change has dealt with its effects on chiasma frequency and/or distribution, whereas whether or not they affect the exophenotype has received less attention and has remained controversial. In the present paper morphometrical variables of the species Leptysma argentina were analysed in connection with chromosome polymorphisms for a centric fusion and a supernumerary segment. The centric fusion between pairs 3 and 6 (fusion 3/6) and a supernumerary segment in the smallest pair of the complement (s1) were consistently proved to have effects on chiasma frequency and position; preliminary analyses had shown, however, that fusion 3/6 could be correlated with some effects on body size (Colombo, 1989). In the present paper the analysis of femur, tibia, prothorax and total length as well as prothorax height on larger samples were consistent in showing that both polymorphisms are positively correlated with increasing total length; in the case of the supernumerary segment, however, this effect is not constant over all the populations sampled. An adaptive change in body size may be achieved through selection on: (i) genetic factors that affect this trait; or (ii) chromosome polymorphisms with exophenotypic effects. This latter case would be more effective, because genetic factors are usually polygenic and hence their response to selection would be slow. It is tempting to say that this could be the case for L. argentina, because in grasshoppers increased body size can be related to tolerance to cold or dry environments.
format JOUR
author Colombo, P.C.
author_facet Colombo, P.C.
author_sort Colombo, P.C.
title Exophenotypic effects of chromosomal change: The case of Leptysma argentina (orthoptera)
title_short Exophenotypic effects of chromosomal change: The case of Leptysma argentina (orthoptera)
title_full Exophenotypic effects of chromosomal change: The case of Leptysma argentina (orthoptera)
title_fullStr Exophenotypic effects of chromosomal change: The case of Leptysma argentina (orthoptera)
title_full_unstemmed Exophenotypic effects of chromosomal change: The case of Leptysma argentina (orthoptera)
title_sort exophenotypic effects of chromosomal change: the case of leptysma argentina (orthoptera)
url http://hdl.handle.net/20.500.12110/paper_0018067X_v79_n6_p631_Colombo
work_keys_str_mv AT colombopc exophenotypiceffectsofchromosomalchangethecaseofleptysmaargentinaorthoptera
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