Mitochondrial DNA variability in viviparous and ovoviviparous populations of the urodele Salamandra salamandra

Mitochondrial DNA analysis of 13 populations of S. salamandra along a transect across the North of the Iberian Peninsula showed values of divergence between haplotypes ranging from d = 0.41% to 5.91%. Phenetic and cladistic analysis grouped the isofemale lineages into two main clusters with contrasting phylogeographic patterns. The first group encompasses populations located at each extreme of the Iberian Peninsula. Despite the large geographic distance separating these populations, they exhibit only a minor degree of divergence among haplotypes. In contrast, much higher diversification, in both number of distinct haplotypes, and overall genetic divergence, was observed in the second group of phylogenetically related populations. Surprisingly, this process of radiation and divergence in mtDNA haplotypes occurred in populations in close geographic proximity. All populations sampled in this group are located within a 300 km range, in the central part of our transect across the Northern edge of the Peninsula. Most populations in the central range of our transect exhibit viviparous reproduction — which is derived and highly unusual among urodeles. The genetic distances measured among Asturian (central portion of our transect), viviparous populations are higher than the distances measured between the two main taxonomic clusters. A viviparous population showing an unusual level of mtDNA heterogenetiy is reported and the potential implications of this focus of localized variability are discussed. The dynamics of isofemale lineages among the two reproductive modes was further explored in combination with the previous allozyme data. Several nuclear markers suggest that major mtDNA divergences could be explained by long-term extrinsic barriers to gene flow. Isofemale lineages indicate a narrow secondary contact zone among populations with different reproductive patterns. The existence of viviparous and ovovivparous populations sharing a common haplotype suggests that reproductive transition in S. salamandra could have arisen in absence of genetic mtDNA differentiation. We finally outline a genetic model system where the acquisition of water independence from a primitively aquatic dependent amphibian life cycle can be analyzed from a microevolutionary perspective.     

Geographic variation in allozymes of populations of Salamandra salamandra (Amphibia: Urodela) exhibiting distinct reproductive modes

The populations of the urodele Salamandra salamandra in the Northern Iberian Peninsula exhibit very different coloration patterns and a remarkable range in reproductive modes (from giving birth to a large number of aquatic larvae to a parturition event of just a few fully metamorphosed, i.e. terrestrial, offspring). Electrophoretic study of geographic variation in allozymes shows that this extraordinary diversity, particularly in reproductive modes, is not accompanied by a genetic differentiation of similar magnitude. All the populations sampled along a transect crossing the Northern part of the Iberian Peninsula and encompassing the various reproductive strategies, as previously described, can be ascribed to a single species, because of small interpopulational genetic distances (ranging D_Nei from 0.05 to 0.199) and absence of fixed (diagnostic) alleles. A variety of phenetic and cladistic methods were used to elucidate the relationship among populations, based on allozyme data. These methods defined two well corroborated clusters: the first contains populations of salamanders with a blotched dorsal coloration pattern and characterized by parturition of aquatic larvae; the second group is composed of populations exhibiting a striped dorsal coloration pattern, smaller adult body size, and giving birth to fully metamorphosed terrestrial offspring. The latter group also encompasses some populations where mixed parturition events, which include both larvae and metamorphosed offspring, which have been recorded (Dopazo and Alberch, 1994). The absence of a correlation between genetic and geographic distance suggests that the mode of differentiation of the species is based on at least two successive events of isolation, radiation, and secondary contact between populations. Furthermore, the validity of the described “subspecies” is questioned by our data, which point out the need for a detailed systematic study of Salamandra from a global perspective. “Viviparity”, here meaning giving birth to fully metamorphosed offspring, originated once and occurs as intraspecific, and even as intrapopulational variation. Thus, we confirm a system where a major evolutionary innovation -the acquisition of independence from the aquatic media in the primitive amphibian complex life cycle-, can be studied at the microevolutionary, i.e., intra- and inter-populational level.     

