scholarly journals Using neutral and outlier loci to uncover the genetic structure of 'Mytilus galloprovincialis' populations from the eastern Adriatic coast using population genetic and seascape genetic approaches

2021 ◽  
Author(s):  
◽  
Joanna Szondy Hamilton
Keyword(s):  
Genetic Structure ◽  
Mytilus Galloprovincialis ◽  
Blue Mussel ◽  
Strong Association ◽  
Outlier Locus ◽  
Outlier Loci ◽  
Adriatic Coast ◽  
Low Levels ◽  
Polymorphic Microsatellite ◽  
Highly Correlated

<p>The genetic variation of the Mediterranean blue mussel, Mytilus galloprovincialis from the eastern coastline of the Adriatic Sea was investigated using polymorphic microsatellite markers. In total, 843 individuals were sampled from 18 populations representing a variety of coastal environments in Croatia, Bosnia-Herzegovina, Montenegro and Albania. Neutral loci revealed low levels of genetic structure in this continuously distributed species, while one outlier locus, MGE7, which may be under selection, provided strong evidence of genetic structure. The distribution of one of the alleles of this locus, MGE7²⁴³, was significantly correlated with latitude. A genetic seascape analysis using 9 environmental and 3 geospatial variables revealed a strong association between MGE7²⁴³ and three highly correlated environmental variables, maximum sea surface temperature, minimum salinity and maximum chlorophyll-a. This association was maintained for homozygous genotypes for the MGE7²⁴³ allele, but not for heterozygotes, providing further evidence that the locus MGE7 may be under selection or closely linked to a gene under selection. These findings highlight how previously unrecognised genetic structure can be identified through the use of genetic seascape approaches.</p>

scholarly journals Using neutral and outlier loci to uncover the genetic structure of 'Mytilus galloprovincialis' populations from the eastern Adriatic coast using population genetic and seascape genetic approaches

2021 ◽  
Author(s):  
◽  
Joanna Szondy Hamilton
Keyword(s):  
Genetic Structure ◽  
Mytilus Galloprovincialis ◽  
Blue Mussel ◽  
Strong Association ◽  
Outlier Locus ◽  
Outlier Loci ◽  
Adriatic Coast ◽  
Low Levels ◽  
Polymorphic Microsatellite ◽  
Highly Correlated

<p>The genetic variation of the Mediterranean blue mussel, Mytilus galloprovincialis from the eastern coastline of the Adriatic Sea was investigated using polymorphic microsatellite markers. In total, 843 individuals were sampled from 18 populations representing a variety of coastal environments in Croatia, Bosnia-Herzegovina, Montenegro and Albania. Neutral loci revealed low levels of genetic structure in this continuously distributed species, while one outlier locus, MGE7, which may be under selection, provided strong evidence of genetic structure. The distribution of one of the alleles of this locus, MGE7²⁴³, was significantly correlated with latitude. A genetic seascape analysis using 9 environmental and 3 geospatial variables revealed a strong association between MGE7²⁴³ and three highly correlated environmental variables, maximum sea surface temperature, minimum salinity and maximum chlorophyll-a. This association was maintained for homozygous genotypes for the MGE7²⁴³ allele, but not for heterozygotes, providing further evidence that the locus MGE7 may be under selection or closely linked to a gene under selection. These findings highlight how previously unrecognised genetic structure can be identified through the use of genetic seascape approaches.</p>

scholarly journals Biogeographically significant units in conservation: a new integrative concept for conserving ecological and evolutionary processes

2019 ◽  
Vol 46 (4) ◽  
pp. 293-301 ◽  
Author(s):  
M Paula Quiroga ◽  
Lucia Castello ◽  
Vilma Quipildor ◽  
Andrea C Premoli
Keyword(s):  
Genetic Structure ◽  
Strong Association ◽  
Geographic Region ◽  
Landscape Conservation ◽  
Major Barrier ◽  
Distribution Maps ◽  
Genetic Barriers ◽  
Bibliographic Search ◽  
Molecular Information ◽  
Integrative Concept

