Mitochondrial DNA Data Research Articles

Phylogeography of a Morphologically Cryptic Golden Mole Assemblage from South-Eastern Africa.

The Greater Maputaland-Pondoland-Albany (GMPA) region of southern Africa was recently designated as a centre of vertebrate endemism. The phylogeography of the vertebrate taxa occupying this region may provide insights into the evolution of faunal endemism in south-eastern Africa. Here we investigate the phylogeographic patterns of an understudied small mammal species assemblage (Amblysomus) endemic to the GMPA, to test for cryptic diversity within the genus, and to better understand diversification across the region. We sampled specimens from 50 sites across the distributional range of Amblysomus, with emphasis on the widespread A. hottentotus, to analyse geographic patterns of genetic diversity using mitochondrial DNA (mtDNA) and nuclear intron data. Molecular dating was used to elucidate the evolutionary and phylogeographic history of Amblysomus. Our phylogenetic reconstructions show that A. hottentotus comprises several distinct lineages, or evolutionarily significant units (ESUs), some with restricted geographic ranges and thus worthy of conservation attention. Divergence of the major lineages dated to the early Pliocene, with later radiations in the GMPA during the late-Pliocene to early-Pleistocene. Evolutionary diversification within Amblysomus may have been driven by uplift of the Great Escarpment c. 5–3 million years ago (Ma), habitat changes associated with intensification of the east-west rainfall gradient across South Africa and the influence of subsequent global climatic cycles. These drivers possibly facilitated geographic spread of ancestral lineages, local adaptation and vicariant isolation. Our study adds to growing empirical evidence identifying East and southern Africa as cradles of vertebrate diversity.

Integrative insect taxonomy based on morphology, mitochondrial DNA, and hyperspectral reflectance profiling

Author(s): Wang, Y; Nansen, C; Zhang, Y | Abstract: Integrative taxonomy is considered a reliable taxonomic approach of closely related and cryptic species by integrating different sources of taxonomic data (genetic, ecological, and morphological characters). In order to infer the boundaries of seven species of the evacanthine leafhopper genus Bundera Distant, 1908 (Hemiptera: Cicadellidae), an integrated analysis based on morphology, mitochondrial DNA, and hyperspectral reflectance profiling (37 spectral bands from 411-870nm) was conducted. Despite their morphological similarities, the genetic distances of the cytochromec oxidase subunitI (COI) gene among the tested species are relatively large (5.8-17.3%). The species-specific divergence of five morphologically similar species (Bundera pellucida and Bunderaspp.1-4) was revealed in mitochondrial DNA data and reflectance profiling. A key to identifying males is provided, and their morphological characters are described. Average reflectance profiles from the dorsal side of specimens were classified based on linear discriminant analysis. Cross-validation of reflectance-based classification revealed that the seven species could be distinguished with 91.3% classification accuracy. This study verified the feasibility of using hyperspectral imaging data in insect classification, and our work provides a good example of using integrative taxonomy in studies of closely related and cryptic species.

Rise (and demise?) of subspecies in the Galah (Eolophus roseicapilla), a widespread and abundant Australian cockatoo

The Galah (Eolophus roseicapilla) is a widespread Australian bird. Its geographical variation and subspecies remain poorly understood. We sampled 192 specimens from across the entire range of the species to assess its phylogeographical structure using the mitochondrially encoded NADH dehydrogenase 2 (MT-ND2) gene. A subset of specimens was examined for nuclear DNA diversity using the Amplified Fragment Length Polymorphism (AFLP) method. Weakly defined structure was evident in the mitochondrial DNA (mtDNA) data, which suggested three geographically defined haplogroups that broadly coincide with the three conventionally recognised subspecies: E. r. roseicapilla—western haplogroup; E. r. albiceps—eastern haplogroup; and E. r. kuhli—northern haplogroup. The three haplogroups all overlap and intersect broadly across the centre of the Australian continent. Geographical expansions of each haplogroup appear to have occurred before and after the Last Glacial Maximum (~20 000 years ago), the species itself probably having undergone an earlier expansion at c. 60 000 years ago. The preliminary nuclear AFLP data suggest very little structure though they likely track more recent processes of gene flow and population admixture. Expansion of the species since European settlement represents another, later expansion uncoupled from what is tracked in the mtDNA data. Future quantitative analyses of phenotypic variation will enhance the precision of how geographical variation in all datasets in this species should be interpreted.