Haplotype variation in a mitochondrial tandem repeat of Norway spruce (Picea abies) populations suggests a serious founder effect during postglacial re-colonization of the western Alps

Populations from 13 elevational transects of Norway spruce [Picea abies (L.) Karst] across the Alpine range were sampled to elucidate the geographical pattern of genetic variation in relation to postglacial re-colonization and to study elevational effects on haplotypic diversity. We assessed fragment length variation in a tandem repeat region of the mitochondrial (mt) nad1 intron 2. This maternally inherited genetic marker is suited to infer migration as it is dispersed by seed only. A total of 10 haplotypes was found, most of which were due to repeat copy number variation. An analysis of molecular variance (amova) showed that overall population differentiation was high (F(ST)=0.41), and it revealed a significant differentiation between monomorphic western and moderately to highly variable eastern Alpine populations. This phylogeographic pattern may be explained by a founder effect during postglacial re-colonization. An early arriving haplotype, assumed to originate from a western Carpathian refugium, could expand into suitable habitats, reducing the chances for establishment of subsequently arriving haplotypes. On the other hand, the high variation in populations within an Italian transect of the south-eastern Alps may be the consequence of merging migration pathways from and close distance to putative glacial refugia, most likely those assumed in the Carpathian mountains and on the Balkan peninsula or possibly in the central plains of Italy. An effect of elevation on haplotypic diversity was not evident, though a low, but significant, partition of total genetic variation was attributed to among-population variation in one Italian transect. Various factors, such as vertical seed dispersal and forest management, may account for blurring an otherwise established pattern of genetic variation on a small geographical scale.     

Phylogeography and postglacial expansion of Mus musculus domesticus inferred from mitochondrial DNA coalescent, from Iran to Europe

Few genetic data document the postglacial history of the western house mouse, Mus musculus domesticus. We address this by studying a sample from the southeastern tip of the Fertile Crescent in the Iranian province of Ahvaz. Including other published and unpublished data from France, Germany, Italy, Bulgaria, Turkey and other places in Iran, altogether 321 mitochondrial D-loop sequences are simultaneously analysed. The patterns of coalescence obtained corroborate the classical proposal according to which the Fertile Crescent is where commensalism with humans has started in the Western Hemisphere, and from where the subspecies has expanded further west. Our data also clearly show that despite multiple colonisations and long-range transportation, there is still a rather high PhiST of 0.39. The original expansion signal is still recognisable, with two well-separated derived clades, allowing us to propose a hypothetical scenario in which expansion toward Europe and Asia Minor took at least two routes, tentatively termed the Mediterranean and the Bosphorus/Black Sea routes. This scenario resembles that of another domesticated species, the goat, and fits with the known progression of Neolithic culture. Given the concomitance of both phenomena around 12,000 years ago, we propose a recalibration of the D-loop mutation rate to a much faster tick of approximately 40% per site per million years (Myr). This value should be used for intrasubspecific polymorphism, while the interspecific rate in Mus is presently estimated at 6-10%/site/Myr. This is in keeping with the now well recognised fact that only a subfraction of segregating mutations go to fixation.     

Phylogeographic analysis of pigtail macaque populations (Macaca nemestrina) inferred from mitochondrial DNA

Mitochondrial DNA variation was surveyed in nine populations of the pigtail macaque (Macaca nemestrina), covering all three recognized subspecies in Southeast Asia. To do this, a 2,300 base pair fragment spanning the mitochondrial NAD 3 and NAD 4 genes and flanking tRNA subunits leucine and glycine was targeted for amplification and digested with a battery of 16 restriction endonucleases. Out of a total of 107 individuals, 32 unique haplotypes could be distinguished. Parsimony and neighbor-joining analyses grouped the haplotypes into five strongly supported assemblages representing China/Thailand, Malaysia, Sumatra, Borneo, and Siberut. These results indicate that the mainland and island mtDNA haplotypes are strictly and uniquely limited to the geographic ranges of the recognized morphological subspecies. Cladistic and neighbor-joining analyses indicate that inferred phylogenies of mtDNA haplotypes are congruent with subspecies designations. Furthermore, in support of morphological studies, results indicate that the Mentawai macaque is most likely not a distinct species but a subspecies of M. nemestrina. Am J Phys Anthropol 104:35–45, 1997. © 1997 Wiley-Liss, Inc.     

Phylogeographic analyses reveal distinct lineages of the liverworts Metzgeria furcata (L.) Dumort. and Metzgeria conjugata Lindb. (Metzgeriaceae) in Europe and North America

Seed plant genera often exhibit intercontinental disjunctions where different species are found on different continents. Many morphologically circumscribed bryophyte species exhibit similar disjunctions. We used nucleotide sequences from the plastid and nuclear genomes to test hypotheses of phylogeography within representatives of the genus Metzgeria: Metzgeria furcata, Metzgeria conjugata, and Metzgeria myriopoda. The first two species have sexual and asexual populations, exhibit disjunctions between North America and Europe, and have been split into separate species, numerous subspecies or varieties. The third species occurs in eastern North America but is not reported from Europe. Phylogenetic analyses resolved three distinct lineages within the morphologically defined species, M. furcata: one in North America, and two in Europe. Similarly, three morphologically cryptic clades of M. conjugata were resolved by the molecular data: northern North America, Europe, and south‐eastern North America. For both species, molecular divergence among taxa occurred in the absence of morphological change. In the case of M. myriopoda, all plants from eastern North America were both morphologically uniform and genetically homogeneous (although not identical). The present study provides significant insight into a plant group with complex taxonomy, and indicates that these liverwort taxa with wide distributions, extreme sex ratios, and continental disjunctions harbor cryptic lineages. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 745–756.     

