Differences in gene flow in a twofold secondary contact zone of pond turtles in southern Italy (Testudines: Emydidae: Emys orbicularis galloitalica, E. o. hellenica, E. trinacris). (30th January 2015)

• Record Type: Journal Article
• Authors: Vamberger, Melita; Stuckas, Heiko; Sacco, Francesco; D'Angelo, Stefania; Arculeo, Marco; Cheylan, Marc; Corti, Claudia; Lo Valvo, Mario; Marrone, Federico; Wink, Michael; Fritz, Uwe
• Is Part Of: Zoologica scripta. Volume 44:Number 3(2015:May)
• Page Start: 233
• Page End: 249
• Publication Date: 2015-01-30
• Subjects: Zoology -- Periodicals; 590.5
• DOI: 10.1111/zsc.12102
• Languages: English
• ISSNs: 0300-3256

Abstract

<abstract abstract-type="main" id="zsc12102-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Using virtually range‐wide sampling for three pond turtle taxa (<italic>Emys orbicularis galloitalica</italic>, <italic> E. o. hellenica</italic>, <italic> E. trinacris</italic>), we analyse gene flow across their southern Italian contact zone. Based on population genetic analyses of 15 highly polymorphic microsatellite loci and a mitochondrial marker, we show that the general genetic pattern matches well with the current taxon delimitation. Yet, single individuals with conflicting genetic identity suggest translocation of turtles by humans. In addition, we identify in south‐western France and the vicinity of Rome populations being heavily impacted by introduced turtles. Cline analyses reveal that the major genetic break between <italic>E. o. galloitalica</italic> and <italic>E. o. hellenica</italic> corresponds well with the currently accepted intergradation zone in southern Italy. However, introgression is largely unidirectional from <italic>E. o. galloitalica</italic> into <italic>E. o. hellenica</italic>. In the distribution range of the latter subspecies, genetic footprints of <italic>E. o. galloitalica</italic> are evident along most of the Italian east coast. Our results corroborate that <italic>E. o. galloitalica</italic> was introduced long ago in Corsica and Sardinia and naturalized there. Gene flow between <italic>E. orbicularis</italic> and <italic>E. trinacris</italic> is negligible, with the Strait of Messina matching well with the narrow cline centre between the two species. This contrasts with other Mediterranean freshwater turtle species with extensive transoceanic gene flow. Compared to the two subspecies of <italic>E. orbicularis</italic>, the Sicilian <italic>E. trinacris</italic> shows an unexpectedly strong population structuring, a finding also of some relevance for conservation. The differences between the two taxon pairs <italic>E. orbicularis/E. trinacris</italic> and <italic>E. o. galloitalica/E. o. hellenica</italic> support their current taxonomic classification and make them attractive objects for follow‐up studies to elucidate the underlying mechanisms of speciation by comparing their properties.</p> </abstract>