First record on the cytotaxonomy of cicindelids (Insecta, Coleoptera) from an afrotropical region

Abstract

-Karyological investigations were carried out on five species of tiger beetles from the Afrotropical Region belonging to the tribes Megacephalini and Cicindelini. The species have distinct karyotypes either in the number of autosomes and heterosomes or in size and shape of the chromosomes: Megacephala megacephala and Prothyma lepneurii have 2n = 24+X,X 2 Y/ 24+X 1 X 1 X 2 X 2 , Euryarthron festwum has 2n= 22+X ] X 2 Y/22+X 1 X 1 X 2 X 2 , Ropaloteres feisthameli has 2n = 20+X 1 X 2 X,X 4 Y/20+XiX 1 X 2 X 2 X 3 X 3 X 4 X 4 and Hipparid-ium intenuptum has 2« = 20+X ] X 2 X 3 Y/20+XjX 1 X 2 X2X3X 3 . The existence of 12 pairs of autosomes in tribe Cicindelini is reported for the first time, being found in the genus Prothyma, the most ancient genus of this tribe. This supports the hypothesis that the chromosomal evolution in the Cicindelidae involved a reduction in number of chromosomes in the derived groups since the same number of autosomes or even more were found to occur in the most primitive tribes Collyrini and Megacephalini. All species have multiple sex chromosomes, apparently a characteristic of this family. Ropaloteres feisthameli has a sex chromosome system with four X chromosomes, only described for Cicindela maroccana pseudomar-occana and Cylindera trisignata.

Cytogenetic variability in three species of the genus Cicindela (s.l.) (Coleoptera, Cicindelidae): karyotypes and localization of 18S rDNA genes

“…species so far described the number of autosomal pairs (9) remains unchanged while the number of heterosomes varies from two to four, as in the species now analyzed. Conversely, some African, Australian and Oriental Cicindelini species have 10, 11 and 12 autosomal pairs and share the same number of heterosomes (Galián and Hudson, 1999;Proença et al, 1999). Moreover, the absence of chiasmata between the sex chromosomes may constitute a barrier for the translocation of chromosomal material between the chromosomes.…”

“…The direction in which diploid chromosome numbers and distinct sex chromosome determination systems have changed during karyotype evolution in tiger beetles can be determined by phylogenetic and cytogenetic analyses (Vogler and Pearson, 1996;Galián and Hudson, 1999;Proença et al, 1999Proença et al, , 2002aGalián et al, 2002). Apparently, there has been a reduction in the number of autosomal pairs from the most plesiomorphic groups to the most derived groups, with the genus Cicindela (s.l.)…”

New contributions to the cytotaxonomy of tiger beetles (Coleop-tera, Cicindelidae) from the Afrotropical Region: cytogenetic characterization of Prothyma concinna, Elliptica lugubris and Ropaloteres cinctus

“…Also, there are some biogeographic regions still with very few available data, like the Australian (Galian and Hudson 1999) and the Afrotropical (Proença et al 1999b) ones.…”

“…Cytogenetic studies in tiger beetles have shown the presence of an unique and diverse multiple sex chromosome system, XnY, where n varies from two to four, that forms a non-chiasmatic multivalent during meiosis linked by telomeric connections (for revision see Galiá n et al 1990;Serrano and Galiá n 1998;Proença et al 1999b).…”

“…The number of autosome pairs seems to gradually decrease from the most basal taxa (Manticorini and Omini) to the most derived ones, with an apparently stability at 9 pairs of autosomes in the large genus Cicindela (s.l.) (Serrano and Galiá n 1998;Proença et al 1999b).…”