Chromosome evolution in pseudoxyrhophiine snakes from Madagascar: a wide range of karyotypic variability. (4th June 2014)

• Record Type: Journal Article
• Authors: Mezzasalma, Marcello; Andreone, Franco; Branch, William R.; Glaw, Frank; Guarino, Fabio M.; Nagy, Zoltán T.; Odierna, Gaetano; Aprea, Gennaro
• Is Part Of: Biological journal of the Linnean Society. Volume 112:Number 3(2014:Jul.)
• Page Start: 450
• Page End: 460
• Publication Date: 2014-06-04
• Subjects: Biology -- Periodicals; Evolution (Biology) -- Periodicals; 570
• DOI: 10.1111/bij.12280
• Languages: English
• ISSNs: 0024-4066

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>In this first cytogenetic survey on the lamprophiid snake subfamily Pseudoxyrhophiinae, we studied the karyology of ten snake species belonging to seven genera from Madagascar (<italic>Compsophis</italic>, <italic>Leioheterodon</italic>, <italic>Liophidium</italic>, <italic>Lycodryas</italic>, <italic>Madagascarophis</italic>, <italic>Phisalixella</italic> and <italic>Thamnosophis</italic>) using standard and banding methods. Our results show a wide range of different karyotypes ranging from 2<italic>n</italic> = 34 to 2<italic>n</italic> = 46 elements (FN from 40 to 48), with nucleolus organizer regions (NORs) on one (plesiomorphic) or two (derived/apomorphic) microchromosome pairs, and W chromosome at early or advanced states of diversification from the Z chromosome. The observed W chromosome variations further support the most accepted hypothesis that W differentiation from the Z chromosome occurred by progressive steps. We also propose an evolutionary scenario for the observed high karyotype diversity in this group of snakes, suggesting that it is derived from a putative primitive pseudoxyrhophiine karyotype with 2<italic>n</italic> = 46, similar to that of <italic>Leioheterodon geayi</italic>, via a series of centric fusions and inversions among macrochromosomes and translocations of micro‐ either to micro‐ or to macrochromosomes. This primitive Pseudoxyrhophiinae karyotype might have derived from a putative Lamprophiidae ancestor with 2<italic>n</italic> = 48, by means of a translocation of a micro‐ to a macrochromosome. In turn, the karyotype of this lamprophiid common ancestor may have derived from the assumed primitive snake karyotype (2<italic>n</italic> = 36 chromosomes, with 16 biarmed macro‐ and 20 microchromosomes) by a series of centric fissions and one inversion. © 2014 The Linnean Society of London, <italic>Biological Journal of the Linnean Society</italic>, 2014, <bold>112</bold>, 450–460.</p> </abstract>