title: Comparative cytogenetics of seven Ctenidae species (Araneae).
abstract: The present study elevates the number of cytogenetically analyzed ctenid species and genera from two to eight and six, respectively, presenting comparisons between chromosomal data obtained and the phylogenetic hypothesis proposed in the literature. Six ctenid species presented 13 autosomal pairs, exhibiting either X1X2O (Ctenus ornatus, Ctenus sp., Parabatinga brevipes and Phoneutria nigriventer) or X1X2X3O sex chromosome systems (Nothroctenus sp. and Viracucha andicola). Asthenoctenus borellii showed 2n ♂ = 20 + X1X2O. In all species, the chromosomes were telocentric. Some cells of one C. ornatus specimen exhibited one extra chromosome that, considering the behavioral similarities between the two chromosomes, can be considered to be supernumerary, derived from or giving rise to a sex chromosome. Silver impregnation revealed nucleolar organizer regions on one autosomal pair of C. ornatus and P. nigriventer (Cteninae) and two pairs of V. andicola (Acanthocteninae). Chromosomal data suggests that the X1X2X3O system arose several times in the evolution of entelegyne spiders, and that conversion of an X1X2O system into an X1X2X3O system and vice-versa has been a relatively common event in spiders. All the chromosomal data corroborate the close relationship between Ctenus and Phoneutria, the placement of P. brevipes within Cteninae, the placement of Anahita in a separated branch within Cteninae, and the inclusion of A. borellii in a distinct group within the ctenids (Viridasiinae), all of which are as proposed by phylogenetic hypotheses available in the literature.
authors: 1 Universidade Federal de Mato Grosso do Sul, U FM S, Setor de Biologia Geral, Centro de Ciências Biológicas e da Saúde, Cidade Universitária, Bairro Universitário, 79070-900, Campo Grande, Mato Grosso do Sul, Brazil.
authors: Douglas
authors: D
authors: Araujo
authors: Edson Gabriel
authors: EG
authors: de Oliveira
authors: André Marsola
authors: AM
authors: Giroti
authors: Viviane Fagundes
authors: VF
authors: Mattos
authors: Emygdio
authors: E
authors: Paula-Neto
authors: Antonio Domingos
authors: AD
authors: Brescovit
authors: Marielle Cristina
authors: MC
authors: Schneider
authors: Doralice Maria
authors: DM
authors: Cella
mesh_terms: D000818:Animals; D020732:Cytogenetic Analysis; D005260:Female; D059785:Karyotype; D008297:Male; D013112:Spiders / Q000235:genetics*