scholarly journals Seasonal Migration and Genetic Population Structure in House Wrens

The Condor ◽  
2000 ◽  
Vol 102 (3) ◽  
pp. 517-528 ◽  
Author(s):  
Nidia Arguedas ◽  
Patricia G. Parker
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Migratory Birds ◽  
Seasonal Migration ◽  
Population Subdivision ◽  
Migratory Behavior ◽  
Genetic Population ◽  
Neotropical Migrant ◽  
House Wrens ◽  
Migrant Birds

Abstract Neotropical migrant birds have undergone significant changes in population size, due in part to alterations in the landscape in their breeding range. Some alterations have resulted in the isolation of areas containing optimal habitat for breeding. Isolation between habitat fragments could reduce gene flow between populations, which might result in loss of genetic variation due to genetic drift. To test whether isolation due to distance between populations may affect migratory birds as much as sedentary birds, we used four microsatellite loci as genetic markers to compare gene flow and population structure in migratory and sedentary House Wrens (Troglodytes aedon and T. musculus, respectively). If migratory behavior enhanced gene flow, we expected to find that populations of migratory birds were genetically more similar than populations of sedentary birds, and that gene flow declined more rapidly with distance in sedentary than in migratory populations. Blood samples were collected from 18–25 migratory House Wrens at each of six sites in Ohio separated by distances from 25 to over 300 km, and from 16–20 sedentary House Wrens at each of six sites in Costa Rica, also at distances up to 350 km. We used heterologous microsatellite primers to obtain estimates for RST (population subdivision) and Nm (number of immigrants per generation) in relation to distance between pairs of populations. In the migratory populations, Mantel permutational tests showed no effect of distance on RST or Nm at distances between 25 and 300 km. In the sedentary birds, RST increased and Nm decreased significantly as distance between populations increased from 25 to 300 km. FST values were not different from those obtained using Slatkin's (1995) RST statistics. These results are consistent with our hypothesis that migratory behavior enhances gene flow.

scholarly journals Genetic population structure of mangrove jack, Lutjanus argentimaculatus (Forsskål)

2003 ◽  
Vol 54 (2) ◽  
pp. 127 ◽  
Author(s):  
Jennifer R. Ovenden ◽  
Raewyn Street
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Allelic Variation ◽  
Gene Diversity ◽  
Haplotype Diversity ◽  
Genetic Population Structure ◽  
Western Coast ◽  
Base Pairs ◽  
Genetic Population ◽  
Lutjanus Argentimaculatus

Translocations of mangrove jack, Lutjanus argentimaculatus (Forsskål 1775), to increase angling opportunities in artificial impoundments are foreshadowed in Queensland. To evaluate genetic population structure before translocations occur, mangrove jack were collected from three sites on the Queensland coast and from one site on the north-western coast of Western Australia. Allelic variation at four dinucleotide microsatellite loci was high: gene diversity (heterozygosity) ranged from 0.602 to 0.930 and allelic counts from 10 to 24. Genetic differentiation among collection sites was weak: estimates of FST were 0.002 for all four sites, and less (FST = 0.001) across a major biogeographical boundary (the Torres Strait region). Nucleotide sequence from two mitochondrial regions (control, 375 base pairs, and ATPase, 415 base pairs) was obtained from a subset of the Australian and additional Indo-Pacific (Indonesian and Samoan) mangrove jack. Haplotype diversity was high (control region, 33 haplotypes for 34 fish; ATPase region, 13 haplotypes for 56 fish). Phylogenetic analysis of mitochondrial DNA sequence data could not discern a relationship between tree topology and geography. These results suggest that mangrove jack in Queensland, and possibly throughout Australia, experience high levels of gene flow. The artificial gene flow caused by permitted translocations is unlikely to exceed natural levels. Fine-scale ecological matching between donor and recipient populations may increase stocking success, and is important if translocation is needed as a species recovery tool in the future.

scholarly journals Genetic population structure of the round whitefish (Prosopium cylindraceum) in North America: multiple markers reveal glacial refugia and regional subdivision

