scholarly journals Dispersal and Differentiation of Deep-Sea Mussels of the GenusBathymodiolus(Mytilidae, Bathymodiolinae)

2009 ◽  
Vol 2009 ◽  
pp. 1-15 ◽  
Author(s):  
Akiko Kyuno ◽  
Mifue Shintaku ◽  
Yuko Fujita ◽  
Hiroto Matsumoto ◽  
Motoo Utsumi ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Shallow Water ◽  
Deep Sea ◽  
Dispersal Ability ◽  
Evolutionary Transition ◽  
Significant Genetic Differentiation ◽  
Evolutionary Processes ◽  
High Dispersal ◽  
High Gene

We sequenced the mitochondrial ND4 gene to elucidate the evolutionary processes ofBathymodiolusmussels and mytilid relatives. Mussels of the subfamily Bathymodiolinae from vents and seeps belonged to 3 groups and mytilid relatives from sunken wood and whale carcasses assumed the outgroup positions to bathymodioline mussels. Shallow water mytilid mussels were positioned more distantly relative to the vent/seep mussels, indicating an evolutionary transition from shallow to deep sea via sunken wood and whale carcasses.Bathymodiolus platifronsis distributed in the seeps and vents, which are approximately 1500 km away. There was no significant genetic differentiation between the populations. There existed high gene flow betweenB. septemdierumandB. breviorand low but not negligible gene flow betweenB. marisindicusandB. septemdierumorB. brevior, although their habitats are 5000–10 000 km away. These indicate a high adaptability to the abyssal environments and a high dispersal ability ofBathymodiolusmussels.

scholarly journals Serial founder effects and genetic differentiation during worldwide range expansion of monarch butterflies

2014 ◽  
Vol 281 (1797) ◽  
pp. 20142230 ◽  
Author(s):  
Amanda A. Pierce ◽  
Myron P. Zalucki ◽  
Marie Bangura ◽  
Milan Udawatta ◽  
Marcus R. Kronforst ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Genetic Drift ◽  
North American ◽  
Range Expansion ◽  
Dispersal Ability ◽  
Founder Effects ◽  
Long Distance ◽  
Mobile Species ◽  
High Dispersal

Range expansions can result in founder effects, increasing genetic differentiation between expanding populations and reducing genetic diversity along the expansion front. However, few studies have addressed these effects in long-distance migratory species, for which high dispersal ability might counter the effects of genetic drift. Monarchs ( Danaus plexippus ) are best known for undertaking a long-distance annual migration in North America, but have also dispersed around the world to form populations that do not migrate or travel only short distances. Here, we used microsatellite markers to assess genetic differentiation among 18 monarch populations and to determine worldwide colonization routes. Our results indicate that North American monarch populations connected by land show limited differentiation, probably because of the monarch's ability to migrate long distances. Conversely, we found high genetic differentiation between populations separated by large bodies of water. Moreover, we show evidence for serial founder effects across the Pacific, suggesting stepwise dispersal from a North American origin. These findings demonstrate that genetic drift played a major role in shaping allele frequencies and created genetic differentiation among newly formed populations. Thus, range expansion can give rise to genetic differentiation and declines in genetic diversity, even in highly mobile species.

scholarly journals Genetic differentiation in spite of high gene flow in the dominant rainforest tree of southeastern Australia, Nothofagus cunninghamii

Heredity ◽  
2015 ◽  
Vol 116 (1) ◽  
pp. 99-106 ◽  
Author(s):  
C J Duncan ◽  
J R P Worth ◽  
G J Jordan ◽  
R C Jones ◽  
R E Vaillancourt
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Southeastern Australia ◽  
High Gene Flow ◽  
High Gene

scholarly journals Gender-based Genetic Variability of Ailanthus excelsa Roxb, Populations Using, RAPD, ISSR and SCoT Markers

