How many Archaeolacerta inhabit the Corso-Sardinian Plate? Allozyme variation and differentiation in Archaeolacerta bedriagae (Camerano, 1885)

2009 ◽  
Vol 30 (4) ◽  
pp. 463-470 ◽  
Author(s):  
Marco Bologna ◽  
Massimo Capula ◽  
Daniele Salvi ◽  
Pierluigi Bombi
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Morphological Traits ◽  
Taxonomic Status ◽  
Allozyme Variation ◽  
Morphometric Data ◽  
Allozyme Data ◽  
Rock Lizard ◽  
Low Levels

AbstractArchaeolacerta bedriagae is a rock lizard endemic to Corsica and Sardinia. Four subspecies have been recozied to date on the basis of morphological traits. Previous allozyme investigations revealed high genetic differentiation among populations of the species. Based on these results some authors hypothesized that more than one species of Archaeolacerta may occur on Corsica and Sardinia. In this paper we investigated allozyme variation at 19 gene loci in 5 populations belonging to all subspecies of A. bedriagae in order to study genetic differentiation among populations from Corsica and Sardinia, and to compare our results with those obtained in previous studies carried out on allozyme variation and taxonomy of the species. Low levels of genetic differentiation (average Nei's D = 0.026) and heterogeneity (mean FST = 0.147) were found comparing the A. bedriagae populations, and there was no evidence of interruption or restriction of gene flow. This is in agreement with the available molecular and morphometric data, while it is not in accordance with allozyme data reported in the previous studies. Our data do not support the hypothesis of an unrecognized criptic species of Archaeolacerta in Corsica and Sardinia, and indicate that the definitive assessment of the taxonomic status of the A. bedriagae populations requires further investigation.

Population genetic structure in duckweed (Lemna minor, Lemnaceae)

1996 ◽  
Vol 74 (2) ◽  
pp. 222-230 ◽  
Author(s):  
Christopher T. Cole ◽  
Martin I. Voskuil
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic ◽  
Lemna Minor ◽  
Vegetative Reproduction ◽  
Low Frequency ◽  
Morphological Differentiation ◽  
Genotypic Diversity ◽  
Allozyme Variation ◽  
Low Levels

Allozyme variation in 11 Minnesota populations of Lemna minor L. was studied, using 11 enzyme systems, resolving 16 putative loci from 285 plants. Significant deviations from Hardy–Weinberg frequencies occurred in several populations that had excesses of heterozygotes at several loci. While genotypic diversity and evenness measures are similar to other vegetatively reproducing plants (D = 0.541, E = 0.607), very few multilocus genotypes per population were found (mean = 4.0). Substantial population structure was evident (FST = 0.407), apparently reflecting low levels of gene flow (Nm = 0.30) despite the capacity of this species for dispersal of plantlets. This low level of gene flow and apparent low frequency of sexual reproduction has produced substantial levels of genetic divergence among populations, despite an absence of morphological differentiation. Keywords: allozymes, genetic structure, hydrophily, Lemna, vegetative dispersal, vegetative reproduction.

scholarly journals Population structure of Opisthorchis felineus (Trematoda) and its second intermediate hosts — cyprinid fishes in the Ob-Irtysh focus of opisthorchiasis, based on allozyme data

2014 ◽  
Vol 51 (4) ◽  
pp. 309-317 ◽  
Author(s):  
O. Zhigileva ◽  
V. Ozhireľev ◽  
T. Stepanova ◽  
T. Moiseenko
Keyword(s):  
Population Structure ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Allozyme Variation ◽  
Intermediate Hosts ◽  
Opisthorchis Felineus ◽  
Cyprinid Fishes ◽  
Low Levels

AbstractGenetic variability of West Siberian populations of Opisthorchis felineus and two species of cyprinid fish, its second intermediate hosts, was studied by isozyme analysis. Low levels of allozyme variation and genetic differentiation in O. felineus from the Ob-Irtysh focus of opisthorchiasis were detected. The proportion of polymorphic loci was 21.1 %, the average observed heterozygosity (Hobs) was 0.008, and expected heterozygosity (Hexp) was 0.052. For most loci in O. felineus deficit of heterozygotes (FIS = 0.7424) was observed. A comparison of population genetic structure of fish and parasites showed they were not congruent. Estimates of genetic differentiation of the parasite were smaller than for the fish — its intermediate host. Migration and population structure of the second intermediate hosts do not play an important role in formation of the population-genetic structure of O. felineus in the Ob-Irtysh focus of opisthorchiasis.

