Autosomal univalents as a common meiotic feature in Jadera haematoloma and Jadera sanguinolenta (Heteroptera: Rhopalidae: Serinethinae)

So far, available cytogenetic data on 24 species of Rhopalidae reveal a male diploid chromosome number of 13, with a pair of m chromosomes and an XO/XX (male/female) sex chromosome determining system. As a rule Heteroptera have holokinetic chromosomes and a pre-reductional type of meiosis: the autos...

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Detalles Bibliográficos
Autores principales: Bressa, María José, Papeschi, Alba G., Mola, L., Larramendy, Marcelo Luis
Formato: Articulo
Lenguaje:Inglés
Publicado: 2001
Materias:
Ciencias Naturales
Jadera haematoloma
Jadera sanguinolenta
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84889
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-84889
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Naturales
Jadera haematoloma
Jadera sanguinolenta
spellingShingle Ciencias Naturales
Jadera haematoloma
Jadera sanguinolenta
Bressa, María José
Papeschi, Alba G.
Mola, L.
Larramendy, Marcelo Luis
Autosomal univalents as a common meiotic feature in Jadera haematoloma and Jadera sanguinolenta (Heteroptera: Rhopalidae: Serinethinae)
topic_facet Ciencias Naturales
Jadera haematoloma
Jadera sanguinolenta
description So far, available cytogenetic data on 24 species of Rhopalidae reveal a male diploid chromosome number of 13, with a pair of m chromosomes and an XO/XX (male/female) sex chromosome determining system. As a rule Heteroptera have holokinetic chromosomes and a pre-reductional type of meiosis: the autosomal bivalents and the m pseudobivalent segregate reductionally at first meiotic division, while the X chromosome segregates equationally. In the present study, the meiotic chromosome behaviour was analyzed in males from different Argentinean populations of <i>Jadera haematoloma</i> and <i>J. sanguinolenta</i>. Our results corroborate the diploid chromosome number and general patterns of male meiosis previously reported by other authors in samples from Brazil and Texas (USA). Among bivalents, one is remarkably larger and may present one or two terminal chiasmata. Comparison of mean chiasma frequency between <i>Jadera haematoloma</i> (5.63) and <i>J. sanguinolenta</i> (5.14) revealed that differences are significant. In most individuals of both species the largest pair appears as univalents in a variable number of cells and shows a regular meiotic segregation. Autosomal univalents orientate axially at metaphase I (with their long axis parallel to the spindle axis) and segregate equationally at anaphase I. At metaphase II they associate end-to-end forming a pseudobivalent that segregates reductionally at anaphase II. An hypothesis is suggested to explain the appearance of the largest pair, either as a ring/rod bivalent or as univalents within the same individual, although an asynaptic or desynaptic origin of the univalents cannot be ascertained. The highly regular meiotic behaviour of this autosomal pair could ensure a high fertility of the individuals, and could be considered a selectively neutral condition or, at least, not detrimental.
format Articulo
Articulo
author Bressa, María José
Papeschi, Alba G.
Mola, L.
Larramendy, Marcelo Luis
author_facet Bressa, María José
Papeschi, Alba G.
Mola, L.
Larramendy, Marcelo Luis
author_sort Bressa, María José
title Autosomal univalents as a common meiotic feature in Jadera haematoloma and Jadera sanguinolenta (Heteroptera: Rhopalidae: Serinethinae)
title_short Autosomal univalents as a common meiotic feature in Jadera haematoloma and Jadera sanguinolenta (Heteroptera: Rhopalidae: Serinethinae)
title_full Autosomal univalents as a common meiotic feature in Jadera haematoloma and Jadera sanguinolenta (Heteroptera: Rhopalidae: Serinethinae)
title_fullStr Autosomal univalents as a common meiotic feature in Jadera haematoloma and Jadera sanguinolenta (Heteroptera: Rhopalidae: Serinethinae)
title_full_unstemmed Autosomal univalents as a common meiotic feature in Jadera haematoloma and Jadera sanguinolenta (Heteroptera: Rhopalidae: Serinethinae)
title_sort autosomal univalents as a common meiotic feature in jadera haematoloma and jadera sanguinolenta (heteroptera: rhopalidae: serinethinae)
publishDate 2001
url http://sedici.unlp.edu.ar/handle/10915/84889
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