Fifteen into Three Does Go: Morphology, Genetics and Genitalia Confirm Taxonomic Inflation of New Zealand Beetles (Chrysomelidae: Eucolaspis)

Eucolaspis Sharp 1886 is a New Zealand native leaf beetle genus (Coleoptera: Chrysomelidae: Eumolpinae) with poorly described species and a complex taxonomy. Many economically important fruit crops are severely damaged by these beetles. Uncertain species taxonomy of Eucolaspis is leaving any biological research, as well as pest management, tenuous. We used morphometrics, mitochondrial DNA and male genitalia to study phylogenetic and geographic diversity of Eucolaspis in New Zealand. Freshly collected beetles from several locations across their distribution range, as well as identified voucher specimens from major museum collections were examined to test the current classification. We also considered phylogenetic relationships among New Zealand and global Eumolpinae (Coleoptera: Chyrosomelidae). We demonstrate that most of the morphological information used previously to define New Zealand Eucolaspis species is insufficient. At the same time, we show that a combination of morphological and genetic evidence supports the existence of just 3 mainland Eucolaspis lineages (putative species), and not 5 or 15, as previously reported. In addition, there may be another closely related lineage (putative species) on an offshore location (Three Kings Islands, NZ). The cladistic structure among the lineages, conferred through mitochondrial DNA data, was well supported by differences in male genitalia. We found that only a single species (lineage) infests fruit orchards in Hawke’s Bay region of New Zealand. Species-host plant associations vary among different regions.

Speciation processes in putative island endemic sister bat species: false impressions from mitochondrial DNA and microsatellite data.

Cases of geographically restricted co-occurring sister taxa are rare and may point to potential divergence with gene flow. The two bat species Murina gracilis and Murina recondita are both endemic to Taiwan and are putative sister species. To test for nonallopatric divergence and gene flow in these taxa, we generated sequences using Sanger and next-generation sequencing, and combined these with microsatellite data for coalescent-based analyses. MtDNA phylogenies supported the reciprocally monophyletic sister relationship between M. gracilis and M. recondita; however, clustering of microsatellite genotypes revealed several cases of species admixture suggesting possible introgression. Sequencing of microsatellite flanking regions revealed that admixture signatures stemmed from microsatellite allele homoplasy rather than recent introgressive hybridization, and also uncovered an unexpected sister relationship between M. recondita and the continental species Murina eleryi, to the exclusion of M. gracilis. To dissect the basis of these conflicts between ncDNA and mtDNA, we analysed sequences from 10 anonymous ncDNA loci with *beast and isolation-with-migration and found two distinct clades of M. eleryi, one of which was sister to M. recondita. We conclude that Taiwan was colonized by the ancestor of M. gracilis first, followed by the ancestor of M. recondita after a period of allopatric divergence. After colonization, the mitochondrial genome of M. recondita was replaced by that of the resident M. gracilis. This study illustrates how apparent signatures of sympatric divergence can arise from complex histories of allopatric divergence, colonization and hybridization, thus highlighting the need for rigorous analyses to distinguish between such scenarios.

Origin and introduction history of self-sustaining rainbow trout populations in Europe as inferred from mitochondrial DNA and a Y-linked marker

Following its introduction in the late nineteenth century, rainbow trout gradually spread to become one of the most widespread non-native fishes. Nevertheless, despite continuous introductions, they have become self-sustaining in only a limited number of European rivers, most of which are located in the Prealps. There is no consensus on the reasons for the absence of self-sustaining populations over most of Europe, though genetic differences have been suggested as a potential underlying factor. We conducted a population genetic study of the structure and origin of European populations to help resolve these questions. We examined variation in mitochondrial D-loop and the Y-linked marker of 41 self-sustaining, stocked, and hatchery populations from Europe and compared them to native and hatchery populations in North America. High levels of genetic diversity but little inter-population genetic variation suggests that European populations are derived from multiple sources, with a great majority of parental populations belonging to steelhead and coastal rainbow trout from Central and Northern California. Our study revealed no considerable genetic differences among European self-sustaining, stocked, and hatchery populations. The mitochondrial DNA data do not allow evaluation of selection and adaptive traits and thus cannot explain potential population differences arising in their naturalization success.