Allozyme variation in the Polygonum lapathifolium complex

1991 ◽  
Vol 69 (10) ◽  
pp. 2261-2270 ◽  
Author(s):  
Laurie L. Consaul ◽  
Suzanne I. Warwick ◽  
John McNeill
Keyword(s):  
North American ◽  
Taxonomic Status ◽  
Allozyme Variation ◽  
Genetic Distances ◽  
Allozyme Data ◽  
Separate Species ◽  
The North ◽  
Polygonum Lapathifolium ◽  
Polygonum Pensylvanicum ◽  
European Populations

The Polygonum lapathifolium complex consists of populations that are widely distributed in the Northern Hemisphere and that have been classified at different taxonomic levels. Allozyme data were used to test the current North American taxonomic status of members of the complex (including P. lapathifolium var. lapathifolium, P. lapathifolium var. salicifolium, and P. scabrum) and to verify diploidy in the P. lapathifolium complex and polyploid origins of the morphologically similar P. persicaria and P. pensylvanicum. Of the 15 enzyme systems surveyed in 50 populations of the complex, only 3 of the 23 loci (Acon, Lap, and Skdh) were polymorphic in the North American populations and a total of 6 loci in European populations. Fifteen multilocus genotypes were evident in the complex. Four genotypes (all with Lap-10.67 were exclusive to North American populations of P. lapathifolium, providing support for a North American element of the complex. Nine genotypes (all with Lap-10.63) were found in North American and European populations of P. scabrum, all European populations of the P. lapathifolium complex, and three populations of North American P. lapathifolium var. lapathifolium. Lap-10.67 was also found in the native tetraploid P. pensylvanicum, whereas Lap-10.63 was found in the introduced tetraploid P. persicaria. Genetic distances among populations did not support the current taxonomic divisions within the complex, nor did it support separate species status of P. scabrum. Allozyme data provided support for the allotetraploid origins of P. pensylvanicum and P. persicaria, with members of the P. lapathifolium complex as one of the parents of each. Key words: Polygonum lapathifolium, Polygonum scabrum, Polygonum pensylvanicum, Polygonum persicaria, allozymes.

scholarly journals Ocean Currents Drove Genetic Structure of Seven Dominant Mangrove Species Along the Coastlines of Southern China

2021 ◽  
Vol 12 ◽  
Author(s):  
Qifang Geng ◽  
Zhongsheng Wang ◽  
Jianmin Tao ◽  
Megumi K. Kimura ◽  
Hong Liu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
South China ◽  
Population Genetic ◽  
Ocean Currents ◽  
Mangrove Species ◽  
Contemporary Gene Flow ◽  
Low Levels ◽  
Oceanic Currents

