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Integrative phylogeography of Calotriton newts (Amphibia, Salamandridae), with special remarks on the conservation of the endangered Montseny brook newt (Calotriton arnoldi).

Valbuena-Ureña E, Amat F, Carranza S - PLoS ONE (2013)

Bottom Line: SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species.Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper.The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability.

View Article: PubMed Central - PubMed

Affiliation: Unitat de Zoologia (Facultat de Biociències), Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Catalonia, Spain. emiliojavier.valbuena@uab.cat

ABSTRACT
The genus Calotriton includes two species of newts highly adapted to live in cold and fast-flowing mountain springs. The Pyrenean brook newt (Calotriton asper), restricted to the Pyrenean region, and the Montseny brook newt (Calotriton arnoldi), endemic to the Montseny massif and one of the most endangered amphibian species in Europe. In the present manuscript, we use an integrative approach including species distribution modeling (SDM), molecular analyses of mitochondrial and nuclear DNA sequence data and morphology to unravel the historical processes that have contributed to shaping the biogeography and genetic structure of the genus Calotriton, with special emphasis on the conservation of C. arnoldi. The results of the molecular analyses confirm that, despite having originated recently, being ecologically similar and geographically very close, there is no signal of hybridization between C. asper and C. arnoldi. SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species. Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper. Haplotype networks, AMOVA and SAMOVA analyses suggest that two distinct groups of populations can be clearly differentiated with absence of gene flow. This is in concordance with morphological differentiation and correlates with its geographical distribution, as the two groups are situated on the eastern and western sides of a river valley that acts as a barrier. The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability.

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Map showing the geographical distribution of Cyt b DNA haplotypes.(A) Pie diagram size indicates number of individuals. (B) Statistical parsimony networks showing cytochrome b haplotypes found for Calotriton arnoldi (left) and C. asper (right); circle size are proportional to haplotype abundance, straight lines and black dots reflect mutations and unsampled or extinct haplotype.
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pone-0062542-g002: Map showing the geographical distribution of Cyt b DNA haplotypes.(A) Pie diagram size indicates number of individuals. (B) Statistical parsimony networks showing cytochrome b haplotypes found for Calotriton arnoldi (left) and C. asper (right); circle size are proportional to haplotype abundance, straight lines and black dots reflect mutations and unsampled or extinct haplotype.

Mentions: The final mtDNA data set included 374 bp of the cyt b gene (24 variable and 22 parsimony-informative positions). The nDNA data set included 530 bp (6 variable positions, all of them parsimony-informative). Of the 12 cyt b haplotypes identified, 8 were found in C. asper and 4 in C. arnoldi (Figure 2), whereas of the 5 RAG-1 haplotypes found, 2 corresponded to C. asper and 3 to C. arnoldi (Figure 3). The number of individuals sequenced and occurrences of each haplotype per sampling site are given in Table 1. The sequences of all mitochondrial and nuclear haplotypes have been deposited in GenBank: accession numbers KC665954–KC665970. The number of haplotypes (h) and variable sites (S), and estimates of nucleotide (Π) and haplotype (Hd) diversity for each marker in each sampled species are shown in Table 3. For the mtDNA, similar levels of Π and Hd were observed, being slightly higher for C. asper than C. arnoldi. Instead, for the nDNA both values were, on average, higher for C. arnoldi. Within the Montseny brook newt, all 42 specimens from the western sector corresponded to the same unique haplotype for both mitochondrial and nuclear markers, thus Π and Hd were .


Integrative phylogeography of Calotriton newts (Amphibia, Salamandridae), with special remarks on the conservation of the endangered Montseny brook newt (Calotriton arnoldi).

Valbuena-Ureña E, Amat F, Carranza S - PLoS ONE (2013)

Map showing the geographical distribution of Cyt b DNA haplotypes.(A) Pie diagram size indicates number of individuals. (B) Statistical parsimony networks showing cytochrome b haplotypes found for Calotriton arnoldi (left) and C. asper (right); circle size are proportional to haplotype abundance, straight lines and black dots reflect mutations and unsampled or extinct haplotype.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3672179&req=5

pone-0062542-g002: Map showing the geographical distribution of Cyt b DNA haplotypes.(A) Pie diagram size indicates number of individuals. (B) Statistical parsimony networks showing cytochrome b haplotypes found for Calotriton arnoldi (left) and C. asper (right); circle size are proportional to haplotype abundance, straight lines and black dots reflect mutations and unsampled or extinct haplotype.
Mentions: The final mtDNA data set included 374 bp of the cyt b gene (24 variable and 22 parsimony-informative positions). The nDNA data set included 530 bp (6 variable positions, all of them parsimony-informative). Of the 12 cyt b haplotypes identified, 8 were found in C. asper and 4 in C. arnoldi (Figure 2), whereas of the 5 RAG-1 haplotypes found, 2 corresponded to C. asper and 3 to C. arnoldi (Figure 3). The number of individuals sequenced and occurrences of each haplotype per sampling site are given in Table 1. The sequences of all mitochondrial and nuclear haplotypes have been deposited in GenBank: accession numbers KC665954–KC665970. The number of haplotypes (h) and variable sites (S), and estimates of nucleotide (Π) and haplotype (Hd) diversity for each marker in each sampled species are shown in Table 3. For the mtDNA, similar levels of Π and Hd were observed, being slightly higher for C. asper than C. arnoldi. Instead, for the nDNA both values were, on average, higher for C. arnoldi. Within the Montseny brook newt, all 42 specimens from the western sector corresponded to the same unique haplotype for both mitochondrial and nuclear markers, thus Π and Hd were .

Bottom Line: SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species.Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper.The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability.

View Article: PubMed Central - PubMed

Affiliation: Unitat de Zoologia (Facultat de Biociències), Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Catalonia, Spain. emiliojavier.valbuena@uab.cat

ABSTRACT
The genus Calotriton includes two species of newts highly adapted to live in cold and fast-flowing mountain springs. The Pyrenean brook newt (Calotriton asper), restricted to the Pyrenean region, and the Montseny brook newt (Calotriton arnoldi), endemic to the Montseny massif and one of the most endangered amphibian species in Europe. In the present manuscript, we use an integrative approach including species distribution modeling (SDM), molecular analyses of mitochondrial and nuclear DNA sequence data and morphology to unravel the historical processes that have contributed to shaping the biogeography and genetic structure of the genus Calotriton, with special emphasis on the conservation of C. arnoldi. The results of the molecular analyses confirm that, despite having originated recently, being ecologically similar and geographically very close, there is no signal of hybridization between C. asper and C. arnoldi. SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species. Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper. Haplotype networks, AMOVA and SAMOVA analyses suggest that two distinct groups of populations can be clearly differentiated with absence of gene flow. This is in concordance with morphological differentiation and correlates with its geographical distribution, as the two groups are situated on the eastern and western sides of a river valley that acts as a barrier. The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability.

Show MeSH
Related in: MedlinePlus