SummaryWe combined tools of phylogeography, population genetics and biogeographical interpretation to analyse a group of phylogenetically independent lineages (animals and plants) that coexist within the same geographical region, yet under markedly different environments, in order to identify generalized barriers for gene flow. We tested the hypothesis that major geographic features have produced a concordant genetic structure in phylogenetically independent lineages. A rigorous bibliographic search was performed, selecting available molecular information from six taxa occupying distinct southern biomes of South America: Yungas, Prepuna, Puna and northern Monte. We estimated within-population genetic diversity, the genetic structure and haplotype phylogenies to assemble distribution maps of genetic barriers for each species. We found a strong association between genetic variation and latitudinal distribution of populations. We detected a major barrier for six taxa at 27°S latitude and a second one for a group of three species at 25–26°S. Two alternative non-exclusive hypotheses – geology and/or climate – explain concordant genetic barriers in divergent lineages. We suggest that the term ‘biogeographically significant units’ portrays a group of populations of phylogenetically unrelated taxa that inhabit the same geographic region that have been similarly impacted by major physical events, which can be used to identify priority areas in landscape conservation.

scholarly journals Genetic structure and dispersal patterns of the invasive psocid Liposcelis decolor (Pearman) in Australian grain storage systems

2010 ◽  
Vol 100 (5) ◽  
pp. 521-527 ◽  
Author(s):  
K.M. Mikac ◽  
N.N. FitzSimmons
Keyword(s):  
Genetic Structure ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Allelic Diversity ◽  
Mantel Test ◽  
Null Alleles ◽  
Dispersal Patterns ◽  
Long Distance ◽  
Population Comparisons ◽  
Low Levels

AbstractMicrosatellite markers were used to investigate the genetic structure among invasive L. decolor populations from Australia and a single international population from Kansas, USA to determine patterns of dispersal. Six variable microsatellites displayed an average of 2.5–4.2 alleles per locus per population. Observed (HO) heterozygosity ranged from 0.12–0.65 per locus within populations; but, in 13 of 36 tests, HO was less than expected. Despite low levels of allelic diversity, genetic structure estimated as θ was significant for all pairwise comparisons between populations (θ=0.05–0.23). Due to suspected null alleles at four loci, ENA (excluding null alleles) corrected FST estimates were calculated overall and for pairwise population comparisons. The ENA-corrected FST values (0.02–0.10) revealed significant overall genetic structure, but none of the pairwise values were significantly different from zero. A Mantel test of isolation by distance indicated no relationship between genetic structure and geographic distance among all populations (r2=0.12, P=0.18) and for Australian populations only (r2=0.19, P=0.44), suggesting that IBD does not describe the pattern of gene flow among populations. This study supports a hypothesis of long distance dispersal by L. decolor at moderate to potentially high levels.

scholarly journals Population genetic structure and variability in Lindera glauca (Lauraceae) indicates low levels of genetic diversity and skewed sex ratios in natural populations in mainland China

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8304 ◽  
Author(s):  
Biao Xiong ◽  
Limei Zhang ◽  
Shubin Dong ◽  
Zhixiang Zhang
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Isolation By Distance ◽  
Sex Ratios ◽  
Mainland China ◽  
Small Sample ◽  
Chloroplast Microsatellites ◽  
Wild Populations ◽  
Haplotype Networks ◽  
Low Levels

Lindera glauca (Lauraceae) is a tree of economic and ecological significance that reproduces sexually and asexually via apomictic seeds. It is widely distributed in the low-altitude montane forests of East Asia. Despite the potential implications of a mixed reproductive system in terms of genetic diversity, few studies have focused on this aspect. In this study, the genetic structure of wild populations of L. glauca was investigated via genetic analyses. Overall, 13 nuclear microsatellites (nSSRs) and five chloroplast microsatellites (cpSSRs) were used to genotype 300 individual plants, taken from 20 wild populations (a small sample size in some wild populations is due to the limitation of its specific reproduction, leading to certain limitations in the results of this study) and two cultivated populations ranging across nearly the entire natural distribution of mainland China. The populations exhibited low levels of genetic diversity (nSSR: AR = 1.75, Ho = 0.32, He = 0.36; cpSSR: Nb = 2.01, Hrs = 0.40), and no significant effect of isolation by distance between populations existed, regardless of marker type (nSSR: R2 = 0.0401, P = 0.068; cpSSR: R2 = 0.033, P = 0.091). Haplotype networks showed complex relationships among populations, and the H12 haplotype was predominant in most populations. Analyses of molecular variance obtained with nuclear markers (Fsc = 0.293, FST = 0.362) and chloroplast markers (Fsc = 0.299, FST = 0.312) were similar. The migration ratio of pollen flow versus seed flow in this study was negative (r = −1.149). Results suggest that weak barriers of dispersal between populations and/or the similarity of founders shared between neighbors and distant populations are indicative of the gene flow between populations more likely involving seeds. Wild L. glauca in mainland China was inferred to have highly skewed sex ratios with predominant females. In addition, some populations experienced a recent bottleneck effect, especially in Gujianshan, Chongqing, and southwest China (population GJS). It is suggested that few wild male individuals should be conserved in order to maintain overall genetic diversity in the wild populations of this species. These findings provide important information for the sustainable utilization and preservation of the overall genetic diversity of L. glauca.