Phylogenetic analysis of the genus Sorghum based on combined sequence data from cpDNA regions and ITS generate well-supported trees with two major lineages

Background and Aims

Wild Sorghum species provide novel traits for both biotic and abiotic stress resistance and yield for the improvement of cultivated sorghum. A better understanding of the phylogeny in the genus Sorghum will enhance use of the valuable agronomic traits found in wild sorghum.

Methods

Four regions of chloroplast DNA (cpDNA; psbZ-trnG, trnY-trnD, trnY-psbM and trnT-trnL) and the internal transcribed spacer (ITS) of nuclear ribosomal DNA were used to analyse the phylogeny of sorghum based on maximum-parsimony analyses.

Key Results

Parsimony analyses of the ITS and cpDNA regions as separate or combined sequence datasets formed trees with strong bootstrap support with two lineages: the Eu-sorghum species S. laxiflorum and S. macrospermum in one and Stiposorghum and Para-sorghum in the other. Within Eu-sorghum, S. bicolor-3, -11 and -14 originating from southern Africa form a distinct clade. S. bicolor-2, originally from Yemen, is distantly related to other S. bicolor accessions.

Conclusions

Eu-sorghum species are more closely related to S. macrospermum and S. laxiflorum than to any other Australian wild Sorghum species. S. macrospermum and S. laxiflorum are so closely related that it is inappropriate to classify them in separate sections. S. almum is closely associated with S. bicolor, suggesting that the latter is the maternal parent of the former given that cpDNA is maternally inherited in angiosperms. S. bicolor-3, -11 and -14, from southern Africa, are closely related to each other but distantly related to S. bicolor-2.     

不同产地瓠瓜品种ITS序列的遗传多样性分析

对国产29个瓠瓜也Lagenariasiceraria（Molina）Standl.页品种的ITS序列进行了扩增及测序,并结合引自GenBank的国产9个瓠瓜品种以及国外6个瓠瓜品种和3个同属种类的ITS序列,对它们的ITS序列长度和GC含量以及变异位点进行比较,在此基础上构建系统发育树并对47个样本间的遗传关系进行研究。结果显示：供试47个样本的ITS序列均由ITS1、5.8SrDNA及ITS2组成,各样本间的ITS序列长度、GC含量以及变异位点差异明显。国产38个瓠瓜品种的ITS序列（包括ITS1、5.8SrDNA及ITS2）长度为619-627bp、GC含量为58.00%-63.32%;国外9个样本的ITS序列长度为591-626bp,GC含量为54.17%-63.26%。序列比对结果显示：国产38个瓠瓜品种的ITS序列同源率为84.6%-100.0%,包含221个变异位点;其中,来源于山东的品种‘砧木2’（‘ZhenmuNo.2’）的ITS序列包含的变异位点最多,与其他品种间的同源率也最低。在系统发育树上,国产38个瓠瓜品种可分为3个分支,来源于山东的品种‘砧木2’和来源于河南的品种‘西瓜砧木1’（‘XiguazhenmuNo.1’）各自聚为第1和第2分支;其余36个品种聚为第3分支。而供试的47个样本则可分为2个分支和5个亚组,第1分支可分为2个亚组,包括国产品种‘砧木2’和产自日本的2个品种;第2分支包含的44个样本则进一步分为3个亚组,国产品种‘西瓜砧木1’和产自法国的品种‘白花瓠瓜’（‘White-floweredgourd’）各自聚为第1和第2亚组,其余的42个样本聚为第3亚组。研究结果表明：供试的不同产地瓠瓜品种间存在丰富的遗传变异和地理分化现象,其ITS序列差异与地理分布有一定关系。     

SE- and SW-migrating Blackcap (Sylvia atricapilla) populations in Central Europe: Orientation of birds in the contact zone

