Browsing by Author "Diekmann, O. E."
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- Connectivity, neutral theories and the assessment of species vulnerability to global change in temperate estuariesPublication . Chust, G.; Albaina, A.; Aranburu, A.; Borja, A.; Diekmann, O. E.; Estonba, A.; Franco, J.; Garmendia, J. M.; Iriondo, M.; Muxika, I.; Rendo, F.; Rodriguez, Juan; Ruiz-Larrañaga, O.; Serrão, Ester; Valle, M.One of the main adaptation strategies to global change scenarios, aiming to preserve ecosystem functioning and biodiversity, is to maximize ecosystem resilience. The resilience of a species metapopulation can be improved by facilitating connectivity between local populations, which will prevent demographic stochasticity and inbreeding. This investigation estimated the degree of connectivity among estuarine species along the north-eastern Iberian coast, in order to assess community vulnerability to global change scenarios. To address this objective, two connectivity proxy types have been used based upon genetic and ecological drift processes: 1) DNA markers for the bivalve cockle (Cerastoderma edule) and seagrass Zostera noltei, and 2) the decrease in the number of species shared between two sites with geographic distance. Neutral biodiversity theory predicts that dispersal limitation modulates this decrease, and this has been explored in estuarine plants and macroinvertebrates. Results indicate dispersal limitation for both saltmarsh plants and seagrass beds community and Z. noltei populations; this suggests they are especially vulnerable to expected climate changes on their habitats. In contrast, unstructured spatial pattern found in macroinvertebrate communities and in C. edule genetic populations in the area suggests that estuarine soft-bottom macroinvertebrates with planktonic larval dispersal strategies may have a high resilience capacity to moderate changes within their habitats. Our findings allow environmental managers to prioritize the most vulnerable species and habitats to be restored.
- Development and characterization of highly polymorphic microsatellite loci for the Western Spadefoot toad, Pelobates cultripesPublication . Van De Vliet, M. S.; Diekmann, O. E.; Serrão, Ester; Beja, PedroNine highly polymorphic microsatellite markers were isolated and characterized for the Western Spadefoot, Pelobates cultripes. Remarkably, for this amphibian species high numbers of microsatellites were found as part of larger repeat containing regions, making primer design difficult. For nine loci, primers were designed successfully and genotyping of individuals was reliable and consistent. Number of alleles and heterozygosity for these loci ranged from 9 to 34 and from 0.72 to 0.94, respectively. The high levels of polymorphism revealed by our developed loci should provide insight into population genetic structure and levels of dispersal for this typical Mediterranean temporary pond-breeding amphibian.
- Genetic evidence for polygynandry in the black-striped pipefish Syngnathus abaster: A microsatellite-based parentage analysisPublication . Hübner, K.; Gonzalez-Wanguemert, Mercedes; Diekmann, O. E.; Serrão, EsterSexual selection theory predicts that, in organisms with reversed sex roles, more polyandrous species exhibit higher levels of sexual dimorphism. In the family Syngnathidae (pipefish, seahorses, and seadragons), males provide all parental care by carrying developing embryos on their ventral surfaces, and females develop secondary sex characters. Syngnathids exhibit a variety of genetic mating patterns, making them an ideal group to test predictions of sexual selection theory. Here, we describe the mating system of the black-striped pipefish Syngnathus abaster, using 4 highly variable microsatellites to analyze parentage of 102 embryos. Results revealed that 1) both sexes mate multiple times over the course of a pregnancy (polygynandrous mating system), 2) eggs are spatially segregated by maternity within each brood pouch, and 3) larger females have higher mating success (Kolmogorov–Smirnov test; P < 0.05). Together with similar studies of other syngnathid species, our results support the hypothesis that the mating system is related to the intensity of sexual dimorphism.
- Genetic evidence for polygynandry in the black-striped pipefish syngnathus abaster: a microsatellite-based parentage analysisPublication . Huebner, Kerstin; Gonzalez-Wanguemert, Mercedes; Diekmann, O. E.; Serrão, EsterSexual selection theory predicts that, in organisms with reversed sex roles, more polyandrous species exhibit higher levels of sexual dimorphism. In the family Syngnathidae (pipefish, seahorses, and seadragons), males provide all parental care by carrying developing embryos on their ventral surfaces, and females develop secondary sex characters. Syngnathids exhibit a variety of genetic mating patterns, making them an ideal group to test predictions of sexual selection theory. Here, we describe the mating system of the black-striped pipefish Syngnathus abaster, using 4 highly variable microsatellites to analyze parentage of 102 embryos. Results revealed that 1) both sexes mate multiple times over the course of a pregnancy (polygynandrous mating system), 2) eggs are spatially segregated by maternity within each brood pouch, and 3) larger females have higher mating success (Kolmogorov–Smirnov test; P < 0.05). Together with similar studies of other syngnathid species, our results support the hypothesis that the mating system is related to the intensity of sexual dimorphism.