Mangrove forest ecosystems, which provide important ecological services for marine environments and human activities, are being destroyed worldwide at an alarming rate. The objective of our study was to use molecular data and analytical techniques to separate the effects of historical and contemporary processes on the distribution of mangroves and patterns of population genetic differentiation. Seven mangrove species (Acanthus ilicifolius, Aegiceras corniculatum, Avicennia marina, Bruguiera gymnorrhiza, Kandelia obovata, Lumnitzera racemosa, and Rhizophora stylosa), which are predominant along the coastlines of South China, were genotyped at nuclear (nSSR) and chloroplast (cpSSR) microsatellite markers. We estimated historical and contemporary gene flow, the genetic diversity and population structure of seven mangrove species in China. All of these seven species exhibited few haplotypes, low levels of genetic diversity (HE = 0.160–0.361, with the exception of K. obovata) and high levels of inbreeding (FIS = 0.104–0.637), which may be due to their marginal geographical distribution, human-driven and natural stressors on habitat loss and fragmentation. The distribution patterns of haplotypes and population genetic structures of seven mangrove species in China suggest historical connectivity between populations over a large geographic area. In contrast, significant genetic differentiation [FST = 0.165–0.629 (nSSR); GST = 0.173–0.923 (cpSSR)] indicates that populations of mangroves are isolated from one another with low levels of contemporary gene flow among populations. Our results suggest that populations of mangroves were historically more widely inter-connected and have recently been isolated, likely through a combination of ocean currents and human activities. In addition, genetic admixture in Beibu Gulf populations and populations surrounding Hainan Island and southern mainland China were attributed to asymmetric gene flow along prevailing oceanic currents in China in historical times. Even ocean currents promote genetic exchanges among mangrove populations, which are still unable to offset the effects of natural and anthropogenic fragmentation. The recent isolation and lack of gene flow among populations of mangroves may affect their long-term survival along the coastlines of South China. Our study enhances the understanding of oceanic currents contributing to population connectivity, and the effects of anthropogenic and natural habitat fragmentation on mangroves, thereby informing future conservation efforts and seascape genetics toward mangroves.

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.

Allozyme variation and genetic divergence in the sand goby, Pomatoschistus minutus (Teleostei: Gobiidae)

2003 ◽  
Vol 83 (5) ◽  
pp. 1143-1149 ◽  
Author(s):  
S. Stefanni ◽  
E.S. Gysels ◽  
F.A.M. Volckaert ◽  
P.J. Miller
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Adriatic Sea ◽  
Allozyme Variation ◽  
Western Mediterranean ◽  
The Other ◽  
Sand Goby ◽  
Sea Levels ◽  
Pomatoschistus Minutus ◽  
The North

Samples of the widely distributed sand goby Pomatoschistus minutus have been investigated genetically from ten localities in the north-eastern Atlantic, North Sea, western Mediterranean and Adriatic Sea. Levels of genetic diversity and differentiation were assessed with starch (SGE) and cellulose acetate (CAGE) gel electrophoresis for 13 enzyme systems. Genetic differentiation between spatial samples points to a reduction or even absence of gene flow between the Adriatic and the other samples, including the western Mediterranean Sea (pair-wise FST=0.37 and 0.32 for SGE and CAGE respectively). The sample from the Adriatic Sea was clearly differentiated from the other samples at the lactate dehydrogenase loci LDH-A* (SGE and CAGE) and LDH-C* (CAGE). Values for genetic differentiation between Venetian and other sand gobies were of the same order of magnitude as between P. minutus and its closest relative P. lozanoi, suggesting allopatric speciation in the lagoon of Venice. At locations outside the Adriatic Sea, the sand goby has the typical features of a marine fish with a high level of gene flow and a low degree of genetic differentiation.

Genetic and morphological variation among populations of Oxyna parietina (Diptera: Tephritidae) across a European transect

1992 ◽  
Vol 70 (6) ◽  
pp. 1120-1128 ◽  
Author(s):  
Sabine Eber ◽  
Roland Brandl ◽  
Stefan Vidal
Keyword(s):  
Gene Flow ◽  
Morphological Variation ◽  
Gel Electrophoresis ◽  
Regional Scale ◽  
Allozyme Variation ◽  
Starch Gel Electrophoresis ◽  
Allozyme Data ◽  
Starch Gel ◽  
Wing Morphometrics ◽  
Morphological Patterns

Genetic and morphological variation in the phytophagous tephritid Oxyna parietina (L.) was investigated across a transect through Central Europe by starch-gel electrophoresis to detect allozyme variation and by wing morphometrics. Very low allozyme differentiation was found on both a local and a regional scale, and is best explained by high rates and distances of gene flow. Nevertheless, there exists a smooth cline of allele frequencies from northern to southern populations. We tentatively interpret this cline as being a consequence of selection by environmental factors. The morphological patterns are not consistent with the allozyme data.