2020 ◽  
pp. 75-83
Author(s):  
Shabnam Bano ◽  
Sumaiya Ansari ◽  
Meena Choudhary ◽  
U. K. Tomar
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Gene Diversity ◽  
Dna Amplification ◽  
Ailanthus Excelsa ◽  
High Gene Flow ◽  
Diversity Assessment ◽  
High Gene ◽  
Gender Based

Ailanthus excelsa Roxb. is an economically important and multipurpose dioecious tree species of India, mainly used for fodder and timber. Gender-based genetic diversity of five populations of two sites (Jodhpur, Rajasthan and Deesa, Gujarat) of A. excelsa was assessed. A total of 42 RAPD, 20 ISSR and 23 SCoT primers were screened for DNA amplification of 232 individuals. Out of which only 25 primers (13 RAPD, 6 ISSR and 6 SCoT) were found polymorphic. The SCoT markers were showed the highest value for PIC, MI, Rp value, Nei’s gene diversity and Shannon’s index, as compared with the other two markers. Female individuals in all five populations had slightly higher genetic diversity as compared with male individuals. A high level of genetic diversity (55%) was detected within the populations of male and female individuals. High gene flow (6.70) and low genetic differentiation (0.069) values were found between Jodhpur and Deesa sites. Principal component analysis for all populations were accounted for 48.7% of the genetic variation. The Mantel test showed significant correlation (R = 0.178, P = .01) between genetic and geographic distances. The present study showed that SCoT markers were best for genetic diversity assessment in A. excelsa over RAPD and ISSR markers. High gene flow and low genetic differentiation in A. excelsa indicates its poor population fragmentation despite long geographic distances.

scholarly journals The Effect of Host’s Dispersal Ability on Fine-Scale Spatial Differentiation

2015 ◽  
Vol 1 (1) ◽  
pp. 38
Author(s):  
Julie Y. Xu
Keyword(s):  
Gene Flow ◽  
Spatial Variation ◽  
Spatial Differentiation ◽  
Freshwater Snail ◽  
Experimental Manipulation ◽  
Dispersal Ability ◽  
Fine Scale ◽  
Close Proximity ◽  
Southern Site ◽  
High Gene

Gene flow of a parasite is commonly contingent upon its most motile host’s dispersal rate. High gene flow can reduce local differentiation and potentially the rate of adaptation to local hosts (Blasco-Costa, Waters, & Poulin, 2011; Louhi, Karvonen, Rellstab, & Jokela, 2010). We investigated fine-scale spatial differentiation in a parasitic trematode (Microphallus sp.), which alternates between two hosts: a relatively sedentary invertebrate, a freshwater snail (Potamopyrgus antipodarum), and a highly motile vertebrate, a duck (Hechinger, 2012). In 2014, adult snails were sampled from 13 different sites around a New Zealand lake to determine the distribution of infection. Juvenile snails were also collected from these sites for experimental manipulation. Finally, parasite eggs were collected by sampling duck feces from a northern and southern site on the lake. Juvenile snails from each site were exposed to parasites from either the northern or southern source. The infection status of field-collected adults and experimental juveniles was determined by dissection. Given the close proximity between sites and the duck host’s strong dispersal ability, we predicted low spatial variation in infectivity of the two parasite sources. The results, however, indicate significant spatial variation in both host resistance and parasite infectivity. Though infection rates across host sites were significantly correlated, the two sources differed significantly in their infectivity to hosts from different sites. This result suggests that the two parasite sources are adapted to infect different hosts, indicating genetic differentiation of the parasite. In addition, the frequency of infection and resistance of the freshwater snail differed significantly between sites within close proximity to one another. Detection of strong variation indicates that dispersal of the vertebrate host does not prevent fine-scale spatial differentiation in this host-parasite system. Further studies are needed to investigate the forces that maintain the extensive spatial variation in disease observed. 

scholarly journals Testing the depth-differentiation hypothesis in a deepwater octocoral