In the Blackcap (Aves: Sylvia atricapilla), a widespread passerine noctural migrant, a “migratory divide” between SE- and SW-migrating populations exists in Central Europe at about 14° E and south of 52° N. The autumn migratory directions are known to have a genetic basis and are expressed in orientation cages in captivity. Migratory directions of birds in the contact zone between the two populations were studied by analysing ringing data and by testing three groups of hand-raised individuals in orientation cages. Available ringing data are insufficient to establish migratory directions in the contact zone north of the Alps. Hand-raised birds from south-west Germany and the most eastern part of Austria oriented SW and SE, respectively, confirming directions known from ringing recoveries. A sample of birds from the contact zone near Linz (Austria) oriented SW to NW (mean = 268°) and was significantly different from both adjoining populations. This contrasts with results of a cross-breeding experiment with mixed pairs of SW- and SE-migrants bred in captivity: The F1-offspring chose southerly directions, intermediate between both parental populations (Helbig, 1991). It is suggested, therefore, that a distinct subpopulation with a large fraction of birds wintering in the British Isles has established itself in the contact zone. Differences in directional choices between groups of siblings from this area indicate that intrapopulation genetic variability is present. This may have led to a rapid spread of the novel W-NW migratory direction, because north of the Alps strong selection seems to be acting against mixing of SE- with SW-migrating populations.     

Multiple origins of Locusta migratoria (Orthoptera: Acrididae) in the Japanese Archipelago and the presence of two major clades in the world: evidence from a molecular approach

Phylogenetic relationships among migratory locust (Locusta migratoria) populations in different climatic regions were analysed by sequencing four mitochondrial DNA regions, with special reference to the origin of Japanese populations. The populations are clearly separated into two clades: one consists of individuals from temperate and cold‐temperate areas of Japan and the Chinese continent, and the other comprises those from subtropical islands of Japan, Hainan Island in China, Timol Leste, Australia, Ethiopia, France, and some individuals from Tsushima Island and Honshu of Japan. The divergence time between the two clades is estimated to be 0.86–1.89 Mya. The phylogenetic analysis revealed that Japanese L. migratoria populations were composed of individuals of six different origins: (1) Hokkaido populations possibly from the Russian continent; (2) Honshu–Kyushu populations from the Chinese continent; (3) Southwest Island populations from Hainan Island or adjacent areas; (4) Ogasawara populations that might have originated from Micronesia; (5) part of the Tsushima population that originated from somewhere in the Asian tropics; and (6) a possible relict population of ancient southern haplotypes that exists in western areas of northern Honshu. The Tsugaru Straits and Tokara Straits have acted as effective geographical barriers, as in other organisms, isolating locust populations for a few thousand years. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 570–581.     

Evidence from peptidomic analysis of skin secretions that allopatric populations of Xenopus gilli (Anura:Pipidae) constitute distinct lineages

The International Union for Conservation of Nature (IUCN) Endangered Cape Platanna Xenopus gilli inhabits disjunct ranges at the tip of Cape Peninsula and near the town of Kleinmond on opposite sides of False Bay in the extreme southwest of Africa. Peptidomic analysis of host-defense peptides in norepinephrine-stimulated skin secretions from frogs from the Cape Peninsula range resulted in the identification of two magainins, two peptide glycine–leucine–amide (PGLa) peptides, two xenopsin-precursor fragment (XPF) peptides, nine caerulein-precursor fragment (CPF) peptides, and a peptide related to peptide glycine–glutamine (PGQ) previously found in an extract of Xenopus laevis stomach. The primary structures of the peptides indicate a close phylogenetic relationship between X. gilli and X. laevis but only magainin-1, PGLa and one CPF peptide are identical in both species. Consistent with previous data, the CPF peptides show the greatest antimicrobial potency but are hemolytic. There are appreciable differences in the expression of host-defense peptide genes in frogs from the population of animals sampled near Kleinmond as peptides corresponding to magainin-G2, XPF-G1, XPF-G2, and four CPF peptides, present in secretions from the Cape Peninsula frogs, were not identified in the skin secretions from Kleinmond frogs. Conversely, PGLa-G3, XPF-G3, and three CPF peptides were identified in the Kleinmond frogs but not in the Cape Peninsula animals. The data support the conclusion from morphometric analyses and comparisons of the nucleotide sequences of mitochondrial genes that the disjunct populations of X. gilli have undergone appreciable genetic, morphological, and phenotypic divergence.     