2018 ◽  
Vol 75 (6) ◽  
pp. 836-849 ◽  
Author(s):  
Thomas D. Morgan ◽  
Carly F. Graham ◽  
Andrew G. McArthur ◽  
Amogelang R. Raphenya ◽  
Douglas R. Boreham ◽  
...  
Keyword(s):  
Population Structure ◽  
North America ◽  
Great Lakes ◽  
Lake Ontario ◽  
Glacial Refugia ◽  
Lake Huron ◽  
Genetic Population Structure ◽  
Population Subdivision ◽  
Source Population ◽  
Genetic Population

Round whitefish (Prosopium cylindraceum) have a broad, disjunct range across northern North America and Eurasia, and little is known about their genetic population structure. We performed genetic analyses of round whitefish from 17 sites across its range using nine microsatellites, two mitochondrial DNA (mtDNA) loci, and 4918 to 8835 single-nucleotide polymorphism (SNP) loci. Our analyses identified deep phylogenetic division between eastern and western portions of the range, likely indicative of origins from at least two separate Pleistocene glacial refugia. Regionally, microsatellites and SNPs identified congruent patterns in subdivision, and population structure was consistent with expectations based on hydrologic connectivity. Within the Laurentian Great Lakes, Lake Huron and Lake Ontario were identified as key areas of interest. Lake Huron appears to be a contemporary source population for several other Great Lakes, and Lake Ontario contains a genetically discrete group of round whitefish. In all cases, multiple genetic markers yielded similar patterns, but SNPs offered substantially enhanced resolution. We conclude that round whitefish have population subdivision on several scales important for understanding their evolutionary history and conservation planning.

Genetic population structure of the fairy shrimp Branchinecta coloradensis (Anostraca) in the Rocky Mountains of Colorado

1998 ◽  
Vol 76 (11) ◽  
pp. 2049-2057 ◽  
Author(s):  
Andrew J Bohonak
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Rocky Mountains ◽  
Regional Scale ◽  
Local Scale ◽  
Genetic Population Structure ◽  
Fairy Shrimp ◽  
Genetic Population ◽  
Contemporary Gene Flow ◽  
Branchinecta Coloradensis

Dispersal rates for freshwater invertebrates are often inferred from population genetic data. Although genetic approaches can indicate the amount of isolation in natural populations, departures from an equilibrium between drift and gene flow often lead to biased gene flow estimates. I investigated the genetic population structure of the pond-dwelling fairy shrimp Branchinecta coloradensis in the Rocky Mountains of Colorado, U.S.A., using allozymes. Glaciation in this area and the availability of direct dispersal estimates from previous work permit inferences regarding the relative impacts of history and contemporary gene flow on population structure. Hierarchical F statistics were used to quantify differentiation within and between valleys (thetaSV and thetaVT, respectively). Between valleys separated by 5-10 km, a high degree of differentiation (thetaVT = 0.77) corresponds to biologically reasonable gene flow estimates of 0.07 individuals per generation, although it is possible that this value represents founder effects and nonequilibrium conditions. On a local scale (<=110 m), populations are genetically similar (thetaSV = 0.13) and gene flow is estimated to be 1.7 individuals exchanged between ponds each generation. This is very close to an ecological estimate of dispersal for B. coloradensis via salamanders. Gene flow estimates from previous studies on other Anostraca are also similar on comparable geographic scales. Thus, population structure in B. coloradensis appears to be at or near equilibrium on a local scale, and possibly on a regional scale as well.

scholarly journals Genetic population structure of the blue sea star Linckia laevigata in the Visayas (Philippines)

2015 ◽  
pp. 1-7 ◽  
Author(s):  
Diana Sr Alcazar ◽  
Marc Kochzius
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Flow ◽  
Comparative Analysis ◽  
Marine Invertebrates ◽  
Genetic Population Structure ◽  
Sea Star ◽  
Genetic Population ◽  
Gene Coi ◽  
Linckia Laevigata