Historical demography of the Eurasian green woodpecker: integrating phylogeography and ecological niche modelling to test glacial refugia hypothesis

In this study, we re-evaluated historical demography of the Eurasian green woodpecker (Picus viridis) on the basis of previously published multi-locus mitochondrial DNA (mtDNA) data and ecological niche modelling. We particularly aimed to test glacial refugia hypothesis during climatic oscillations of the late Quaternary for the Eurasian green woodpecker. Our results indicate that the Eurasian green woodpecker was sensitive to the effects of climate change. Prior to the Last Glacial Maximum (22000 years ago), the population contraction started and the Eurasian green woodpecker restricted its range to southern Europe (including France), Anatolia, and the Caucasus/Caspian region, and, afterwards, substantially expanded its range from this restricted area to its present range around 14500 years before present. Therefore, during the Last Glacial Maximum, we recognize a single large refugium for this species, located in southern Europe (including France), Anatolia, and the Caucasus/Caspian region.

Identification and Distribution of Morphologically Conserved Smoothhound Sharks in the Northern Gulf of Mexico

AbstractIdentification of sharks within the genus Mustelus (smoothhound sharks) is problematic because of extensive overlap in external morphology among species. Consequently, species‐specific management of smoothhound shark resources is difficult when multiple species inhabit the same geographic region. The species identification and distribution of smoothhound sharks in the northern Gulf of Mexico (the Gulf) were assessed using sequences of mitochondrial DNA, nuclear‐encoded microsatellites, and catch data. Phylogenetic analysis of 1,047 base pairs of mitochondrially encoded ND‐2 sequences and Bayesian clustering of multilocus genotypes at 15 microsatellites revealed three genetically distinct monophyletic lineages (clades) of smoothhound sharks in the Gulf. Examination of external morphology revealed characters that distinguished each genetically distinct clade, and based on species descriptions and comparisons with the type and other specimens in established collections, the lineages were identified as Smooth Dogfish Mustelus canis, Florida Smoothhound Mustelus norrisi, and Gulf Smoothhound Mustelus sinusmexicanus. Two hundred and eighty‐seven smoothhound sharks sampled from across the Gulf were then assigned unequivocally, based on genetic data, to one of the three species. Multifactorial analysis and homogeneity tests of species‐specific means versus grand means of spatiotemporal factors (depth, longitude, and month) at capture indicated significant differences among the three species with respect to all three factors. On average, the Smooth Dogfish is found in deeper waters than the Gulf Smoothhound, whereas the Florida Smoothhound inhabits relatively shallow waters. A diagnostic key for the field identification of adult specimens of each species is provided.

Historical demography of bird populations from Hispaniola assessed by nuclear and mitochondrial gene sequences

Molecular markers can be used to infer the demographic history of a given species, but many historic processes simultaneously impact multiple species. Thus, comparative historical demography has the potential to provide insight into drivers of evolution. In this study, we used nuclear DNA (nDNA) sequences to corroborate (or refute) demographic inferences based on earlier mitochondrial DNA (mtDNA) data from 16 species of Hispaniola birds. Our previously published analysis suggested population expansion in five of six migratory species (following glacial retreat in North America), with less evidence of expansion in non-migratory species. Additional molecular markers should reduce locus-specific bias, and so we generated sequence data for several nuclear loci. Test statistics associated with the nDNA provided only equivocal evidence for population expansion in 10 of the 16 species. Discordance between mtDNA and nDNA is not uncommon because the two genomes are exposed to different selective pressures and have different effective population sizes and modes of inheritance. The nDNA analyses reported here cast some doubt on our earlier mtDNA inferences. They also suggest that the signal to noise ratio of demographic statistics is typically low because of the inherent variability in selective regimes and coalescence across loci.

Antiquity and diversity of aboriginal Australian Y-chromosomes.