scholarly journals GENETIC DIFFERENTIATION BETWEEN GEOGRAPHICALLY DISTANT POPULATIONS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1982 ◽  
Vol 101 (2) ◽  
pp. 235-256
Author(s):  
Rama S Singh ◽  
Donal A Hickey ◽  
Jean David
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Differentiation ◽  
Gene Frequency ◽  
Natural Populations ◽  
Allozyme Variation ◽  
Clinal Variation ◽  
Significant Genetic Differentiation ◽  
African Populations ◽  
Latitudinal Clines ◽  
North And South

ABSTRACT We have studied allozyme variation at 26 gene loci in nine populations of Drosophila melanogaster originating on five different continents. The distant populations show significant genetic differentiation. However, only half of the loci studied have contributed to this differentiation; the other half show identical patterns in all populations. The genetic differentiation in North American, European and African populations is correlated with the major climatic differences between north and south. These differences arise mainly from seven loci that show gene-frequency patterns suggestive of latitudinal clines in allele frequencies. The clinal variation is such that subtropical populations are more heterozygous than temperate populations. These results are discussed in relation to the selectionist and neutralist hypotheses of genetic variation in natural populations.

Shallow genetic divergence and distinct phenotypic differences between two Andean hummingbirds: Speciation with gene flow?

The Auk ◽  
2019 ◽  
Vol 136 (4) ◽  
Author(s):  
Catalina Palacios ◽  
Silvana García-R ◽  
Juan Luis Parra ◽  
Andrés M Cuervo ◽  
F Gary Stiles ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Incomplete Lineage Sorting ◽  
Lineage Sorting ◽  
Phenotypic Differences ◽  
Adaptive Mechanisms ◽  
The Face ◽  
Gloger’S Rule ◽  
Divergence With Gene Flow ◽  
Neutral Markers

Abstract Ecological speciation can proceed despite genetic interchange when selection counteracts the homogenizing effects of migration. We tested predictions of this divergence-with-gene-flow model in Coeligena helianthea and C. bonapartei, 2 parapatric Andean hummingbirds with marked plumage divergence. We sequenced putatively neutral markers (mitochondrial DNA [mtDNA] and nuclear ultraconserved elements [UCEs]) to examine genetic structure and gene flow, and a candidate gene (MC1R) to assess its role underlying divergence in coloration. We also tested the prediction of Gloger’s rule that darker forms occur in more humid environments, and examined morphological variation to assess adaptive mechanisms potentially promoting divergence. Genetic differentiation between species was low in both ND2 and UCEs. Coalescent estimates of migration were consistent with divergence with gene flow, but we cannot reject incomplete lineage sorting reflecting recent speciation as an explanation for patterns of genetic variation. MC1R variation was unrelated to phenotypic differences. Species did not differ in macroclimatic niches but were distinct in morphology. Although we reject adaptation to variation in macroclimatic conditions as a cause of divergence, speciation may have occurred in the face of gene flow driven by other ecological pressures or by sexual selection. Marked phenotypic divergence with no neutral genetic differentiation is remarkable for Neotropical birds, and makes C. helianthea and C. bonapartei an appropriate system in which to search for the genetic basis of species differences employing genomics.

The Use of Protein Electrophoresis for Determining Species Boundaries in Amphipods

Crustaceana ◽  
1993 ◽  
Vol 65 (2) ◽  
pp. 265-277 ◽  
Author(s):  
Barbara A. Stewart
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Morphological Variation ◽  
Protein Electrophoresis ◽  
Species Boundaries ◽  
Allopatric Populations ◽  
A Value ◽  
Electrophoretic Data

AbstractThe use of protein electrophoretic data for determining species boundaries in amphipods is addressed. Analysis of published literature on genetic differentiation in amphipods showed that pairs of allopatric populations which have genetic identities (I) above a value of 0.85 probably represent intraspecific populations, whereas pairs of populations which have genetic identities below about 0.45 probably represent different species. It was recommended that if I values fall between 0.45 and 0.85, additional factors such as evidence of a lack of gene flow between the populations, and concordant morphological variation should be considered.

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