Fossil water‐penny beetles (Coleoptera: Psephenidae: Eubrianacinae) from the Eocene of Europe,with remarks on their phylogenetic position and biogeography

Abstract: A species of water‐penny beetles is recorded from larval instars from the Middle Eocene Messel pit fossil site in Germany. This species clearly belongs to the psephenid subfamily Eubrianacinae, but its precise systematic affinities remain unclear. It is the second fossil species of this taxon recorded from Europe. The holotype of the first fossil species, Eubrianax vandeli Bertrand and Laurentiaux, 1963, is lost. The high number of fossil specimens from Messel allowed discussion of stratigraphic and spatial occurrence of the eubrianacine species in the Messel pit, but its larval ontogeny could not be unravelled. Because of the high number of fossils and their wide occurrence, it is inferred that the species from Messel gen. sp. 1 was an autochthonous faunal element of the Eocene Lake Messel, which might indicate that some parts of the former Lake Messel had a shore area with stones. The analysis of the phylogenetic position of both Eocene eubrianacine species showed that their phylogenetic placement cannot be resolved because preservational influences limit the evaluation of characters. The historical biogeography of Psephenidae and Eubrianacinae is analysed and discussed. The fossil record shows that psephenid beetles have fossil members occurring outside their current distribution range, so interpretations of their biogeography based only on extant members can be misleading.     

Genetic diversity and differentiation of guanaco populations from Argentina inferred from microsatellite data

Genotype data from 14 microsatellite markers were used to assess the genetic diversity and differentiation of four guanaco populations from Argentine Patagonia. These animals were recently captured in the wild and maintained in semi-captivity for fibre production. Considerable genetic diversity in these populations was suggested by the finding of a total of 162 alleles, an average mean number of alleles per locus ranging from 6.50 to 8.19, and H(e) values ranging from 0.66 to 0.74. Assessment of population differentiation showed moderate but significant values of F(ST)=0.071 (P=0.000) and R(ST)=0.083 (P=0.000). An amova test showed that the genetic variation among populations was 5.6% while within populations it was 94.4%. A number of 6.6 migrants per generation may support these results. Unambiguous individual assignment to original populations was obtained for the Pilcaniyeu, Las Heras and La Esperanza populations. The erroneous assignment of 18.75% Rio Mayo individuals to the Las Heras population can be explained by the low genetic differentiation found between these two populations. Thirty-nine of 56 loci per population combinations were in Hardy--Weinberg disequilibrium because of guanaco heterozygote deficiency, which may be explained by population subdivision. The high level of genetic diversity of the guanacos analysed here indicates that the Patagonian guanaco constitutes an important genetic resource for conservation or economic utilization programmes.     

Sophora sect. Edwardsia (Fabaceae): further evidence from nrDNA sequence data of a recent and rapid radiation around the Southern Oceans

Phylogenetic relationships are inferred from nuclear ribosomal internal transcribed spacer sequences for species belonging to Sophora sect. Edwardsia from South America, New Zealand, Lord Howe Island, Hawai'i, La Réunion, Easter Island, and Raivavae Island (French Polynesia). Results support the monophyly of sect. Edwardsia , but relationships among the species from this section are poorly resolved due to most species having identical sequences. The origin of Sophora sect. Edwardsia is discussed, as competing hypotheses have proposed the group originated in South America from a North American ancestor, or in the north-west Pacific. We suggest sect. Edwardsia may have arisen in the north-west Pacific from a Eurasian ancestor.  © The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 140 , 435–441.     

Communally breeding Bechstein's bats have a stable social system that is independent from the postglacial history and location of the populations

Investigating macro-geographical genetic structures of animal populations is crucial to reconstruct population histories and to identify significant units for conservation. This approach may also provide information about the intraspecific flexibility of social systems. We investigated the history and current structure of a large number of populations in the communally breeding Bechstein's bat ( Myotis bechsteinii ). Our aim was to understand which factors shape the species' social system over a large ecological and geographical range. Using sequence data from one coding and one noncoding mitochondrial DNA region, we identified the Balkan Peninsula as the main and probably only glacial refugium of the species in Europe. Sequence data also suggest the presence of a cryptic taxon in the Caucasus and Anatolia. In a second step, we used seven autosomal and two mitochondrial microsatellite loci to compare population structures inside and outside of the Balkan glacial refugium. Central European and Balkan populations both were more strongly differentiated for mitochondrial DNA than for nuclear DNA, had higher genetic diversities and lower levels of relatedness at swarming (mating) sites than in maternity (breeding) colonies, and showed more differentiation between colonies than between swarming sites. All these suggest that populations are shaped by strong female philopatry, male dispersal, and outbreeding throughout their European range. We conclude that Bechstein's bats have a stable social system that is independent from the postglacial history and location of the populations. Our findings have implications for the understanding of the benefits of sociality in female Bechstein's bats and for the conservation of this endangered species.     