Understanding the origins of Aboriginal Australians is crucial in reconstructing the evolution and spread of Homo sapiens as evidence suggests they represent the descendants of the earliest group to leave Africa. This study analyzed a large sample of Y-chromosomes to answer questions relating to the migration routes of their ancestors, the age of Y-haplogroups, date of colonization, as well as the extent of male-specific variation. Knowledge of Y-chromosome variation among Aboriginal Australians is extremely limited. This study examined Y-SNP and Y-STR variation among 657 self-declared Aboriginal males from locations across the continent. 17 Y-STR loci and 47 Y-SNPs spanning the Y-chromosome phylogeny were typed in total. The proportion of non-indigenous Y-chromosomes of assumed Eurasian origin was high, at 56%. Y lineages of indigenous Sahul origin belonged to haplogroups C-M130*(xM8,M38,M217,M347) (1%), C-M347 (19%), K-M526*(xM147,P308,P79,P261,P256,M231,M175,M45,P202) (12%), S-P308 (12%), and M-M186 (0.9%). Haplogroups C-M347, K-M526*, and S-P308 are Aboriginal Australian-specific. Dating of C-M347, K-M526*, and S-P308 indicates that all are at least 40,000 years old, confirming their long-term presence in Australia. Haplogroup C-M347 comprised at least three sub-haplogroups: C-DYS390.1del, C-M210, and the unresolved paragroup C-M347*(xDYS390.1del,M210). There was some geographic structure to the Y-haplogroup variation, but most haplogroups were present throughout Australia. The age of the Australian-specific Y-haplogroups suggests New Guineans and Aboriginal Australians have been isolated for over 30,000 years, supporting findings based on mitochondrial DNA data. Our data support the hypothesis of more than one route (via New Guinea) for males entering Sahul some 50,000 years ago and give no support for colonization events during the Holocene, from either India or elsewhere.

Evaluating the biological discontinuity hypothesis of Cis-Baikal Early versus Late Neolithic-Early Bronze Age populations using dental non-metric traits

The aim of this study is to assess dental non-metric trait frequencies of Middle Holocene hunter–gatherer populations from the western Lake Baikal region of Siberia, the Russian Federation, for evidence of population discontinuity. Mortuary practices, cranial morphology, and mitochondrial DNA data have led to the hypothesis of a discontinuity event between the Early Neolithic (EN; ∼7500–7025 cal BP) and Late Neolithic–Early Bronze Age (LN–EBA; ∼5500–3700 cal BP) populations. Dental non-metric traits are highly heritable and can be used to infer biological affinity between populations. Mean measure of divergence results find that dental non-metric trait frequencies vary between archaeological periods in statistical terms, but the extent of difference is minor. In the LN–EBA sample, several, but not all, trait frequencies shift towards the range characteristic of populations with Western European genetic admixture. Gene flow from a population to the south of the Baikal region is the most likely explanation for this shift, although the role of genetic drift and the impact of small sample sizes cannot be discounted. Two cemeteries along the Angara River on either side of the discontinuity event have the most similar dental non-metric trait patterns. The similarity of traits between the EN site of Lokomotiv and the LN component of the site of Ust'-Ida I could suggest population continuity or genetic admixture between groups in this area. Dental non-metric trait data are shown to be an informative avenue for assessing past population events, revealing trends not detected by other data types, and directing research into our reconstruction of the history of these groups away from the shores of Lake Baikal to along the Angara River.

Biogeographical role of the Kuroshio Current in the amphibious mudskipper Periophthalmus modestus indicated by mitochondrial DNA data.

Quaternary climatic cycles have influenced marine organisms’ spatial distribution and population dynamics. This study aimed to elucidate the evolutionary influences of contemporary and glacial physical barriers on the population structure, demography and colonization history of the mudskipper (Periophthalmus modestus) based on a mitochondrial gene segment (ND5) from 131 individual fish sampled in the northwestern Pacific Ocean. The current Kuroshio Current and the glacial exposure of the Taiwan Strait appeared to have restricted migration among the South China Sea, coastal East China and Japan. However, genetic homogeneity (Nm>1) also suggested contemporary larval transportation by sea circulation between the East China Sea and the South China Sea or historical dispersal along the glacial exposed shoreline among China, Japan and the Ryukyu Islands. Evolutionary signals of the strengthened East Asian Summer Monsoon in the mid-Pleistocene and regional difference in intertidal primary productions were indicated by a late-Pleistocene population expansion of P. modestus with a higher effective population size in the South China Sea than in the East China Sea. Furthermore, a potential colonization origin from the South China Sea was consistently inferred by different clues, including the populations’ coalescence times, the ancestral haplotype distribution, the number of private haplotypes and species/genetic diversity.

