High chromosome variability and the presence of multivalent associations in buthid scorpions


Autoria(s): Mattos, Viviane Fagundes; Cella, Doralice Maria; Carvalho, Leonardo Sousa; Candido, Denise Maria; Schneider, Marielle Cristina
Contribuinte(s)

Universidade Estadual Paulista (UNESP)

Data(s)

27/05/2014

27/05/2014

01/04/2013

Resumo

In this study, we investigated the mitotic and meiotic chromosomes of 11 Buthidae scorpion species, belonging to three genera (Ananteris, Rhopalurus and Tityus), to obtain detailed knowledge regarding the mechanisms underlying the intraspecific and/or interspecific diversity of chromosome number and the origin of the complex chromosome associations observed during meiosis. The chromosomes of all species did not exhibit a localised centromere region and presented synaptic and achiasmatic behaviour during meiosis I. Spermatogonial and/or oogonial metaphase cells of these buthids showed diploid numbers range from 2n = 6 to 2n = 28. In most species, multivalent chromosome associations were observed in pachytene and postpachytene nuclei. Moreover, intraspecific variability associated with the presence or absence of chromosome chains and the number of chromosomes in the complex meiotic configurations was observed in some species of these three genera. Silver-impregnated cells revealed that the number and location of nucleolar organiser regions (NORs) remained unchanged despite extensive chromosome variation; notably, two NORs located on the terminal or subterminal chromosome regions were commonly observed for all species. C-banded and fluorochrome-stained cells showed that species with conspicuous blocks of heterochromatin exhibited the lowest rate of chromosomal rearrangement. Based on the investigation of mitotic and meiotic cells, we determined that the intraspecific variability occurred as a consequence of fission/fusion-type chromosomal rearrangements in Ananteris and Tityus species and reciprocal translocation in Rhopalurus species. Furthermore, we verified that individuals presenting the same diploid number differ in structural chromosome organisation, giving rise to intraspecific differences of chromosome association in meiotic cells (bivalent-like elements or chromosome chains). © 2013 Springer Science+Business Media Dordrecht.

Formato

121-136

Identificador

http://dx.doi.org/10.1007/s10577-013-9342-3

Chromosome Research, v. 21, n. 2, p. 121-136, 2013.

0967-3849

1573-6849

http://hdl.handle.net/11449/74903

10.1007/s10577-013-9342-3

WOS:000317688800003

2-s2.0-84880572855

Idioma(s)

eng

Relação

Chromosome Research

Direitos

closedAccess

Palavras-Chave #chromosome rearrangements #evolution #heterozygosity #holocentric #meiosis #nucleolar organiser region #Ananteris #animal cell #cell nucleus #centromere #chromosome #chromosome NOR #chromosome number #controlled study #diploidy #female #genetic variability #heterochromatin #male #metaphase #nonhuman #pachytene #postpachytene #priority journal #reciprocal chromosome translocation #Rhopalurus #scorpion #species diversity #Tityus #Buthida #Buthidae #Scorpiones
Tipo

info:eu-repo/semantics/article