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Castiglia, R.

Publications and source records attributed to Castiglia, R..

2 recordsLinked to original sources

The Sicilian wolf: genetic identity of a recently extinct insular population

During historical times many local grey wolf (Canis lupus) populations underwent a substantial reduction of their sizes or became extinct. Among these, the wolf population once living in Sicily, the biggest island of the Mediterranean Sea, was completely eradicated by human persecution in the early decades of the XX century.\n\nIn order to understand the genetic identity of the Sicilian wolf, we applied ancient DNA techniques to analyse the mitochondrial DNA of six specimens actually stored in Italian museums.\n\nWe successfully amplified a diagnostic mtDNA fragment of the control region (CR) in four of the samples. Results showed that two samples shared the same haplotype, that differed by two substitutions from the currently most diffused Italian wolf haplotype (W14) and one substitution from the only other Italian haplotype (W16). The third sample showed a wolf-like haplotype never described before and the fourth a haplotype commonly found in dogs.\n\nFurthermore, all the wolf haplotypes detected in this study belonged to the mitochondrial haplogroup that includes haplotypes detected in all the known European Pleistocene wolves and in several modern southern European populations.\n\nUnfortunately, this endemic island population, bearing unique mtDNA variability, was definitively lost before it was possible to understand its taxonomic uniqueness and conservational value.

genetics

Spotlight on islands: on the origin and diversification of a new lineage of the Italian wall lizard Podarcis siculus in the western Pontine Islands

Groups of proximate continental islands may conceal more tangled phylogeographic patterns than oceanic archipelagos as a consequence of repeated sea level changes, which allow populations to experience gene flow during periods of low sea level stands and isolation by vicariant mechanisms during periods of high sea level stands. Here, we describe for the first time an ancient and diverging lineage of the Italian wall lizard Podarcis siculus from the western Pontine Islands. We used nuclear and mitochondrial DNA sequences of 156 individuals with the aim of unraveling their phylogenetic position, while microsatellite loci were used to compare several a priori insular biogeographic models of migration with empirical data. Our results suggest that the western Pontine populations colonized the islands early during their Pliocene volcanic formation, while populations from the eastern Pontine Islands seem to have been introduced recently. The inter-island genetic makeup indicates an important role of historical migration, probably due to glacial land bridges connecting islands followed by a recent vicariant mechanism of isolation. Moreover, the most supported migration model predicted higher gene flow among islands sharing a longitudinal arrangement. Considering the threatened status of small insular endemic populations, we suggest this new evolutionarily independent unit be given priority in conservation efforts.

evolutionary biology