Origin, evolution and conservation of the honey bees from La Palma Island (Canary Islands): molecular and morphological data

Genetic studies have shown a significant hybridization of local populations of Apis mellifera in the Canary Islands, as a consequence of queen importation. Since La Palma Island was a probable exception to this hybridization rule, a local honey bee Conservation Project was developed. As a first step, the genetic characterization of the population was performed with the scope of generating fundamental knowledge to correctly manage honey bee genetic resources. In this sense, the origin of the Canarian honey bee is at issue, since diverse morphological and genetic studies have shown it to be either African or European. In our study, 499 colonies from La Palma were analyzed using mitochondrial DNA, microsatellites and wing geometric morphometric data. Hybridization from the C evolutionary lineage was observed mainly at mitochondrial level, but this hybridization was focused on a restricted area and hybrid colonies were detected for replacement. All genetic and geometric morphometric results showed the Canarian honey bee clustered with Western European M branch, specifically with A. m. iberiensis subspecies, far from African ones. We concluded that the present Canarian honey bee gene pool would have originated most likely from human introductions from Portugal dating back to the conquest of the islands in the sixteenth century, although an ancestral natural colonization from Iberia cannot be ruled out. Results also showed that Canarian honey bees are genetically differentiated from A. m. iberiensis, probably due to micro-evolutionary processes, such as founder effects, bottleneck and local adaptation. Therefore, we propose the classification of these local populations as a differentiated ecotype of A. m. iberiensis. This study highlights the idiosyncrasy of the Canarian honey bee and the need to protect it, as it is a population that extends considerably the genetic diversity of M branch.

Understanding the relationship between Alouatta ululata and Alouatta belzebul (Primates: Atelidae) based on cytogenetics and molecular phylogeny

Normal 0 21 The genus Alouatta Lacepede 1799 comprises a group of neotropical primates distributed from southern Mexico to northern Argentina. Ten species of Alouatta occur in Brazil, including Alouatta belzebul (Linnaeus, 1766) and A. ululata Elliot, 1912; this latter being considered a full species or a junior synonymous of A . belzebul . In order to clarify the relationship of A. ululata with A. belzebul and inferring their relationships with other Alouatta species, karyotyping and mitochondrial DNA data were analyzed. Phylogenetic analyses were carried out with a 801 pb fragment of cytochrome b DNA of one specimen of A . ululata and 33 sequences of A. belzebul, A. caraya, A. fusca, A. nigerrima, A. seniculus, A. macconnelli available in GenBank, with Brachyteles arachnoides as outgroup. The G-band k aryotype of a male A. ululata showed a diploid number of 49, similar to the one reported for A. belzebul, with the same pattern of autosome heteromorphism, apparently resulting from a Y-autosome translocation. Maximum-likelihood and Bayesian analysis and median joining network did not show an internal structure within A. belzebul and placed A. ululata haplotype within the A. belzebul clade. K aryotypic and m olecular analyses herein carried out corroborate did not allow the separation of A. ululata from A. belzebul .

How Well Do Molecular and Pedigree Relatedness Correspond, in Populations with Diverse Mating Systems, and Various Types and Quantities of Molecular and Demographic Data?