Coral reef associated marine invertebrates, such as the blue sea starLinckia laevigata, have a life history with two phases: sedentary adults and planktonic larvae. On the one hand it is hypothesised that the long pelagic larval duration facilitates large distance dispersal. On the other hand, complex oceanographic and geographic characteristics of the Visayan seascape could cause isolation of populations. The study aims to investigate the genetic diversity, genetic population structure and gene flow inL. laevigatato reveal connectivity among populations in the Visayas. The analysis is based on partial sequences (626 bp in length) of the mitochondrial cytochrome oxidase I gene (COI) from 124 individuals collected from five localities in the Visayas. A comparative analysis of these populations with populations from the Indo-Malay Archipelago (IMA) published previously is also presented. Genetic diversity was high (h = 0.98, π = 1.6%) and comparable with preceding studies. Analyses of molecular variance (AMOVA) revealed a lack of spatial population differentiation among sample sites in the Visayas (ΦST-value = 0.009;P &gt; 0.05). The lack of genetic population structure indicates high gene flow among populations ofL. laevigatain the Visayas. Comparative analysis with data from the previous study indicates high connectivity of the Visayas with the central part of the IMA.

scholarly journals Genetic population structure of Gyrodactylus thymalli (Monogenea) in a large Norwegian river system

Parasitology ◽  
2015 ◽  
Vol 142 (14) ◽  
pp. 1693-1702 ◽  
Author(s):  
RUBEN ALEXANDER PETTERSEN ◽  
TOR ATLE MO ◽  
HAAKON HANSEN ◽  
LEIF ASBJØRN VØLLESTAD
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Gene Flow ◽  
Haplotype Diversity ◽  
River System ◽  
Genetic Population Structure ◽  
Restricted Gene Flow ◽  
Upstream Migration ◽  
Genetic Population ◽  
Long Time

SUMMARYThe extent of geographic genetic variation is the result of several processes such as mutation, gene flow, selection and drift. Processes that structure the populations of parasite species are often directly linked to the processes that influence the host. Here, we investigate the genetic population structure of the ectoparasite Gyrodactylus thymalli Žitňan, 1960 (Monogenea) collected from grayling (Thymallus thymallus L.) throughout the river Glomma, the largest watercourse in Norway. Parts of the mitochondrial dehydrogenase subunit 5 (NADH 5) and cytochrome oxidase I (COI) genes from 309 G. thymalli were analysed to study the genetic variation and investigated the geographical distribution of parasite haplotypes. Three main clusters of haplotypes dominated the three distinct geographic parts of the river system; one cluster dominated in the western main stem of the river, one in the eastern and one in the lower part. There was a positive correlation between pairwise genetic distance and hydrographic distance. The results indicate restricted gene flow between sub-populations of G. thymalli, most likely due to barriers that limit upstream migration of infected grayling. More than 80% of the populations had private haplotypes, also indicating long-time isolation of sub-populations. According to a molecular clock calibration, much of the haplotype diversity of G. thymalli in the river Glomma has developed after the last glaciation.

scholarly journals Population Structure, Pathogenicity, and Mating Type Distribution of Magnaporthe oryzae Isolates from East Africa

2015 ◽  
Vol 105 (8) ◽  
pp. 1137-1145 ◽  
Author(s):  
Geoffrey Onaga ◽  
Kerstin Wydra ◽  
Birger Koopmann ◽  
Yakouba Séré ◽  
Andreas von Tiedemann
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
East Africa ◽  
Mating Type ◽  
Magnaporthe Oryzae ◽  
Geographic Origin ◽  
The Philippines ◽  
Genetic Population ◽  
Principal Coordinates

