Molecular cytogenetics of Androctonus scorpions: an oasis of calm in the turbulent karyotype evolution of the diverse family Buthidae

• Published in: Biological journal of the Linnean Society Vol. 115; no. 1; pp. 69 - 76
• Main Authors: Sadílek, David, Nguyen, Petr, Koç, Halіl, Kovařík, František, Yağmur, Ersen Aydin, Šťáhlavský, František
• Format: Journal Article
• Language: English
• Published: Oxford Published for the Linnean Society of London by Blackwell [etc.] 01-05-2015; Blackwell Publishing Ltd; Oxford University Press
• Subjects: 18S rDNA; Androctonus; Androctonus australis; Androctonus crassicauda; Buthidae; Chromosomes; evolution; FISH; fluorescence in situ hybridization; genes; genomics; holocentric chromosomes; holokinetic drive; Karyotypes; karyotyping; loci; multivalent association; oases; ribosomal DNA; ribosomal RNA; Scorpiones; Speciation
• ISSN: 0024-4066; 1095-8312
• DOI: 10.1111/bij.12488

Recent cytogenetic and genomic studies suggest that morphological and molecular evolution is decoupled in the basal arachnid order Scorpiones. Extraordinary karyotype variation has been observed particularly in the family Buthidae, which is unique among scorpions for its holokinetic chromosomes. We analyzed the karyotypes of four geographically distant species of the genus Androctonus Ehrenberg, 1828 (Androctonus australis, Androctonus bourdoni, Androctonus crassicauda, Androctonus maelfaiti) (Scorpiones: Buthidae) using both classic and molecular cytogenetic methods. The mitotic complement of all species consisted of 2n = 24 elements. Fluorescence in situ hybridization with a fragment of the 18S ribosomal RNA gene, a cytogenetic marker well known for its mobility, identified a single interstitial rDNA locus on the largest chromosome pair in all species examined. Our findings thus support the evolutionary stasis of the Androctonus karyotype, which is discussed with respect to current hypotheses on chromosome evolution both within and beyond the family Buthidae. Differences in karyotype dynamics between Androctonus spp. and the other buthids can help us better understand the driving forces behind their chromosome evolution and speciation. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115, 69–76.