2015 ◽  
Vol 282 (1807) ◽  
pp. 20150008 ◽  
Author(s):  
Andrea M. Quattrini ◽  
Iliana B. Baums ◽  
Timothy M. Shank ◽  
Cheryl L. Morrison ◽  
Erik E. Cordes
Keyword(s):  
Genetic Differentiation ◽  
Deep Sea ◽  
Water Mass ◽  
High Rate ◽  
Adaptive Divergence ◽  
Significant Genetic Differentiation ◽  
Closely Related Species ◽  
Species Formation ◽  
Geographical Distances ◽  
Isolation Mechanisms

The depth-differentiation hypothesis proposes that the bathyal region is a source of genetic diversity and an area where there is a high rate of species formation. Genetic differentiation should thus occur over relatively small vertical distances, particularly along the upper continental slope (200–1000 m) where oceanography varies greatly over small differences in depth. To test whether genetic differentiation within deepwater octocorals is greater over vertical rather than geographical distances, Callogorgia delta was targeted . This species commonly occurs throughout the northern Gulf of Mexico at depths ranging from 400 to 900 m. We found significant genetic differentiation ( F ST = 0.042) across seven sites spanning 400 km of distance and 400 m of depth. A pattern of isolation by depth emerged , but geographical distance between sites may further limit gene flow. Water mass boundaries may serve to isolate populations across depth; however, adaptive divergence with depth is also a possible scenario. Microsatellite markers also revealed significant genetic differentiation ( F ST = 0.434) between C. delta and a closely related species, Callogorgia americana , demonstrating the utility of microsatellites in species delimitation of octocorals. Results provided support for the depth-differentiation hypothesis, strengthening the notion that factors covarying with depth serve as isolation mechanisms in deep-sea populations.

scholarly journals Anthropogenic hybridization at sea: three evolutionary questions relevant to invasive species management

2020 ◽  
Vol 375 (1806) ◽  
pp. 20190547 ◽  
Author(s):  
Frédérique Viard ◽  
Cynthia Riginos ◽  
Nicolas Bierne
Keyword(s):  
Invasive Species ◽  
Gene Flow ◽  
Reproductive Isolation ◽  
Propagule Pressure ◽  
Dispersal Ability ◽  
Marine Animals ◽  
Contact Zones ◽  
High Fecundity ◽  
High Dispersal ◽  
Allopatric Divergence

Species introductions promote secondary contacts between taxa with long histories of allopatric divergence. Anthropogenic contact zones thus offer valuable contrasts to speciation studies in natural systems where past spatial isolations may have been brief or intermittent. Investigations of anthropogenic hybridization are rare for marine animals, which have high fecundity and high dispersal ability, characteristics that contrast to most terrestrial animals. Genomic studies indicate that gene flow can still occur after millions of years of divergence, as illustrated by invasive mussels and tunicates. In this context, we highlight three issues: (i) the effects of high propagule pressure and demographic asymmetries on introgression directionality, (ii) the role of hybridization in preventing introduced species spread, and (iii) the importance of postzygotic barriers in maintaining reproductive isolation. Anthropogenic contact zones offer evolutionary biologists unprecedented large scale hybridization experiments. In addition to breaking the highly effective reproductive isolating barrier of spatial segregation, they allow researchers to explore unusual demographic contexts with strong asymmetries. The outcomes are diverse, from introgression swamping to strong barriers to gene flow, and lead to local containment or widespread invasion. These outcomes should not be neglected in management policies of marine invasive species. This article is part of the theme issue ‘Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers’.

scholarly journals Mitochondrial DNA Suggests High Gene Flow in Ancient Murrelets

The Condor ◽  
2002 ◽  
Vol 104 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Rebecca L. Pearce ◽  
Jesse J. Wood ◽  
Yuri Artukhin ◽  
Timothy P. Birt ◽  
Martin Damus ◽  
...  
Keyword(s):  
British Columbia ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
North Pacific ◽  
Mitochondrial Control Region ◽  
Female Population ◽  
The North ◽  
Effective Female Population Size ◽  
High Gene ◽  
The North Pacific