- Highly polymorphic microsatellite loci for the Parsley frog (Pelodytes punctatus): characterization and testing for cross-species amplificationPublication . Van De Vliet, M. S.; Diekmann, O. E.; Serrão, Ester; Beja, PedroA microsatellite library was developed using genomic DNA of the Parsley frog, Pelodytes punctatus, an amphibian species which inhabits Mediterranean temporary pond systems. Number of alleles and heterozygosity ranged from 10 to 25 and from 0.66 to 0.90, respectively. Crossspecies amplification was successful for 13 of the 15 developed loci for the related species, Pelodytes ibericus. The high levels of polymorphism revealed by these loci will be extremely useful for characterizing the population genetic diversity and structure and to estimate levels of dispersal and gene flow in the species P. punctatus and P. ibericus.
- Highly polymorphic microsatellite markers for the short-snouted seahorse (hippocampus hippocampus), including markers from a closely related species the long-snouted seahorse (hippocampus guttulatus)Publication . Van De Vliet, M. S.; Diekmann, O. E.; Serrão, EsterSpecies of the family Syngnathidae are increasingly being investigated for conservation purposes but also for mating system and genetic parentage studies. The availability of highly polymorphic markers will be of great importance to conduct these kinds of studies. This paper describes the development and characterization of 10 polymorphic microsatellite markers for Hippocampus hippocampus and the utility of nine markers which were developed for a closely related species Hippocampus guttulatus. The number of alleles per locus developed for H. hippocampus ranged from 14 to 30, with levels of heterozygosity between 0.90 and 0.95. Most of the markers were successfully cross-amplified in the sister species, giving clear and unambiguous peaks and maintaining high levels of polymorphism.
- Isolation of highly polymorphic microsatellite loci for a species with a large genome size: Sharp-ribbed salamander (Pleurodeles waltl)Publication . Van De Vliet, M. S.; Diekmann, O. E.; Serrão, Ester; Beja, PedroFourteen highly polymorphic microsatellite markers were developed and characterized for the sharp-ribbed salamander, Pleurodeles waltl. Isolating microsatellites with more than 12 single repeat type units was only successful for a tetranucleotide repeat (ATAG). Compared to microsatellite libraries constructed simultaneously for two anuran amphibian species, a greater number of primer pairs designed for P. waltl had to be discarded, due to consistent amplification problems. Low amplification success rate for P. waltl may be due to its larger genome size. Consequently, to avoid nonspecific binding and to increase amplification success, polymerase chain reaction programmes with touchdown cycles were used. For 14 microsatellite markers, amplification was successful and consistent with number of alleles and expected heterozygosity ranging from seven to 22 and from 0.79 to 0.94, respectively. All 14 microsatellite markers will be extremely useful for metapopulation studies of this unique amphibian species.
- Permanent genetic resources added to molecular ecology resources database 1 May 2009-31 July 2009Publication . Almany, G. R.; De Arruda, M. P.; Arthofer, W.; Atallah, Z. K.; Beissinger, S. R.; Berumen, M. L.; Bogdanowicz, S. M.; Brown, S. D.; Bruford, M. W.; Burdine, C.; Busch, J. W.; Campbell, N. R.; Carey, D.; Carstens, B. C.; Chu, K. H.; Cubeta, M. A.; Cuda, J. P.; Cui, Z.; Datnoff, L. E.; D'Ávila, J. A.; Davis, E. S.; Davis, R. M.; Diekmann, O. E.; Eizirik, E.; Fargallo, J. A.; Fernandes, F.; Fukuda, H.; Gale, L. R.; Gallagher, E.; Gao, Y.; Girard, P.; Godhe, A.; Gonçalves, E. C.; Gouveia, Licínia; Grajczyk, A. M.; Grose, M. J.; Gu, Z.; Halldén, C.; Härnström, K.; Hemmingsen, A. H.; Serrão, EsterThis article documents the addition of 512 microsatellite marker loci and nine pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Alcippe morrisonia morrisonia, Bashania fangiana, Bashania fargesii, Chaetodon vagabundus, Colletes floralis, Coluber constrictor flaviventris, Coptotermes gestroi, Crotophaga major, Cyprinella lutrensis, Danaus plexippus, Fagus grandifolia, Falco tinnunculus, Fletcherimyia fletcheri, Hydrilla verticillata, Laterallus jamaicensis coturniculus, Leavenworthia alabamica, Marmosops