Organotin compounds in seawater and Mytilus galloprovincialis mussels along the Croatian Adriatic Coast

2012 ◽  
Vol 64 (2) ◽  
pp. 189-199 ◽  
Author(s):  
Martina Furdek ◽  
Mitja Vahčič ◽  
Janez Ščančar ◽  
Radmila Milačič ◽  
Goran Kniewald ◽  
...  
Keyword(s):  
Mytilus Galloprovincialis ◽  
Organotin Compounds ◽  
Adriatic Coast

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.

Applications of microsatellite markers in studies of genetics and breeding of fish

2006 ◽  
Vol 3 (2) ◽  
pp. 83-87 ◽  
Author(s):  
Zhang Xiao-Gu ◽  
Tong Jin-Gou ◽  
Xiong Bang-Xi
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic ◽  
Germplasm Conservation ◽  
Genomic Mapping ◽  
Short Sequence ◽  
Sequence Repeat ◽  
Short Sequence Repeat ◽  
Food Fish ◽  
Polymorphic Microsatellite

AbstractThe microsatellite, or short sequence repeat (SSR), is a powerful genetic marker, useful in many areas of fish genetics and breeding. Polymorphic microsatellite loci have been frequently applied to the analysis of genetic diversity, population genetic structure, and genomic mapping. These co-dominant markers have also been applied to the classification and systematics, parentage identification, germplasm conservation, and breeding programme of food fish.

scholarly journals Genetic structure and biogeographic history of the Bicknell’s Thrush/ Gray-cheeked Thrush species complex

The Auk ◽  
2019 ◽  
Vol 137 (1) ◽  
Author(s):  
Alyssa M Fitzgerald ◽  
Jason Weir ◽  
Joel Ralston ◽  
Ian G Warkentin ◽  
Darroch M Whitaker ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Late Pleistocene ◽  
Species Complex ◽  
Extended Period ◽  
Genetic Data ◽  
Distribution Models ◽  
Biogeographic History ◽  
History Of ◽  
Low Levels ◽  
Bicknell's Thrush

Abstract We examined species limits, admixture, and genetic structure among populations in the Bicknell’s Thrush (Catharus bicknelli)–Gray-cheeked Thrush (C. minimus) species complex to establish the geographic and temporal context of speciation in this group, which is a model system in ecology and a high conservation priority. We obtained mitochondrial ND2 sequences from 186 Bicknell’s Thrushes, 77 Gray-cheeked Thrushes, and 55 individuals of their closest relative, the Veery (C. fuscescens), and genotyped a subset of individuals (n = 72) at 5,633 anonymous single nucleotide polymorphic (SNP) loci. Between-species sequence divergence was an order of magnitude greater than divergence within each species, divergence was dated to the late Pleistocene (420 kbp) based on Bayesian coalescence estimation, and a coalescent model (IMa) revealed almost no gene flow between species based on ND2. SNP data were consistent with mitochondrial results and revealed low levels of admixture among species (3 of 37 Bicknell’s Thrushes, no Gray-cheeked Thrushes, and no Veeries were &gt;2% admixed). Species distribution models projected to the Last Glacial Maximum suggest that Bicknell’s Thrush and Gray-cheeked Thrush resided in primarily allopatric refugia in the late Pleistocene, consistent with the genetic data that support reproductive isolation over an extended period of time. Our genetic data suggest that both species underwent demographic expansions, possibly as they expanded out of Pleistocene refugia into their current ranges. We conclude that Bicknell’s Thrush and Gray-cheeked Thrush are 2 distinct species-level lineages despite low levels of Gray-cheeked Thrush introgression in Bicknell’s Thrushes, and divergence has been maintained by a long history of allopatry in subtly different habitats. Their unique phylogeography among boreal forest birds indicates that either cryptic species breaks in eastern North America are still undiscovered, or another factor, such as divergent natural selection, high migratory connectivity, or interspecific competition, played a role in their divergence.

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