Kinship analyses are important pillars of ecological and conservation genetic studies with potentially far-reaching implications. There is a need for power analyses that address a range of possible relationships. Nevertheless, such analyses are rarely applied, and studies that use genetic-data-based-kinship inference often ignore the influence of intrinsic population characteristics. We investigated 11 questions regarding the correct classification rate of dyads to relatedness categories (relatedness category assignments; RCA) using an individual-based model with realistic life history parameters. We investigated the effects of the number of genetic markers; marker type (microsatellite, single nucleotide polymorphism SNP, or both); minor allele frequency; typing error; mating system; and the number of overlapping generations under different demographic conditions. We found that (i) an increasing number of genetic markers increased the correct classification rate of the RCA so that up to >80% first cousins can be correctly assigned; (ii) the minimum number of genetic markers required for assignments with 80 and 95% correct classifications differed between relatedness categories, mating systems, and the number of overlapping generations; (iii) the correct classification rate was improved by adding additional relatedness categories and age and mitochondrial DNA data; and (iv) a combination of microsatellite and single-nucleotide polymorphism data increased the correct classification rate if <800 SNP loci were available. This study shows how intrinsic population characteristics, such as mating system and the number of overlapping generations, life history traits, and genetic marker characteristics, can influence the correct classification rate of an RCA study. Therefore, species-specific power analyses are essential for empirical studies.

Structure of the Black Bean AphidAphis fabae(Hemiptera: Aphididae) Complex, Inferred from DNA Barcoding

The black bean aphid, Aphis fabae Scopoli is a polyphagous aphid causing significant damage to several cultivated and uncultivated plants. In the present work, we have used COI barcoding to distinguish between three subspecies of A. fabae, frequently found in Tunisia, namely A. f. fabae, A. f. solanella and A. f. cirsiiacanthoidis. Results of our study revealed that COI barcoding was efficient to generate haplotypes discriminating A. f. fabae from the two remaining subspecies. Indeed, among seven haplotypes, identified and named H1–H7, five were found exclusively in A. f. fabae, one represented exclusively A. f. cirsiiacanthoidis, and one was shared by A. f. cirsiiacanthoidis and A. f. solanella. However, the differentiation of Aphis f. fabae from A. f. solanella and A. f. cirsiiacanthoidis was not further supported by a phylogenetic distinction, as it was revealed by neighbour-joining and maximum parsimony phylogenies. Such a coherent genetic structure of the A. fabae complex, not governed by the subspecies factor, as inferred from our present mitochondrial (mt)DNA data, is in agreement with previous analyses based on genomic DNA. Therefore, we hypothesize that the phenotypical and physiological processes having led to differentiation between subspecies would have arisen from weak selection pressures, thus resulting in little genetic change between subspecies. In combination with additional still-to-come data from additional markers, results of this study will be important to constitute a groundwork for pest integrated management.

Inferring the links between breeding and wintering grounds in a Palearctic– African migratory bird, the Great Reed Warbler, using mitochondrial DNA data

Understanding spatial connections between breeding and wintering populations is critical for developing sound conservation plans in migratory animals. However, for long-distance migratory songbird species wintering in sub-Saharan Africa, many of which are in a state of population decline, information on migratory connectivity is especially lacking. We used mitochondrial DNA data from wintering populations of the Great Reed Warbler (Acrocephalus arundinaceus) in western (Nigeria), southern (Botswana and Zambia) and eastern (Kenya) Africa, as well as from several Eurasian breeding populations, to compare genetic differentiation and haplotype sharing between non-breeding and breeding populations. We found that the population in Nigeria had the best genetic match to breeding populations in West and Central Europe. In contrast, Botswana matched with West, Central and East Europe, and Zambia with Central and East Europe and the Middle East. Finally, Kenya showed the most distinct connectivity pattern of the four analysed populations and matched with East Europe and, in particular, to the Middle East. Our results indicate clear but weak migratory connectivity in Great Reed Warblers, a pattern that should be considered in conservation strategies of Palearctic–African migratory passerines.

Multilocus Bayesian Estimates of Intra-Oceanic Genetic Differentiation, Connectivity, and Admixture in Atlantic Swordfish (Xiphias gladius L.).

