Molecular identification of the samples SPS1, MGS1, MGS2, MGS3, SES1, SES2, and SES3 using the nuclear <i>tpm1</i> (a) and mitochondrial <i>mt-co1</i> (b) genes in multiplex-PCR.

<p>Lanes 1–12, genotypes of hybrid tambacu (♀ tambaqui x ♂ pacu); and lanes 13, 14, and 15, control DNA samples from the pure pacu, tambaqui, and pirapitinga species, respectively; M, 1 Kb Plus DNA Ladder.</p

Schematic representation of the events of crossing-over and the fusion/retention of the second polar body, which likely generated the triploid individual of genotype E.

<p>Schematic representation of the events of crossing-over and the fusion/retention of the second polar body, which likely generated the triploid individual of genotype E.</p

Metaphases and the respective karyotypes of individuals of the SPS2 stock, showing the chromosome location of the 5S rRNA clusters.

<p>The arrows and arrowheads indicate the 5S rRNA major and minor clusters, respectively, in metaphase. In the karyotypes, the green bars indicate the chromosomes bearing 5S rRNA genes and their respective locations (long or short arms). (a) an individual of genotype A, (b) an individual of genotype B, and (c) an individual of genotype E.</p

Image2.tif

<p>Evidence that migration prevents population structure among Neotropical characiform fishes has been reported recently but the effects upon species diversification remain unclear. Migratory species of Prochilodus have complex species boundaries and intrincate taxonomy representing a good model to address such questions. Here, we analyzed 147 specimens through barcode sequences covering all species of Prochilodus across a broad geographic area of South America. Species delimitation and population genetic methods revealed very little genetic divergence among mitochondrial lineages suggesting that extensive gene flow resulted likely from the highly migratory behavior, natural hybridization or recent radiation prevent accumulation of genetic disparity among lineages. Our results clearly delimit eight genetic lineages in which four of them contain a single species and four contain more than one morphologically problematic taxon including a trans-Andean species pair and species of the P. nigricans group. Information about biogeographic distribution of haplotypes presented here might contribute to further research on the population genetics and taxonomy of Prochilodus.</p

Schematic representation of the backcrossing between ♂ tambaqui x ♀ patinga (♀ pacu x ♂ pirapitinga), demonstrating the <i>tpm1</i> and <i>rag2</i> gene loci and the expected probability of each genotype.

<p>Schematic representation of the backcrossing between ♂ tambaqui x ♀ patinga (♀ pacu x ♂ pirapitinga), demonstrating the <i>tpm1</i> and <i>rag2</i> gene loci and the expected probability of each genotype.</p

Sizes of the PCR products or restriction fragments, according to Hashimoto et al. [12].

<p>Sizes of the PCR products or restriction fragments, according to Hashimoto et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0089902#pone.0089902-Hashimoto3" target="_blank">[12]</a>.</p

Table1.DOC

<p>Evidence that migration prevents population structure among Neotropical characiform fishes has been reported recently but the effects upon species diversification remain unclear. Migratory species of Prochilodus have complex species boundaries and intrincate taxonomy representing a good model to address such questions. Here, we analyzed 147 specimens through barcode sequences covering all species of Prochilodus across a broad geographic area of South America. Species delimitation and population genetic methods revealed very little genetic divergence among mitochondrial lineages suggesting that extensive gene flow resulted likely from the highly migratory behavior, natural hybridization or recent radiation prevent accumulation of genetic disparity among lineages. Our results clearly delimit eight genetic lineages in which four of them contain a single species and four contain more than one morphologically problematic taxon including a trans-Andean species pair and species of the P. nigricans group. Information about biogeographic distribution of haplotypes presented here might contribute to further research on the population genetics and taxonomy of Prochilodus.</p

Molecular identification of the SPS2 stock using the nuclear <i>tpm1</i> (a) and <i>rag2</i> (b) genes, and mitochondrial <i>mt-co1</i> (c) and <i>mt-cyb</i> (d) genes.

<p>Lanes 4, 11, and 12, genotype A; lane 5, genotype B; lanes 3, 6, and 7, genotype C; lanes 1, 2, 9, and 10, genotype D; lane 8, genotype E; and lanes 13, 14, and 15, control DNA samples from the pure pacu, tambaqui, and pirapitinga species, respectively; M, 1 Kb Plus DNA Ladder.</p

Image1.tif

<p>Evidence that migration prevents population structure among Neotropical characiform fishes has been reported recently but the effects upon species diversification remain unclear. Migratory species of Prochilodus have complex species boundaries and intrincate taxonomy representing a good model to address such questions. Here, we analyzed 147 specimens through barcode sequences covering all species of Prochilodus across a broad geographic area of South America. Species delimitation and population genetic methods revealed very little genetic divergence among mitochondrial lineages suggesting that extensive gene flow resulted likely from the highly migratory behavior, natural hybridization or recent radiation prevent accumulation of genetic disparity among lineages. Our results clearly delimit eight genetic lineages in which four of them contain a single species and four contain more than one morphologically problematic taxon including a trans-Andean species pair and species of the P. nigricans group. Information about biogeographic distribution of haplotypes presented here might contribute to further research on the population genetics and taxonomy of Prochilodus.</p

BryconidaeNexus

Sequences of all Characiformes analyze