Abstract Ancient Murrelets (Synthliboramphus antiquus) are subarctic seabirds that breed on islands from British Columbia through Alaska to China. In this study, we used sequence variation in the mitochondrial control region and cytochrome b gene to estimate the extent of genetic differentiation and gene flow among populations both within British Columbia and across the North Pacific. Results suggest that genetic differentiation is low and female-mediated gene flow is high among colonies within British Columbia, in agreement with banding studies. Surprisingly, genetic differentiation appears to be low and gene flow high between British Columbia and Asia. The effective female population size appears to be stable, but the species may have undergone a range expansion. These results suggest that Ancient Murrelets from throughout the North Pacific may represent a single management unit for conservation. El ADN Mitocondrial Sugiere Alto Flujo Génico en Synthliboramphus antiquus Resumen. Synthliboramphus antiquus es una especie de ave marina subártica que se reproduce en islas desde British Columbia a través de Alaska hasta China. En este estudio estimamos el grado de diferenciación genética y de flujo génico entre poblaciones localizadas dentro de British Columbia y a través del Pacífico Norte. Nos basamos en la variación en secuencias de la región control y el gen citocromo b del ADN mitocondrial. Los resultados sugieren baja diferenciación genética y alto flujo génico mediado por las hembras entre las colonias de British Columbia, lo que es consistente con estudios de aves anilladas. Sorprendentemente, la diferenciación genética parece ser baja y el flujo génico alto entre British Columbia y Asia. El tamaño efectivo de la población de hembras parece estar estable, pero la especie podría haber expandido su rango de distribución. Estos resultados sugieren que los S. antiquus de todo el Pacífico Norte pueden representar una sola unidad de manejo en términos de conservación.

scholarly journals Genetic differentiation in an endangered and strongly philopatric, migrant shorebird

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nelli Rönkä ◽  
Veli-Matti Pakanen ◽  
Angela Pauliny ◽  
Robert L. Thomson ◽  
Kimmo Nuotio ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Environmental Changes ◽  
Isolation By Distance ◽  
Population Subdivision ◽  
Genetic Structuring ◽  
Long Distance ◽  
Mobile Species ◽  
High Dispersal ◽  
The Baltic

Abstract Background Populations living in fragmented habitats may suffer from loss of genetic variation and reduced between-patch dispersal, which are processes that can result in genetic differentiation. This occurs frequently in species with reduced mobility, whereas genetic differentiation is less common among mobile species such as migratory birds. The high dispersal capacity in the latter species usually allows for gene flow even in fragmented landscapes. However, strongly philopatric behaviour can reinforce relative isolation and the degree of genetic differentiation. The Southern Dunlin (Calidris alpina schinzii) is a philopatric, long-distance migratory shorebird and shows reduced dispersal between isolated breeding patches. The endangered population of the Southern Dunlin breeding at the Baltic Sea has suffered from habitat deterioration and fragmentation of coastal meadows. We sampled DNA across the entire population and used 12 polymorphic microsatellite loci to examine whether the environmental changes have resulted in genetic structuring and loss of variation. Results We found a pattern of isolation-by-distance across the whole Baltic population and genetic differentiation between local populations, even within the southern Baltic. Observed heterozygosity was lower than expected throughout the range and internal relatedness values were positive indicating inbreeding. Conclusions Our results provide long-term, empirical evidence for the theoretically expected links between habitat fragmentation, population subdivision, and gene flow. They also demonstrate a rare case of genetic differentiation between populations of a long-distance migratory species. The Baltic Southern Dunlin differs from many related shorebird species that show near panmixia, reflecting its philopatric life history and the reduced connectivity of its breeding patches. The results have important implications as they suggest that reduced connectivity of breeding habitats can threaten even long-distance migrants if they show strong philopatry during breeding. The Baltic Southern Dunlin warrants urgent conservation efforts that increase functional connectivity and gene flow between breeding areas.