Rice blast, caused by Magnaporthe oryzae, is one of the emergent threats to rice production in East Africa (EA), where little is known about the population genetics and pathogenicity of this pathogen. We investigated the genetic diversity and mating type (MAT) distribution of 88 isolates of M. oryzae from EA and representative isolates from West Africa (WA) and the Philippines (Asia) using amplified fragment length polymorphism markers and mating-type-specific primer sets. In addition, the aggressiveness of each isolate was evaluated by inoculating on the susceptible Oryza sativa indica ‘Co39’, scoring the disease severity and calculating the disease progress. Hierarchical analysis of molecular variance revealed a low level of genetic differentiation at two levels (FST 0.12 and FCT 0.11). No evidence of population structure was found among the 65 isolates from EA, and gene flow among EA populations was high. Moreover, pairwise population differentiation (GST) in EA populations ranged from 0.03 to 0.04, suggesting that >96% of genetic variation is derived from within populations. However, the populations from Asia and WA were moderately differentiated from EA ones. The spatial analysis of principal coordinates and STRUCTURE revealed overlapping between individual M. oryzae isolates from EA, with limited distinctness according to the geographic origin. All the populations were clonal, given the positive and significant index of association (IA) and standardized index of association (rd), which indicates a significant (P < 0.001) departure from panmixia (IA and rd = 0). Both MAT1-1 and MAT1-2 were detected. However, MAT1-1 was more prevalent than MAT1-2. Pathogenicity analysis revealed variability in aggressiveness, suggesting a potential existence of different races. Our data suggest that either M. oryzae populations from EA could be distributed as a single genetic population or gene flow is exerting a significant influence, effectively swamping the action of selection. This is the first study of genetic differentiation of rice-infecting M. oryzae strains from EA, and may guide further studies on the pathogen as well as resistance breeding efforts.

Genetic and phenotypic population structure of the Coenonympha tullia complex (Lepidoptera: Nymphalidae: Satyrinae) in California: no evidence for species boundaries

1988 ◽  
Vol 66 (12) ◽  
pp. 2751-2765 ◽  
Author(s):  
Adam H. Porter ◽  
Hansjürg Geiger
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Electrophoretic Analysis ◽  
Species Boundaries ◽  
Genetic Population ◽  
River Drainage ◽  
Migration Rates ◽  
The North ◽  
Northern Nevada ◽  
Very High

Decisions regarding species status of taxa showing geographic replacement are explicit hypotheses about population structure. The structure of 21 populations of the Coenonympha tullia group from northern California, southwestern Oregon, and northern Nevada was analyzed for evidence of reproductive isolation. These samples included five subspecies (california, eryngii, ampelos, eunomia, and mono) nominally placed in three species (california, ampelos, and ochracea). We found very high intra- and inter-population variability in the "diagnostic" wing pattern characters used by previous authors. There is evidence of intergradation between eryngii and eunomia in southwestern Oregon, and between california and ampelos in the eastern Feather River drainage in California. A complex cline involving California, eryngii, and ampelos occurs in the Pit River drainage of northeastern California. The taxon mono appears distinct, apparently because of an absence of Coenonympha populations in the expected mono–ampelos contact area. Electrophoretic analysis of the same 21 populations showed very high intrapopulation genetic variability (expected heterozygosity = 13.5–20.4%, percentage of polymorphic loci (most common allele < 99%) = 35.5–58.8%; 14 alleles at the locus for phosphoglucose isomerase (one population with 11 alleles)). However, interpopulation (geographic) variability was extremely low. Standardized genetic variance among populations (FST, using Wright's formulation) in contact zones indicates that gene flow is probably uninterrupted between the subspecies california, eryngii, ampelos, and eunomia. FST values for the isocitrate dehydrogenase locus indicate that present-day gene flow is probably unimportant in maintaining similarity between ampelos and mono. The genetic population structure is reminiscent of highly vagile colonizing species, but this may be largely historical, due to post-Pleistocene range changes rather than high present-day interpopulation migration rates. We conclude that all California populations are conspecific. Only the subspecies mono is clearly separated from the others, at the level 0.034 (Nei's unbiased distance), approximating that of weak subspecies in other taxa. The North American entities should all be provisionally classified as subspecies of the holarctic species tullia unless evidence is found to support their separation.

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