Heavy metal tolerance and accumulation in metallicolous and non-metallicolous populations of Thlaspi caerulescens from continental Europe

In continental Europe, the heavy metal hyperaccumulator Thlaspi caerulescens occurs both on heavy-metal polluted soils (subsp. calaminare) and on soils with normal heavy metal content (subsp. caerulescens). In order to assess the extent and partitioning of variation in heavy metal tolerance and foliar mineral composition, twelve families from two populations of each subspecies were grown in pots in four soil treatments differing in heavy metal (Zn, Pb) and macronutrient concentrations. The two subspecies differed systematically in many respects. Subsp. calaminare had a higher survival at high levels of heavy metals and a higher tolerance index in all treatments. It also had three times lower foliar zinc and lead concentrations when grown at moderate levels of heavy metals. This, together with a negative correlation of foliar Pb concentration with growth in subsp. caerulescens, suggests that heavy metal accumulation per se is not a mechanism of tolerance in this species. Variation among families within populations accounted for a larger proportion of total variance in growth and mineral composition than variation between populations. Additionally, within population variation in heavy metal tolerance and accumulation was significantly lower in subsp. calaminare. This suggests that, adding to a background constitutive tolerance at the species level, natural selection has increased heavy metal tolerance in metallicolous populations of Thlaspi caerulescens.     

DNA diversity of human populations from Eastern Europe and Siberia studied by multilocus DNA fingerprinting

We used DNA fingerprinting with M13 phage DNA as a probe to estimate the degree of genomic variability and genetic relationships in a heterogeneous group of 13 populations from Eastern Europe and Siberia. The popultaions belong to three language families: Indo-European (Slavonic: Russians, Byelorussians), Uralic (Finno-Ugric: Maris, Mordvinians, Udmurts), and Altaic (Turkic: Bashkirs, Tatars, Chuvashes, Yakuts). Multivariate statistical analyses were used (multidimensional scaling, cluster, and multiple correspondence analyses), and coefficients of gene differentiation (Gst) were evaluated. The level of interpopulation subdivision in the various ethnic groups appeared to be different: the Byelorussian populations revealed no regional differences, in contrast to the Bashkir populations, which formed a heterogeneous group. The populations subdivided into three general clusters: Slavonic populations formed a separate tight cluster characterized by a minimal level of interpopulation diversity, Bashkir and Yakut populations formed the second cluster, and the Finno-Ugric and several populations of the Turkic linguistic groups formed the third cluster. The robustness of these results obtained by different statistical data treatments reveals that multilocus DNA fingerprinting can be reliably used for population studies.Communicated by G. P. Georgiev     

Genetic structure and history of populations of the deep-sea fish Helicolenus dactylopterus (Delaroche, 1809) inferred from mtDNA sequence analysis

Helicolenus dactylopterus is an Atlantic benthopelagic fish species inhabiting high-energy habitats on continental slopes, seamounts and islands. Partial sequences of the mitochondrial control region (D-loop) and cytochrome b (cyt b) were used to test the hypothesis that H. dactylopterus disperses between continental margin, island and seamount habitats on intraregional, regional and oceanic scales in the North Atlantic. Individuals were collected from five different geographical areas: Azores, Madeira, Portugal (Peniche), Cape Verde and the northwest Atlantic. D-loop (415 bp) and cyt b (423 bp) regions were partially sequenced for 208 and 212 individuals, respectively. Analysis of variation among mitochondrial DNA sequences based on pairwise F-statistics and AMOVA demonstrated marked genetic differentiation between populations in different geographical regions specifically the Mid-Atlantic Ridge (Azores)/northeast Atlantic (Portugal, Madeira) compared to populations around the Cape Verde Islands and in the northwest Atlantic. Some evidence of intraregional genetic differentiation between populations was found. Minimum-spanning network analysis revealed star-shaped patterns suggesting that populations had undergone expansion following bottlenecks and/or they have been colonized by jump dispersal events across large geographical distances along pathways of major ocean currents. Mismatch distribution analysis indicated that Azores and northwest Atlantic populations fitted a model of historical population expansion following a bottleneck/founder event estimated to be between 0.64 and 1.2 million years ago (Ma).