scholarly journals First microsatellite markers for the pine catkin sawfly Xyela concava (Hymenoptera, Xyelidae) and their application in phylogeography and population genetics

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8010
Author(s):  
Dustin Kulanek ◽  
Stephan M. Blank ◽  
Katja Kramp
Keyword(s):  
Population Genetics ◽  
Gene Flow ◽  
Nuclear Gene ◽  
Gene Region ◽  
Model Organisms ◽  
Dispersal Ability ◽  
Atpase Subunit ◽  
High Gene Flow ◽  
High Gene ◽  
Genetic Structures

Microsatellites are widely used as powerful markers in population genetics because of their ability to access recent genetic variation and to resolve subtle population genetic structures. However, their development, especially for non-model organisms with no available genome-wide sequence data has been difficult and time-consuming. Here, a commercial high-throughput sequencing approach (HTS) was used for the very first identification of microsatellite motifs in the genome of Xyela concava and the design of primer pairs flanking those motifs. Sixteen of those primer pairs were selected and implemented successfully to answer questions on the phylogeography and population genetics of X. concava. The markers were characterized in three geographically distinct populations of X. concava and tested for cross-species amplification in two additional Xyela and one Pleroneura species (Xyelidae). All markers showed substantial polymorphism as well as revealing subtle genetic structures among the three genotyped populations. We also analyzed a fragment of the nuclear gene region of sodium/potassium-transporting ATPase subunit alpha (NaK) and a partial mitochondrial gene region coding for cytochrome oxidase subunit I (COI) to demonstrate different genetic resolutions and sex-biased patterns of these markers, and their potential for combined use in future studies on the phylogeography and population genetics of X. concava. Although a limited number of populations was analyzed, we nevertheless obtained new insights on the latter two topics. The microsatellites revealed a generally high gene flow between the populations, but also suggested a deep historical segregation into two genetic lineages. This deep genetic segregation was confirmed by NaK. While the high gene flow was unexpected, because of assumed restricted dispersal ability of X. concava and the discontinuous distribution of the host trees between the populations, the segregation of two lineages is comprehensible and could be explained by different refuge areas of the hosts during glacial times. The COI results showed a discordant strong genetic structure between all populations, which might be explained by the smaller effective population size of the mitochondrial genome. However, given the frequent evidence of a similar nature in recent studies on sawflies, we also consider and discuss mitochondrial introgression on population level as an alternative explanation.

scholarly journals Population genetic structure of the rare species Eryngium maritimum L. (Apiaceae) in the Gulf of Gdańsk: implications for conservation and management

2012 ◽  
Vol 24 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Julita Minasiewicz ◽  
Sulisława Borzyszkowska ◽  
Katarzyna Żółkoś ◽  
Joanna Bloch-Orłowska ◽  
Renata Afranowicz
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Anthropogenic Factors ◽  
Significant Genetic Differentiation ◽  
Gulf Of Gdańsk ◽  
Low Levels ◽  
Gulf Of Gdansk ◽  
Genetic Structure And Diversity ◽  
Eryngium Maritimum

Abstract We examined the genetic structure and diversity of eight populations of Eryngium maritimum L. (Sea Holly) along 150 km coastline of the Gulf of Gdańsk in Poland. Allozyme electrophoresis revealed two polymorphic loci among the 31 we tested. The populations showed low levels of genetic diversity (P=6.25, A=1.062, Ht=0.026), with little genetic differentiation between populations (FST=0.03), although it was statistically significant (p<0.001). The main directions of currents and wind indicate no significant limitations to the transport of seeds between populations in the region. Therefore, the grouping of populations that are mostly congruent with their geographic locations (except HP1) might result from the low efficacy of gene flow by seeds. The significant genetic differentiation of HP1, even from close neighboring populations, might have arisen from the founder effect and barriers to the gene flow caused by anthropogenic factors such as forestation and the construction of breakwaters.

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