incanus, Miichthys miiuy, Nasua nasua, Noturus exilis, Odontesthes bonariensis, Quadrula fragosa, Pinctada maxima, Pseudaletia separata, Pseudoperonospora cubensis, Podocarpus elatus, Portunus trituberculatus, Rhagoletis cerasi, Rhinella schneideri, Sarracenia alata, Skeletonema marinoi, Sminthurus viridis, Syngnathus abaster, Uroteuthis (Photololigo) chinensis, Verticillium dahliae, Wasmannia auropunctata, and Zygochlamys patagonica. These loci were cross-tested on the following species: Chaetodon baronessa, Falco columbarius, Falco eleonorae, Falco naumanni, Falco peregrinus, Falco subbuteo, Didelphis aurita, Gracilinanus microtarsus, Marmosops paulensis, Monodelphis Americana, Odontesthes hatcheri, Podocarpus grayi, Podocarpus lawrencei, Podocarpus smithii, Portunus pelagicus, Syngnathus acus, Syngnathus typhle,Uroteuthis (Photololigo) edulis, Uroteuthis (Photololigo) duvauceli and Verticillium albo-atrum. This article also documents the addition of nine sequencing primer pairs and sixteen allele specific primers or probes for Oncorhynchus mykiss and Oncorhynchus tshawytscha; these primers and assays were cross-tested in both species.
- Population genetics of dwarf eelgrass Zostera noltii throughout its biogeographic rangePublication . Coyer, J. A.; Diekmann, O. E.; Serrão, Ester; Procaccini, G.; Milchakova, N.; Pearson, G. A.; Stam, W. T.; Olsen, J. L.The marine angiosperm Zostera noltii (dwarf eelgrass), an important facilitator species and food source for invertebrates and waterfowl, predominantly inhabits intertidal habitats along eastern Atlantic shores from Mauritania to southern Norway/Kattegat Sea and throughout the Mediterranean, Black and Azov seas. We used 9 microsatellite loci to characterize population structure at a variety of spatial scales among 33 populations from 11 localities throughout the entire biogeographic range. Isolation by distance analysis suggested a panmictic genetic neighborhood of 100 to 150 km. At the global scale, a neighbor-joining tree based on Reynolds distances revealed strongly-supported groups corresponding to northern Europe, Mauritania and the Black/Azov Sea; separate Mediterranean and Atlantic-Iberian groups were poorly supported. Clones (genets with multiple ramets) were present in most populations but were generally small (ca. <3 m2). Exceptions were found in Mauritania (ca. 29 m in length), the Azov Sea (ca. 40 m in length) and the Black Sea (ca. 50 m in length). Although genetic diversity and allelic richness generally decreased from Mauritania to Denmark, the putative post-glacial recolonization route, both were unexpectedly high among populations from the German Wadden Sea.
- Population genetics of Zostera noltii along the west Iberian coast: Consequences of small population size, habitat discontinuity and near-shore currentsPublication . Diekmann, O. E.; Coyer, J. A.; Ferreira, J.; Olsen, J. L.; Stam, W. T.; Pearson, G. A.; Serrão, EsterThe effects of oceanographic patterns on marine genetic biodiversity along the SW Iberian Peninsula are poorly understood. We addressed the question of whether gene flow in this region depends solely on geographic distance between isolated patches of suitable habitat or if there are superimposed effects correlated with other factors such as current patterns. Zostera noltii, the dwarf eelgrass, is the keystone habitat-structuring seagrass species on intertidal mudflats along the Iberian west coast. We used 9 microsatellite loci to analyze population genetic diversity and differentiation for all existing 8 populations from NW Spain (Ria de Vigo) to SW Spain (Puerto Real, Cadiz). Populations are highly genetically differentiated as shown by high significant FST,Wright’s fixation index, (0.08 to 0.26) values. A neighbor-joining tree based on Reynold’s distances computed from allele frequencies revealed a split between northern and southern populations (bootstrap support of 84%). This pattern of differentiation can be explained by (1) ocean surface current patterns present during Z. noltii’s reproductive season which cause a dispersal barrier between the northern and southern populations of this region, (2) habitat isolation, due to large geographic distances between suitable habitats, preventing frequent gene flow, and (3) small effective population sizes, causing high drift and thus faster differentiation rates.