Previous genetic studies of Atlantic swordfish (Xiphias gladius L.) revealed significant differentiation among Mediterranean, North Atlantic and South Atlantic populations using both mitochondrial and nuclear DNA data. However, limitations in geographic sampling coverage, and the use of single loci, precluded an accurate placement of boundaries and of estimates of admixture. In this study, we present multilocus analyses of 26 single nucleotide polymorphisms (SNPs) within 10 nuclear genes to estimate population differentiation and admixture based on the characterization of 774 individuals representing North Atlantic, South Atlantic, and Mediterranean swordfish populations. Pairwise F ST values, AMOVA, PCoA, and Bayesian individual assignments support the differentiation of swordfish inhabiting these three basins, but not the current placement of the boundaries that separate them. Specifically, the range of the South Atlantic population extends beyond 5°N management boundary to 20°N-25°N from 45°W. Likewise the Mediterranean population extends beyond the current management boundary at the Strait of Gibraltar to approximately 10°W. Further, admixture zones, characterized by asymmetric contributions of adjacent populations within samples, are confined to the Northeast Atlantic. While South Atlantic and Mediterranean migrants were identified within these Northeast Atlantic admixture zones no North Atlantic migrants were identified respectively in these two neighboring basins. Owing to both, the characterization of larger number of loci and a more ample spatial sampling coverage, it was possible to provide a finer resolution of the boundaries separating Atlantic swordfish populations than previous studies. Finally, the patterns of population structure and admixture are discussed in the light of the reproductive biology, the known patterns of dispersal, and oceanographic features that may act as barriers to gene flow to Atlantic swordfish.

Comparison of the genetic variation of captive ring-tailed lemurs with a wild population in Madagascar.

Genetic variability among captive and wild ring-tailed lemurs (Lemur catta) was assessed using mitochondrial and nuclear DNA data. A 529 bp segment of mtDNA was sequenced and 9 microsatellite loci were genotyped for 286 ring-tailed lemurs. Samples were obtained from the well-studied L. catta population at the Bezà Mahafaly Special Reserve and from captive animals at six institutions worldwide. We found evidence of possible patrilineal contribution but the absence of matrilineal contribution from the Bezà area, and haplotypes not found in Bezà but present in Ambohimahavelona, Andringitra Massif, and other unknown locations, in the sampled captive population, indicating that the founders of the captive population originated from a wide geographic range. Total genetic variation and relatedness in captive L. catta in the six institutions were similar in extent to that of the wild population in Bezà. Based on the diverse origins of the captive population founders our results suggest the erosion of genetic diversity in the captive population. Sampled individuals from the same institution were more closely related to each other than members of a social group in the wild. Individuals housed at different institutions were less closely related than those of different social groups at Bezà, indicating lower genetic exchange between captive institutions than between social groups in a locality in the wild. Our findings underscore the usefulness of genotyping in determining the geographic origin of captive population founders, obtaining pedigree information if paternity is uncertain, and in maximizing preservation of extant genetic diversity in captivity.

Past and present drivers of population structure in a small coastal fish, the European long snouted seahorse Hippocampus guttulatus

The effective design of species conservation programs is reliant on information such as extant geographic distribution, taxon-specific life-history characteristics, and the relative influence of historic processes and contemporary environmental parameters in shaping population genetic diversity. Seahorses are weak swimmers and have a brooded young, limiting their dispersal potential. They live in sheltered locations, which are physically isolated from each other. Therefore panmixia across their geographic range is unlikely. Hippocampus guttulatus, a seahorse inhabiting European waters, has a geographic range spanning a number of contemporary oceanographic features that are proposed barriers to gene flow. Thus this fish is well-placed to test the contributions of environment and life-history factors in shaping population structuring. This study found that mitochondrial DNA and nuclear DNA (microsatellite) genotype data are concordant in suggesting that, like many other small fishes in European waters, H. guttulatus extant populations expanded from at least one southern European refugial population. Subsequent population differentiation of four geographic lineages reflects contemporary oceanographic barriers to gene flow. Demographic analyses suggest a northward, and long-term isolation between Black Sea and Mediterranean Sea populations. Moreover H. guttulatus contemporary population distribution and population structure are predominately explained by historic and oceanographic influences. These findings suggest that conservation of genetic diversity in H. guttulatus may be aided by a network of marine protected areas (MPAs), implemented to conserve coastal habitats, but the species’ unusual life history and gamete retaining behaviours should be considered as part of management decisions including MPA design and fisheries management plans.